2021年03月, 2020年度日本天文学会欧文研究報告論文賞, Mass constraint for a planet in a protoplanetary disk from the gap width, 日本天文学会
Kazuhiro D. Kanagawa;Takayuki Muto;Hidekazu Tanaka;Takayuki Tanigawa;Taku Takeuchi;Takashi Tsukagoshi;Munetake Momose
国内学会・会議・シンポジウム等の賞

2018年03月15日, 2017年度日本天文学会欧文研究報告論文賞, Local Enhancement of the Surface Density in the Protoplanetary Ring Surrounding HD 142527, 日本天文学会
Misato Fukagawa;Takashi Tsukagoshi;Munetake Momose
国内学会・会議・シンポジウム等の賞

2018年03月, 2017年度日本天文学会欧文研究報告論文賞, Local Enhancement of the Surface Density in the Protoplanetary Ring Surrounding HD 142527, 日本天文学会
Misato Fukagawa;Takashi Tsukagoshi;Munetake Momose 他15名
国内学会・会議・シンポジウム等の賞

Observationally derived magnetic field strength and 3D components in the HD 142527 disk
Satoshi Ohashi; Takayuki Muto; Yusuke Tsukamoto; Akimasa Kataoka; Takashi Tsukagoshi; Munetake Momose; Misato Fukagawa; Nami Sakai
Nature Astronomy, 2025年02月05日

Revealing asymmetry on mid-plane of protoplanetary disc through modelling of axisymmetric emission: methodology
Masataka Aizawa; Takayuki Muto; Munetake Momose, ABSTRACT

This study proposes an analytical framework for deriving the surface brightness profile and geometry of a geometrically thin axisymmetric disc from interferometric observation of continuum emission. Such precise modelling facilitates the exploration of faint non-axisymmetric structures, such as spirals and circumplanetary discs. As a demonstration, we simulate interferometric observations of geometrically thin axisymmetric discs. The proposed method can reasonably recover the injected axisymmetric structures, whereas Gaussian fitting of the same data yielded larger errors in disc orientation estimation. To further test the applicability of the method, it was applied to the mock data for $m=1,2$ spirals and a point source, which are embedded in a bright axisymmetric structure. The injected non-axisymmetric structures were reasonably recovered except for the innermost parts, and the disc geometric parameter estimations were better than Gasussian fitting. The method was then applied to the real data of Elias 20 and AS 209, and it adequately subtracted the axisymmetric component, notably in Elias 20, where substantial residuals remained without our method. We also applied our method to continuum data of PDS 70 to demonstrate the effectiveness of the method. We successfully recovered emission from PDS 70 c consistently with previous studies, and also tentatively discovered new substructures. The current formulation can be applied to any data for disc continuum emission, and aids in the search of spirals and circumplanetary discs, whose detection is still limited., Oxford University Press (OUP)
Monthly Notices of the Royal Astronomical Society, 2024年06月25日

Frequencies of Warm Debris Disks Based on Point Source Catalogs of Spitzer, WISE, and Gaia
Toshiyuki Mizuki; Munetake Momose; Masataka Aizawa; Hiroshi Kobayashi, Abstract

More than a thousand warm debris disks have been detected as infrared excess at mid-infrared wavelengths, and their frequencies have been obtained for various spectral types of stars. However, the dependence of the frequencies on spectral type is still debated because the number of stars with significant and detectable infrared excess is limited. Herein, we present the largest systematic search for infrared excess using data from Gaia, WISE, and Spitzer. We identified 373, 485, and 255-reliable infrared excesses in the mid-infrared archival data at wavelengths of 12, 22, and 24 μm for WISE/W3, W4, and Spitzer/MIPS ch1, respectively. Although we confirmed that more massive stars tend to show higher frequencies of debris disks, these disk frequencies are relatively flat for both low- and intermediate-mass stars, with a jump at 7000 K for all three wavelengths. Assuming that bright, warm debris disks have lifetimes of a few to several hundred million years, the disk frequency can be understood as the ratio between the timescale and the upper limits of the sample ages. We also found that intermediate-mass stars with infrared excess tend to be bluer and fainter along the evolutionary track than those without, implying that massive stars hosting debris disks are relatively young, with an isochronal age of approximately 500 Myr. These tendencies are reasonably explained by a standard scenario in which debris disks are likely to be produced by collisions of planetesimals in the early stages of stellar evolution, such as the Late Heavy Bombardment., American Astronomical Society
The Astronomical Journal, 2024年05月20日

Kinematic signatures of a low-mass planet with a moderately inclined orbit in a protoplanetary disk
Kazuhiro D Kanagawa; Tomohiro Ono; Munetake Momose, Abstract
A planet embedded in a protoplanetary disk produces a gap by disk–planet interaction. It also generates velocity perturbation of gas, which can also be observed as deviations from the Keplerian rotation in the channel map of molecular line emission, called kinematic planetary features. These observed signatures provide clues to determine the mass of the planet. We investigated the features induced by a planet with an inclined orbit through three-dimensional hydrodynamic simulations. We found that a smaller planet, with an inclination of ∼10○–20○, can produce kinematic features as prominent as those induced by a massive coplanar planet. Despite the kinematic features being similar, the gap is shallower and narrower compared with the case in which the kinematic features are formed by a coplanar planet. We also found that the kinematic features induced by an inclined planet were fainter for rarer CO isotopologues because the velocity perturbation is weaker at the position closer to the midplane, which was different in the case with a coplanar massive planet. This dependence on the isotopologues is distinguished if the planet has an inclined orbit. We discussed two observed kinematic features in the disk of HD 163296. We concluded that the kink observed at 220 au can be induced by an inclined planet, while the kink at 67 au is consistent to that induced by a coplanar planet.
Publications of the Astronomical Society of Japan, 2023年12月09日

Dust Enrichment and Grain Growth in a Smooth Disk around the DG Tau Protostar Revealed by ALMA Triple Bands Frequency Observations
Satoshi Ohashi; Munetake Momose; Akimasa Kataoka; Aya E Higuchi; Takashi Tsukagoshi; Takahiro Ueda; Claudio Codella; Linda Podio; Tomoyuki Hanawa; Nami Sakai; Hiroshi Kobayashi; Satoshi Okuzumi; Hidekazu Tanaka, Abstract

Characterizing the physical properties of dust grains in a protoplanetary disk is critical to comprehending the planet formation process. Our study presents Atacama Large Millimeter/submillimeter Array (ALMA) high-resolution observations of the young protoplanetary disk around DG Tau at a 1.3 mm dust continuum. The observations, with a spatial resolution of ≈0.″04, or ≈5 au, revealed a geometrically thin and smooth disk without substantial substructures, suggesting that the disk retains the initial conditions of the planet formation. To further analyze the distributions of dust surface density, temperature, and grain size, we conducted a multiband analysis with several dust models, incorporating ALMA archival data of the 0.87 and 3.1 mm dust polarization. The results showed that the Toomre Q parameter is ≲2 at a 20 au radius, assuming a dust-to-gas mass ratio of 0.01. This implies that a higher dust-to-gas mass ratio is necessary to stabilize the disk. The grain sizes depend on the dust models, and for the DSHARP compact dust, they were found to be smaller than ∼400 μm in the inner region (r ≲ 20 au) while exceeding larger than 3 mm in the outer part. Radiative transfer calculations show that the dust scale height is lower than at least one-third of the gas scale height. These distributions of dust enrichment, grain sizes, and weak turbulence strength may have significant implications for the formation of planetesimals through mechanisms such as streaming instability. We also discuss the CO snowline effect and collisional fragmentation in dust coagulation for the origin of the dust size distribution., American Astronomical Society
The Astrophysical Journal, 2023年08月28日, ［査読有り］

Multiple Rings and Asymmetric Structures in the Disk of SR 21
Yi Yang; Hauyu Baobab Liu; Takayuki Muto; Jun Hashimoto; Ruobing Dong; Kazuhiro Kanagawa; Munetake Momose; Eiji Akiyama; Yasuhiro Hasegawa; Takashi Tsukagoshi; Mihoko Konishi; Motohide Tamura
The Astrophysical Journal, 2023年05月01日, ［査読有り］

ALMA Band 6 high-resolution observations of the transitional disk around SY Chamaeleontis
Orihara; Ryuta; Momose; Munetake; Muto; Takayuki; Hashimoto; Jun; Liu; Hauyu Baobab; Tsukagoshi; Takashi; Kudo; Tomoyuki; Takahashi; Sanemichi; Yang; Yi; Hasegawa; Yasuhiro; Dong; Ruobing; Konishi; Mihoko; Akiyama; Eiji, Abstract

In this study, we reported the results of high-resolution (${0{^{\prime \prime}_{. } }14}$) Atacama Large Millimeter/submillimeter Array (ALMA) observations of the 225 GHz dust continuum and CO molecular emission lines from the transitional disk around SY Cha. Our high-resolution observations clearly revealed the inner cavity and the central point source for the first time. The radial profile of the ring can be approximated by a bright narrow ring superimposed on a fainter wide ring. Furthermore, we found that there is a weak azimuthal asymmetry in dust continuum emission. For gas emissions, we detected 12CO(2–1), 13CO(2–1), and C18O(2–1), from which we estimated the total gas mass of the disk to be 2.2 × 10−4 M ⊙ , assuming a CO/H2 ratio of 10−4. The observations showed that the gas is present inside the dust cavity. The analysis of the velocity structure of the 12CO(2–1) emission line revealed that the velocity is distorted at the location of the dust inner disk, which may be owing to a warping of the disk or radial gas flow within the cavity of the dust disk. High-resolution observations of SY Cha showed that this system is composed of a ring and a distorted inner disk, which may be common, as indicated by the survey of transitional disk systems at a resolution of ${\sim},{0{^{\prime \prime}_{. } }1}$., Oxford University Press (OUP)
Publications of the Astronomical Society of Japan, 2023年04月, ［査読有り］

Dippers from TESS Full-frame Images. II. Spectroscopic Characterization of Four Young Dippers
Kasagi; Yui; Kotani; Takayuki; Kawahara; Hajime; Tajiri; Tomoyuki; Muto; Takayuki; Aizawa; Masataka; Fujii; Michiko S.; Hattori; Kohei; Masuda; Kento; Momose; Munetake; Ohsawa; Ryou; Takita; Satoshi, Photometric monitoring by the Transiting Exoplanet Survey Satellite (TESS) has discovered not only periodic signals by transiting exoplanets but also episodic or quasiperiodic dimming around young stellar objects. The dimming mechanisms of these objects, the so-called "dippers," are thought to be related to either the accretion property or the structure of protoplanetary disks especially in regions close to the host star. Recently, we have created a catalog of dippers from one year of TESS full-frame image data. In this paper, we report on the spectral features of four newly found dippers in that catalog and show that they potentially shed light on the dimming mechanisms. We found that all of the targets exhibit the H alpha emission line, which is an indicator of ongoing accretion. Based on their line profiles and/or their variability, we characterized the properties of the disks of each source, which can support dimming mechanisms via a dusty disk wind or an accretion-driven inner-disk warp. Also, we found an interesting dipper (TIC 317873721), a "close-in binary dipper," showing a complex variability of the line profile and a large radial velocity variation. Because the dimming intervals are similar to the orbital period of the binary, we suggest that the dips are caused by dust in the accretion warp from a circumbinary disk onto stars. Such a close-in (<0.1 au) binary dipper has been rarely reported thus far; further investigation will reveal new aspects of disk evolution and planetary formation., IOP Publishing Ltd
The Astrophysical Journal Supplement Series, 2022年04月, ［査読有り］

The formation of planetary systems with SPICA
Kamp; I. search by orcid ; Honda; M. ; Nomura; H. ; Audard; M. ; Fedele; D. ; Waters; L. B. F. M. ; Aikawa; Y. ; Banzatti; A. ; Bowey; J. E. ; Bradford; M. ; Dominik; C. ; Furuya; K. ; Habart; E. ; Ishihara; D. ; Johnstone; D. search by orcid ; Kennedy; G. search by orcid ; Kim; M. ; Kral; Q. ; Lai; S. -P. ; Larsson; B. McClure; M. ; Miotello; A. ; Momose; M. ; Nakagawa; T. ; Naylor; D. ; Nisini; B. search by orcid ; Notsu; S. ; Onaka; T. ; Pantin; E. ; Podio; L. ; Riviere Marichalar; P. ; Rocha; W. R. M. ; Roelfsema; P. ; Shimonishi; T. ; Tang; Y. -W. ; Takami; M. ; Tazaki; R. ; Wolf; S. ; Wyatt; M. ; Ysard; N.,
In this era of spatially resolved observations of planet-forming disks with Atacama Large Millimeter Array (ALMA) and large ground-based telescopes such as the Very Large Telescope (VLT), Keck, and Subaru, we still lack statistically relevant information on the quantity and composition of the material that is building the planets, such as the total disk gas mass, the ice content of dust, and the state of water in planetesimals. SPace Infrared telescope for Cosmology and Astrophysics (SPICA) is an infrared space mission concept developed jointly by Japan Aerospace Exploration Agency (JAXA) and European Space Agency (ESA) to address these questions. The key unique capabilities of SPICA that enable this research are (1) the wide spectral coverage



$10{-}220\,\mu\mathrm{m}$


, (2) the high line detection sensitivity of



$(1{-}2) \times 10^{-19}\,\mathrm{W\,m}^{-2}$


with



$R \sim 2\,000{-}5\,000$


in the far-IR (SAFARI), and



$10^{-20}\,\mathrm{W\,m}^{-2}$


with



$R \sim 29\,000$


in the mid-IR (SPICA Mid-infrared Instrument (SMI), spectrally resolving line profiles), (3) the high far-IR continuum sensitivity of 0.45 mJy (SAFARI), and (4) the observing efficiency for point source surveys. This paper details how mid- to far-IR infrared spectra will be unique in measuring the gas masses and water/ice content of disks and how these quantities evolve during the planet-forming period. These observations will clarify the crucial transition when disks exhaust their primordial gas and further planet formation requires secondary gas produced from planetesimals. The high spectral resolution mid-IR is also unique for determining the location of the snowline dividing the rocky and icy mass reservoirs within the disk and how the divide evolves during the build-up of planetary systems. Infrared spectroscopy (mid- to far-IR) of key solid-state bands is crucial for assessing whether extensive radial mixing, which is part of our Solar System history, is a general process occurring in most planetary systems and whether extrasolar planetesimals are similar to our Solar System comets/asteroids. We demonstrate that the SPICA mission concept would allow us to achieve the above ambitious science goals through large surveys of several hundred disks within



$\sim\!2.5$


months of observing time., Cambridge University Press (CUP)
Publications of the Astronomical Society of Australia, 2021年11月03日, ［査読有り］

Transmission Electron Microscopy Study of the Morphology of Ices Composed of H2O, CO2, and CO on Refractory Grains
Kouchi; Akira; Tsuge; Masashi; Hama; Tetsuya; Oba; Yasuhiro; Okuzumi; Satoshi; Sirono; Sin-iti; Momose; Munetake; Nakatani; Naoki; Furuya; Kenji; Shimonishi; Takashi; Yamazaki; Tomoya; Hidaka; Hiroshi; Kimura; Yuki; Murata; Ken-ichiro; Fujita; Kazuyuki; Nakatsubo; Shunichi; Tachibana; Shogo; Watanabe; Naoki, American Astronomical Society
The Astrophysical Journal, 2021年09月, ［査読有り］

Erratum: Dust Polarization in Four Protoplanetary Disks at 3 mm: Further Evidence of Multiple Origins (Astrophysical Journal Letters (2019) 877 (L2) DOI: 10.3847/2041-8213/ab1e46)
Rachel E. Harrison; Leslie W. Looney; Ian W. Stephens; Zhi-Yun Li; Haifeng Yang; Akimasa Kataoka; Robert J. Harris; Woojin Kwon; Takayuki Muto; Munetake Momose, 1. Results We have identified an error in the beam sizes reported in Table 1 of the original Letter. The beam sizes for RY Tau and MWC 480 were transposed in the table. We present the correct beam sizes for all sources here. We have also identivied an error in the reported mass of Haro 6-13. The protostar’s mass was quoted as 0.55 M⊙ while the mass reported in Schaefer et al. (2009) is 1.00 ± 0.15 M⊙. In addition, we identified an error in our mapping script that misrepresented the percent polarization scale bars in Figure 1 and the right column of Figures 4 and 5 in the original Letter. The original scale bars were too large by a factor of two. We present the corrected figures here. These errors do not affect the conclusions of the Letter. (Table presented) (Figure presented)., American Astronomical Society
Astrophysical Journal Letters, 2021年08月20日

Formation of chiral CO polyhedral crystals on icy interstellar grains
Kouchi; Akira; Tsuge; Masashi; Hama; Tetsuya; Niinomi; Hiromasa; Nakatani; Naoki; Shimonishi; Takashi; Oba; Yasuhiro; Kimura; Yuki; Sirono; Sin-iti; Okuzumi; Satoshi; Momose; Munetake; Furuya; Kenji; Watanabe; Naoki,
The crystallinity and morphology of solid carbon monoxide (CO) on icy interstellar grains were examined by observing the deposition, crystallization, and UV and electrons irradiation of solid CO using transmission electron microscopy. Herein, we found that solid CO deposited in molecular clouds was crystalline, and that even if amorphous CO was deposited, amorphous CO crystallized within 103 yr at 10 K. Conversely, crystalline CO was not amorphized by UV rays or electron beam at 10 K. These results indicated the occurrence of chiral crystalline CO instead of amorphous CO in space. Furthermore, the large surface diffusion coefficients of CO on eamorphous H2O and crystalline CO at 10 K facilitated the morphological equilibration of crystalline CO. Bad wetting of crystalline CO with amorphous H2O proved that the morphology of the ice grains was not spherical with an onion-like structure, as hitherto assumed, but rather it was a polyhedral crystalline CO attached to amorphous H2O. This has important implications for phenomena associated with the collision and subsequent sticking between ice grains, surface chemical reactions, non-thermal desorption of molecules and the origin of homochirality in interstellar biomolecules., Oxford University Press (OUP)
Monthly Notices of the Royal Astronomical Society, 2021年07月, ［査読有り］

ALMA observation of the protoplanetary disk around WW Cha: faint double-peaked ring and asymmetric structure
Munetake Momose, We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations of dust continuum emission of the disk around WW Cha. The dust continuum image shows a smooth disk structure with a faint (low-contrast) dust ring, extending from $\sim 40$ au to $\sim 70$ au, not accompanied by any gap. We constructed the simple model to fit the visibility of the observed data by using MCMC method and found that the bump (we call the ring without the gap the bump) has two peaks at $40$ au and $70$ au. The residual map between the model and observation indicates asymmetric structures at the center and the outer region of the disk. These asymmetric structures are also confirmed by model-independent analysis of the imaginary part of the visibility. The asymmetric structure at the outer region is consistent with a spiral observed by SPHERE. To constrain physical quantities of the disk (dust density and temperature), we carried out radiative transfer simulations. We found that the midplane temperature around the outer peak is close to the freezeout temperature of CO on water ice ($\sim 30$ K). The temperature around the inner peak is about $50$ K, which is close to the freezeout temperature of H$_2$S and also close to the sintering temperature of several species. We also discuss the size distribution of the dust grains using the spectral index map obtained within the Band 6 data.
The Astrophysical Journal, 2021年03月19日, ［査読有り］

ALMA Observations of the Inner Cavity in the Protoplanetary Disk around Sz 84
Jun Hashimoto; Takayuki Muto; Ruobing Dong; Yasuhiro Hasegawa; Nienke van der Marel; Motohide Tamura; Michihiro Takami; Munetake Momose, American Astronomical Society
The Astrophysical Journal, 2021年02月01日, ［査読有り］

Observations of the [C I] (3P1-3P0) emission toward the massive star-forming region RCW 38: Further evidence for highly-clumped density distribution of the molecular gas
Izumi; Natsuko; Fukui; Yasuo; Tachihara; Kengo; Fujita; Shinji; Torii; Kazufumi; Kamazaki; Takeshi; Kaneko; Hiroyuki; Silva; Andrea; Iono; Daisuke; Momose; Munetake; Sugimoto; Kanako; Nakazato; Takeshi; Kosugi; George; Maekawa; Jun; Takahashi; Shigeru; Yoshino; Akira; Asayama; Shin'ichiroFukui; Yasuo; Tachihara; Kengo; Fujita; Shinji; Torii; Kazufumi; Kamazaki; Takeshi; Kaneko; Hiroyuki; Silva; Andrea; Iono; Daisuke; Momose; Munetake; Sugimoto; Kanako; Nakazato; Takeshi; Kosugi; George; Maekawa; Jun; Takahashi; Shigeru; Yoshino; Akira; Asayama; Shin'ichiro, Abstract

We present observations of the 3P1–3P0 fine-structure line of atomic carbon using the ASTE 10m sub-mm telescope towards RCW 38, the youngest super star cluster in the Milky Way. The detected [C i] emission is compared with the CO J = 1–0 image cube presented in Fukui et al. (2016, ApJ, 820, 26) which has an angular resolution of 40″ (∼0.33 pc). The overall distribution of the [C i] emission in this cluster is similar to that of the 13CO emission. The optical depth of the [C i] emission was found to be τ = 0.1–0.6, suggesting mostly optically thin emission. An empirical conversion factor from the [C i] integrated intensity to the H2 column density was estimated as X[C i]$= 6.3 \times 10 ^{20}\:$cm−2 K−1 km−1 s (for visual extinction: AV ≤ 10 mag) and 1.4 × 1021 cm−2 K−1 km−1 s (for AV of 10–100 mag). The column density ratio of the [C i] to CO (N[C i]$/N_{\rm CO}$) was derived as ∼0.1 for AV of 10–100 mag, which is consistent with that of the Orion cloud presented in Ikeda et al. (2002, ApJ, 571, 560). However, our results cover an AV regime of up to 100 mag, which is wider than the coverage found in Orion, which reaches up to ∼60 mag. Such a high [C i]$/$CO ratio in a high-AV region is difficult to explain via the plane-parallel photodissociation region model, which predicts that this ratio is close to 0 due to the heavy shielding of the ultraviolet (UV) radiation. Our results suggest that the molecular gas in this cluster is highly clumpy, allowing deep penetration of UV radiation even at averaged AV values of 100 mag. Recent theoretical works have presented models consistent with such clumped gas distribution with a sub-pc clump size (e.g., Tachihara et al. 2018, arXiv:1811.02224)., Oxford University Press (OUP)
Publications of the Astronomical Society of Japan, 2021年02月, ［査読有り］

Dippers from the TESS Full-frame Images. I. Results of the First One Year Data and Discovery of a Runaway Dipper
Tomoyuki Tajiri; Hajime Kawahara; Masataka Aizawa; Michiko S. Fujii; Kohei Hattori; Yui Kasagi; Takayuki Kotani; Kento Masuda; Munetake Momose; Takayuki Muto; Ryou Ohsawa; Satoshi Takita
The Astrophysical Journal Supplement Series, 2020年12月01日, ［査読有り］

GW Ori: Interactions between a Triple-star System and Its Circumtriple Disk in Action
Bi, J; van der Marel, N; Dong, R; Muto, T; Martin, R. G; Smallwood, J. L; Hashimoto, J; Liu, H. B; Nomura, H; Hasegawa, Y; Takami, M; Konishi, M; Momose, M; Kanagawa, K. D; Kataoka, A; Ono, T; Sitko, M. L; Takahashi, S. Z; Tomida, K; Tsukagoshi, T, Abstract

GW Ori is a hierarchical triple system with a rare circumtriple disk. We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of 1.3 mm dust continuum and ¹²CO J = 2 − 1 molecular gas emission of the disk. For the first time, we identify three dust rings in the GW Ori disk at ∼46, 188, and 338 au, with estimated dust mass of 74, 168, and 245 Earth masses, respectively. To our knowledge, its outermost ring is the largest dust ring ever found in protoplanetary disks. We use visibility modeling of dust continuum to show that the disk has misaligned parts, and the innermost dust ring is eccentric. The disk misalignment is also suggested by the CO kinematics. We interpret these substructures as evidence of ongoing dynamical interactions between the triple stars and the circumtriple disk., American Astronomical Society
The Astrophysical Journal, 2020年05月, ［査読有り］

The Detection of Dust Gap-ring Structure in the Outer Region of the CR Cha Protoplanetary Disk
Kim, S; Takahashi, S; Nomura, H; Tsukagoshi, T; Lee, S; Muto, T; Dong, R; Hasegawa, Y; Hashimoto, J; Kanagawa, K; Kataoka, A; Konishi, M; Liu, H. B; Momose, M; Sitko, M; Tomida, K, We observe the dust continuum at 225 GHz and CO isotopologue ((CO)-C-12, (CO)-C-13, and (CO)-O-18) J = 2-1 emission lines toward the CR Cha protoplanetary disk using the Atacama Large Millimeter/submillimeter Array. The dust continuum image shows a dust gap-ring structure in the outer region of the dust disk. A faint dust ring is also detected around 120 au beyond the dust gap. The CO isotopologue lines indicate that the gas disk is more extended than the dust disk. The peak brightness temperature of the (CO)-C-13 line shows a small bump around 130 au, while (CO)-C-12 lines do not. We investigate two possible mechanisms for reproducing the observed dust gap-ring structure and a gas temperature bump. First, the observed gap structure can be opened by a Jupiter-mass planet using the relation between the planet mass and the gap depth and width. Meanwhile, the radiative transfer calculations based on the observed dust surface density profile show that the observed dust ring could be formed by dust accumulation at the gas temperature bump, that is, the gas pressure bump produced beyond the outer edge of the dust disk., IOP PUBLISHING LTD
The Astrophysical Journal, 2020年01月, ［査読有り］

Subaru Near-infrared Imaging Polarimetry of Misaligned Disks around the SR 24 Hierarchical Triple System
Mayama, Satoshi; Pérez, Sebastián; Kusakabe, Nobuhiko; Muto, Takayuki; Tsukagoshi, Takashi; Sitko, Michael L.; Takami, Michihiro; Hashimoto, Jun; Dong, Ruobing; Kwon, Jungmi; Hayashi, Saeko S.; Kudo, Tomoyuki; Kuzuhara, Masayuki; Follette, Katherine; Fukagawa, Misato; Momose, Munetake; Oh, Daehyeon; de Leon, Jerome; Akiyama, Eiji; Wisniewski, John P. Yang, Yi; Abe, Lyu; Brandner, Wolfgang; Brandt, Timothy D.; Bonnefoy, Michael; Carson, Joseph C.; Chilcote, Jeffrey; Currie, Thayne; Feldt, Markus; Goto, Miwa; Grady, Carol A.; Groff, Tyler; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiko; Henning, Thomas; Hodapp, Klaus W.; Ishii, Miki; Iye, Masanori; Janson, Markus; Jovanovic, Nemanja; Kandori, Ryo; Kasdin, Jeremy; Knapp, Gillian R.; Lozi, Julien; Martinache, Frantz; Matsuo, Taro; McElwain, Michael W.; Miyama, Shoken; Morino, Jun-Ichi; Moro-Martin, Amaya; Nakagawa, Takao; Nishimura, Tetsuo; Pyo, Tae-Soo; Rich, Evan A.; Serabyn, Eugene; Suto, Hiroshi; Suzuki, Ryuji; Takato, Naruhisa; Terada, Hiroshi; Thalmann, Christian; Tomono, Daigo; Turner, Edwin L.; Watanabe, Makoto; Yamada, Toru; Takami, Hideki; Usuda, Tomonori; Uyama, Taichi; Tamura, Motohide, Abstract

The SR 24 multistar system hosts both circumprimary and circumsecondary disks, which are strongly misaligned with each other. The circumsecondary disk is circumbinary in nature. Interestingly, both disks are interacting, and they possibly rotate in opposite directions. To investigate the nature of this unique twin disk system, we present 0.″1 resolution near-infrared polarized intensity images of the circumstellar structures around SR 24, obtained with HiCIAO mounted on the Subaru 8.2 m telescope. Both the circumprimary disk and the circumsecondary disk are resolved and have elongated features. While the position angle of the major axis and radius of the near-IR (NIR) polarization disk around SR 24S are 55° and 137 au, respectively, those around SR 24N are 110° and 34 au, respectively. With regard to overall morphology, the circumprimary disk around SR 24S shows strong asymmetry, whereas the circumsecondary disk around SR 24N shows relatively strong symmetry. Our NIR observations confirm the previous claim that the circumprimary and circumsecondary disks are misaligned from each other. Both the circumprimary and circumsecondary disks show similar structures in ¹²CO observations in terms of its size and elongation direction. This consistency is because both NIR and ¹²CO are tracing surface layers of the flared disks. As the radius of the polarization disk around SR 24N is roughly consistent with the size of the outer Roche lobe, it is natural to interpret the polarization disk around SR 24N as a circumbinary disk surrounding the SR 24Nb–Nc system., American Astronomical Society
The Astronomical Journal, 2020年01月, ［査読有り］

HD142527に付随する原始惑星系円盤のガス・ダスト比　　　　　　　　　　　　　　　
スン・カンロウ,百瀬宗武,武藤恭之,塚越崇,片岡章雅,花輪知幸,深川美里,西合一矢,芝井広
日本惑星科学会誌, 2019年12月25日, ［査読有り］

Nobeyama 45 m mapping observations toward Orion A. I. Molecular Outflows
Tanabe, Yoshihiro; Nakamura, Fumitaka; Tsukagoshi, Takashi; Shimajiri, Yoshito; Ishii, Shun; Kawabe, Ryohei; Feddersen, Jesse R.; Kong, Shuo; Arce, Hector G.; Bally, John; Carpenter, John M.; Momose, Munetake, ラスト(シニア)オーサー, We conducted an exploration of ¹²CO molecular outflows in the Orion A giant molecular cloud to investigate outflow feedback using ¹²CO (J=1-0) and ¹³CO (J=1-0) data obtained by the Nobeyama 45 m telescope. In the region excluding the center of OMC 1, we identified 44 ¹²CO (including 17 newly detected) outflows based on the unbiased and systematic procedure of automatically determining the velocity range of the outflows and separating the cloud and outflow components. The optical depth of the ¹²CO emission in the detected outflows is estimated to be approximately 5. The total momentum and energy of the outflows, corrected for optical depth, are estimated to be 1.6×10²M☉ km s^-1 and 1.5×10⁴⁶ egs, respectively. The momentum and energy ejection rate of the outflows are estimated to be 36% and 235% of the momentum and energy dissipation rates of the cloud turbulence, respectively. Furthermore, the ejection rates of the outflows are comparable to those of the expanding molecular shells estimated by Feddersen et al. (2018, ApJ, 862, 121). Cloud turbulence cannot be sustained by the outflows and shells unless the energy conversion efficiency is as high as 20%....
Publications of the Astronomical Society of Japan, 2019年12月, ［査読有り］

Nobeyama 45-m mapping observations toward nearby molecular clouds, Orion A, Aquila Rift, and M17: Project overview
Fumitaka Nakamura; Shun Ishii; Kazuhito Dobashi; Tomomi Shimoikura; Yoshito Shimajiri; Ryohei Kawabe; Yoshihiro Tanabe; Asha Hirose; Shuri Oyamada; Yumiko Urasawa; Hideaki Takemura; Takashi Tsukagoshi; Munetake Momose; Koji Sugitani; Ryoichi Nishi; Sachiko Okumura; Patricio Sanhueza; Quang Nygen-Luong; Takayoshi Kusune, Oxford University Press ({OUP})
Publications of the Astronomical Society of Japan, 2019年12月, ［査読有り］

Nobeyama 45 m mapping observations toward Orion A. III. Multi-line observations toward an outflow-shocked region, Orion Molecular Cloud 2 FIR 4
Nakamura, Fumitaka; Oyamada, Shuri; Okumura, Sachiko; Ishii, Shun; Shimajiri, Yoshito; Tanabe, Yoshihiro; Tsukagoshi, Takashi; Kawabe, Ryohei; Momose, Mumetake; Urasawa, Yumiko; Nishi, Ryoichi; Lin, Sheng-Jun; Lai, Shih-Ping; Dobashi, Kazuhito; Shimoikura, Tomomi; Sugitani, Koji, We present the results of mapping observations toward an outflow-shocked region, OMC-2 FIR 4, using the Nobeyama 45 m telescope. We observed the area in ¹³CO (J = 1-0), C¹⁸O (J = 1-0), N₂H⁺ (J = 1-0), CCS (J_N = 8₇-7₆), HCO⁺ (J = 1-0), H¹³CO⁺ (J = 1-0), HN¹³C (J = 1-0), H¹³CN (J = 1-0), DNC (J = 1-0), N₂D⁺ (J = 1-0), and DC₃N (J = 9-8). We detected a dense molecular clump that contains FIR 4/5. We also detected, in the ¹³CO line, blueshifted and redshifted components driven presumably by protostellar outflows in this region. The axes of the FIR 3 and VLA 13 outflows, projected on the plane of the sky, appear to point to the FIR 4 clump, suggesting that it may be compressed by protostellar outflows from Class I sources, FIR 3 and VLA 13. Applying a hyperfine fit of N₂H⁺ lines, we estimated the excitation temperature to be ∼20 K. The high excitation temperature is consistent with the fact that the clump contains protostars. CCS emission was detected in this region for the first time. Its abundance is estimated to be a few × 10^-12, indicating that the region is chemically evolved at ∼10⁵ yr, which is comparable to the typical lifetime of Class I protostars. This timescale is consistent with the scenario that star formation in FIR 4 is triggered by dynamical compression of the protostellar outflows. The [HNC]/[HCN] ratio was evaluated to be ∼0.5 in the dense clump and the outflow lobes, whereas it is somewhat larger in the envelope of the dense clump. The small [HNC]/[HCN] ratio indicates that HNC formation was prevented due to high temperatures. Such high temperatures seem to be consistent with the scenario that either protostellar radiation, or outflow compression, or both affected the thermal properties of this region....
Publications of the Astronomical Society of Japan, 2019年12月, ［査読有り］

Investigating the gas-to-dust ratio in the protoplanetary disk of HD 142527
Kang-Lou Soon; Munetake Momose; Takayuki Muto; Takashi Tsukagoshi; Akimasa Kataoka; Tomoyuki Hanawa; Misato Fukagawa; Kazuya Saigo; Hiroshi Shibai, 責任著者
Publications of the Astronomical Society of Japan, 2019年12月01日, ［査読有り］

First Subarcsecond Submillimeter-wave [C i] Image of 49 Ceti with ALMA
Aya E. Higuchi; Kazuya Saigo; Hiroshi Kobayashi; Kazunari Iwasaki; Munetake Momose; Kang Lou Soon; Nami Sakai; Masanobu Kunitomo; Daisuke Ishihara; Satoshi Yamamoto, American Astronomical Society
The Astrophysical Journal, 2019年10月01日, ［査読有り］

原始惑星系円盤の電波観測入門(1)：惑星系の母胎を探る　　　　　　　　　　　　　　　
百瀬 宗武
日本惑星科学会誌, 2019年09月25日, ［査読有り］

An Observational Study for Grain Dynamics in the AS 209 Disk with Submillimeter Polarization*
Tomohiro Mori; Akimasa Kataoka; Satoshi Ohashi; Munetake Momose; Takayuki Muto; Hiroshi Nagai; Takashi Tsukagoshi
The Astrophysical Journal, 2019年09月20日, ［査読有り］

Dust Polarization in Four Protoplanetary Disks at 3 mm: Further Evidence of Multiple Origins
Rachel E. Harrison; Leslie W. Looney; Ian W. Stephens; Zhi-Yun Li; Haifeng Yang; Akimasa Kataoka; Robert J. Harris; Woojin Kwon; Takayuki Muto; Munetake Momose, American Astronomical Society
The Astrophysical Journal Letters, 2019年05月20日, ［査読有り］

The Flared Gas Structure of the Transitional Disk around Sz 91
Takashi Tsukagoshi; Munetake Momose; Yoshimi Kitamura; Masao Saito; Ryohei Kawabe; Sean Andrews; David Wilner; Tomoyuki Kudo; Jun Hashimoto; Nagayoshi Ohashi; Motohide Tamura
The Astrophysical Journal, 2019年01月20日, ［査読有り］

Two Different Grain Size Distributions within the Protoplanetary Disk around HD 142527 Revealed by ALMA Polarization Observation
Satoshi Ohashi; Akimasa Kataoka; Hiroshi Nagai; Munetake Momose; Takayuki Muto; Tomoyuki Hanawa; Misato Fukagawa; Takashi Tsukagoshi; Kohji Murakawa; Hiroshi Shibai
The Astrophysical Journal, 2018年09月01日, ［査読有り］

High-contrast Polarimetry Observation of the T Tau Circumstellar Environment
Yi Yang; Satoshi Mayama; Saeko S. Hayashi; Jun Hashimoto; Roman Rafikov; Eiji Akiyama; Thayne Currie; Markus Janson; Munetake Momose; Takao Nakagawa; Daehyeon Oh; Tomoyuki Kudo; Nobuhiko Kusakabe; Lyu Abe; Wolfgang Brandner; Timothy D. Brandt; Joseph C. Carson; Sebastian Egner; Markus Feldt; Miwa Goto; Carol A. Grady; Olivier Guyon; Yutaka Hayano; Masahiko Hayashi; Thomas Henning; Klaus W. Hodapp; Miki Ishii; Masanori Iye; Ryo Kandori; Gillian R. Knapp; Jungmi Kwon; Masayuki Kuzuhara; Taro Matsuo; Michael W. Mcelwain; Shoken Miyama; Jun-Ichi Morino; Amaya Moro-martin; Tetsuo Nishimura; Tae-Soo Pyo; Eugene Serabyn; Takuya Suenaga; Hiroshi Suto; Ryuji Suzuki; Yasuhiro H. Takahashi; Michihiro Takami; Naruhisa Takato; Hiroshi Terada; Christian Thalmann; Edwin L. Turner; Makoto Watanabe; John Wisniewski; Toru Yamada; Hideki Takami; Tomonori Usuda; Motohide Tamura, We conducted high-contrast polarimetry observations of T Tau in the H-band, using the High Contrast Instrument for the Subaru Next Generation Adaptive Optics instrument mounted on the Subaru Telescope, revealing structures as near as 0 1 from the stars T Tau N and T Tau S. The whole T Tau system is found to be surrounded by nebulalike envelopes, and several outflow-related structures are detected in these envelopes. We analyzed the detailed polarization patterns of the circumstellar structures near each component of this triple young star system and determined constraints on the circumstellar disks and outflow structures. We suggest that the nearly face-on circumstellar disk of T Tau N is no larger than 0.''8, or 117 au, in the northwest, based on the existence of a hole in this direction, and no larger than 0.''27, or 40 au, in the south. A new structure, "N5," extends to about 0.''42, or 59 au, southwest of the star, and is believed to be part of the disk. We suggest that T Tau S is surrounded by a highly inclined circumbinary disk with a radius of about 0.''3, or 44 au, with a position angle of about 30 degrees, that is misaligned with the orbit of the T Tau S binary. After analyzing the positions and polarization vector patterns of the outflow-related structures, we suggest that T Tau S should trigger the well-known E-W outflow, and is also likely to be responsible for a southwest precessing outflow "coil" and a possible south outflow., IOP PUBLISHING LTD
ASTROPHYSICAL JOURNAL, 2018年07月, ［査読有り］

The fundamental stellar parameters of FGK stars in the SEEDS survey Norman, OK 73071, USA
Evan A. Rich; John P. Wisniewski; Michael W. McElwain; Jun Hashimoto; Tomoyuki Kudo; Nobuhiko Kusakabe; Yoshiko K. Okamoto; Lyu Abe; Eiji Akiyama; Wolfgang Brandner; Timothy D. Brandt; Phillip Cargile; Joseph C. Carson; Thayne M. Currie; Sebastian Egner; Markus Feldt; Misato Fukagawa; Miwa Goto; Carol A. Grady; Olivier Guyon; Yutaka Hayano; Masahiko Hayashi; Saeko S. Hayashi; Leslie Hebb; Krzysztof G. Helminiak; Thomas Henning; Klaus W. Hodapp; Miki Ishii; Masanori Iye; Markus Janson; Ryo Kandori; Gillian R. Knapp; Masayuki Kuzuhara; Jungmi Kwon; Taro Matsuo; Satoshi Mayama; Shoken Miyama; Munetake Momose; Jun-Ichi Morino; Amaya Moro-Martin; Takao Nakagawa; Tetsuo Nishimura; Daehyeon Oh; Tae-Soo Pyo; Joshua Schlieder; Eugene Serabyn; Michael L. Sitko; Takuya Suenaga; Hiroshi Suto; Ryuji Suzuki; Yasuhiro H. Takahashi; Michihiro Takami; Naruhisa Takato; Hiroshi Terada; Christian Thalmann; Daigo Tomono; Edwin L. Turner; Makoto Watanabe; Toru Yamada; Hideki Takami; Tomonori Usuda; Motohide Tamura, Large exoplanet surveys have successfully detected thousands of exoplanets to-date. Utilizing these detections and non-detections to constrain our understanding of the formation and evolution of planetary systems also requires a detailed understanding of the basic properties of their host stars. We have determined the basic stellar properties of F, K and G stars in the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey from Echelle spectra taken at the Apache Point Observatory's 3.5m telescope. Using ROBOSPECT to extract line equivalent widths and TemperatureGravity microtrubulentVelocity ITerations to calculate the fundamental parameters, we have computed T-eff, log(g), v(t), [Fe/H], chromospheric activity and the age for our sample. Our methodology was calibrated against previously published results for a portion of our sample. The distribution of [Fe/H] in our sample is consistent with that typical of the Solar neighbourhood. Additionally, we find the ages of most of our sample are < 500 Myr, but note that we cannot determine robust ages from significantly older stars via chromospheric activity age indicators. The futuremeta-analysis of the frequency ofwide stellar and sub-stellar companions imaged via the SEEDS survey will utilize our results to constrain the occurrence of detected comoving companions with the properties of their host stars., OXFORD UNIV PRESS
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2017年12月, ［査読有り］

The shortest periodic and flaring flux variability of a methanol maser emission at 6.7 GHz in G 014.23−00.50
Sugiyama, Koichiro; Nagase, Katsura; Yonekura, Yoshinori; Momose, Munetake; Yasui, Yasutaka; Saito, Yu; Motogi, Kazuhito; Honma, Mareki; Hachisuka, Kazuya; Matsumoto, Naoko; Uchiyama, Mizuho; Fujisawa, Kenta
Publications of the Astronomical Society of Japan, 2017年08月, ［査読有り］

The shortest periodic and flaring flux variability of a methanol maser emission at 6.7 GHz in G 014.23-00.50
Koichiro Sugiyama; Katsura Nagase; Yoshinori Yonekura; Munetake Momose; Yasutaka Yasui; Yu Saito; Kazuhito Motogi; Mareki Honma; Kazuya Hachisuka; Naoko Matsumoto; Mizuho Uchiyama; Kenta Fujisawa, We detected flaring flux variability that regularly occurred with a period of 23.9 d on a 6.7 GHz methanol maser emission at V-lsr = 25.30 km s(-1) in G 014.23-00.50 through highly frequent monitoring using the Hitachi 32m radio telescope. Analyzing data from 2013 January 5 to 2016 January 21, the periodic variability has persisted in at least 47 cycles, corresponding to similar to 1100 d. The period of 23.9 d is the shortest one observed in masers around high-mass young stellar objects so far. The flaring component normally falls below the detection limit (3 sigma) of similar to 0.9 Jy. In the flaring periods, the component rises above the detection limit with a ratio of the peak flux density more than 180 in comparison with the quiescent phase, showing intermittent periodic variability. The timescale of the flux rise was typically two days or shorter, and both symmetric and asymmetric profiles of flux variability were observed through intraday monitoring. These characteristics might be explained by a change in the flux of seed photons in a colliding-wind binary (CWB) system, or a variation of the dust temperature by the extra heating source of a shock formed by a CWB system within a gap region in a circumbinary disk, in which the orbital semi-major axes of the binary are 0.26-0.34 au., OXFORD UNIV PRESS
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 2017年08月, ［査読有り］

A Circumstellar Disk around HD 169142 in the Mid-Infrared (N-Band)
Yoshiko Kataza Okamoto; Hirokazu Kataza; M. Honda; T. Yamashita; T. Fujiyoshi; T. Miyata; S. Sako; H. Fujiwara; I. Sakon; M. Fukagawa; M. Momose; T. Onaka, The Herbig Ae star HD 169142 is one of the objects that show complex structure, such as multiple (innermost, middle, and outer) disks, gaps, and unresolved sources. We made N-band (8-13 mu m) observations of HD 169142 with the Cooled Mid-Infrared Camera and Spectrometer on the 8.2 m Subaru Telescope. The images are spatially resolved out to an similar to 1 '' radius in all the observed bands. We made a simple disk model composed of an unresolved central source (representing the innermost disk/halo) and the ring at a radius r similar to 25 au (corresponding to the. inner wall or edge of a middle disk at similar to 25-40 au). The radial intensity profile within the central region (less than or similar to 0.'' 3 or less than or similar to 40 au) is well reproduced by the model. Furthermore, we subtracted the model image from the observed one to search for additional structures. In the model-subtracted images, we found an unresolved west. source separated by 17.0 +/- 2.9 au in the direction of position angle. 260 degrees +/- 5 degrees from the original emission peak, which is supposed to correspond to the position of the central star, and a bright east. arc located at r similar to 60 au. The west. source is different from the L'-band unresolved source recently found in coronagraphic observations. It could be a structure related to planet formation in the disk, such as a circumplanetary disk or clumpy disk structure. The east. arc corresponds to the inner wall or edge of the outer disk., IOP PUBLISHING LTD
ASTRONOMICAL JOURNAL, 2017年07月, ［査読有り］

The Evidence of Radio Polarization Induced by the Radiative Grain Alignment and Self-scattering of Dust Grains in a Protoplanetary Disk
Akimasa Kataoka; Takashi Tsukagoshi; Adriana Pohl; Takayuki Muto; Hiroshi Nagai; Ian W. Stephens; Kohji Tomisaka; Munetake Momose, The mechanisms causing millimeter-wave polarization in protoplanetary disks are under debate. To disentangle the polarization mechanisms, we observe the protoplanetary disk around HL Tau at 3.1mm with the Atacama Large Millimeter/submillimeter Array (ALMA), which had the polarization detected with CARMA at 1.3 mm. We successfully detect the ring-like azimuthal polarized emission at 3.1 mm. This indicates that dust grains are aligned with the major axis being in the azimuthal direction, which is consistent with the theory of radiative alignment of elongated dust grains, where the major axis of dust grains is perpendicular to the radiation flux. Furthermore, the morphology of the polarization vectors at 3.1mm is completely different from those at 1.3 mm. We interpret the polarization at 3.1mm to be dominated by the grain alignment with the radiative flux producing azimuthal polarization vectors, while the self-scattering dominates at 1.3mm and produces the polarization vectors parallel to the minor axis of the disk. By modeling the total polarization fraction with a single grain population model, the maximum grain size is constrained to be 100 mm, which is smaller than the previous predictions based on the spectral index between ALMA at 3mm and the Very Large Array at 7 mm., IOP PUBLISHING LTD
ASTROPHYSICAL JOURNAL LETTERS, 2017年07月, ［査読有り］

Planet Formation in AB Aurigae: Imaging of the Inner Gaseous Spirals Observed inside the Dust Cavity
Ya-Wen Tang; Stephane Guilloteau; Anne Dutrey; Takayuki Muto; Bo-Ting Shen; Pin-Gao Gu; Shu-ichiro Inutsuka; Munetake Momose; Vincent Pietu; Misato Fukagawa; Edwige Chapillon; Paul T. P. Ho; Emmanuel di Folco; Stuartt Corder; Nagayoshi Ohashi; Jun Hashimoto, We report the results of ALMA observations of a protoplanetary disk surrounding the Herbig Ae star AB Aurigae. We obtained high-resolution (0.'' 1; 14 au) images in (CO)-C-12 J = 2 - 1 emission and in the dust continuum at the wavelength of 1.3 mm. The continuum emission is detected at the center and at the ring with a radius (r) of similar to 120 au. The CO emission is dominated by two prominent spirals within the dust ring. These spirals are trailing and appear to be about 4 times brighter than their surrounding medium. Their kinematics is consistent with Keplerian rotation at an inclination of 23 degrees. The apparent two-arm-spiral pattern is best explained by tidal disturbances created by an unseen companion located at r of 60-80 au, with dust confined in the pressure bumps created outside this companion orbit. An additional companion at r of 30 au, coinciding with the peak CO brightness and a large pitch angle of the spiral, would help to explain the overall emptiness of the cavity. Alternative mechanisms to excite the spirals are discussed. The origin of the large pitch angle detected here remains puzzling., IOP PUBLISHING LTD
ASTROPHYSICAL JOURNAL, 2017年05月, ［査読有り］

Detailed modeling of dust distribution in the disk of HD 142527
Kang-Lou Soon; Tomoyuki Hanawa; Takayuki Muto; Takashi Tsukagoshi; Munetake Momose, We investigate the dust distribution in the crescent disk around HD 142527 based on the continuum emission at 890 mu m obtained by ALMA Cycle 0. The map is divided into 18 azimuthal sectors, and the radial intensity profile in each sector is reproduced with a two-dimensional diskmodel. Ourmodel takes account of scattering and inclination of the disk as well as the azimuthal dependence in intensity. When the dust is assumed to have the conventional composition and a maximum size of 1mm, the northwestern region (PA = 291 degrees-351 degrees) cannot be reproduced. This is because the model intensity becomes insensitive to the increase in surface density due to heavy self-scattering, reaching its ceilingmuch lower than the observed intensity. The ceiling depends on the position angle, PA. When the scattering opacity is reduced by a factor of 10, the intensity distribution is reproduced successfully in all the sectors, including those in the northwestern region. The best-fitting model parameters depend little on the scattering opacity in the southern region where the disk is optically thin. The contrast ratio of dust surface densities along PA is derived to be about 40, much smaller than the value in the case of conventional opacities (70-130). These results strongly suggest that the albedo is lower than that considered for some reason, at least in the northwestern region., OXFORD UNIV PRESS
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 2017年04月, ［査読有り］

Detection of Submillimeter-wave [CI] Emission in Gaseous Debris Disks of 49 Ceti and beta Pictoris
Aya E. Higuchi; Aki Sato; Takashi Tsukagoshi; Nami Sakai; Kazunari Iwasaki; Munetake Momose; Hiroshi Kobayashi; Daisuke Ishihara; Sakae Watanabe; Hidehiro Kaneda; Satoshi Yamamoto, We have detected [C I] P-3(1)-P-3(0) emissions in the gaseous debris disks of 49 Ceti and beta Pictoris with the 10 m telescope of the Atacama Submillimeter Telescope Experiment, which is the first detection of such emissions. The line profiles of [C I] are found to resemble those of CO(J = 3-2) observed with the same telescope and the Atacama Large Millimeter/submillimeter Array. This result suggests that atomic carbon (C) coexists with CO in the debris disks. and is likely formed by the photodissociation of CO. Assuming an optically thin [C I] emission with the excitation temperature ranging from 30 to 100. K, the column density of C is evaluated to be (2.2 +/- 0.2). x. 10(17) and (2.5 +/- 0.7). x. 10(16). cm(-2) for 49 Ceti and beta Pictoris, respectively. The C/CO column density ratio is thus derived to be 54 +/- 19 and 69 +/- 42 for 49 Ceti and beta Pictoris, respectively. These ratios are higher than those of molecular clouds and diffuse clouds by an order of magnitude. The unusually high ratios of C to CO are likely attributed to a lack of H-2 molecules needed to reproduce CO molecules efficiently from C. This result implies a small number of H-2 molecules in the gas disk,. i.e., there is an appreciable contribution of secondary gas from dust grains., IOP PUBLISHING LTD
ASTROPHYSICAL JOURNAL LETTERS, 2017年04月, ［査読有り］

Detection of submillimeter-wave [C I]emission in gaseous debris disks of 49 Ceti and β Pictoris
Higuchi, A.E.; Sato, A.; Tsukagoshi, T.; Sakai, N.; Iwasaki, K.; Momose, M.; Kobayashi, H.; Ishihara, D.; Kaneda, H.; Yamamoto, S., Proceedings of the International Astronomical Union
Proceedings of the International Astronomical Union, 2017年

Radial decoupling of small and large dust grains in the transitional disk RX J1615.3-3255
Robin Kooistra; Inga Kamp; Misato Fukagawa; Franois Menard; Munetake Momose; Takashi Tsukagoshi; Tomoyuki Kudo; Nobuhiko Kusakabe; Jun Hashimoto; Lyu Abe; Wolfgang Brandner; Timothy D. Brandt; Joseph C. Carson; Sebastian E. Egner; Markus Feldt; Miwa Goto; Carol A. Grady; Olivier Guyon; Yutaka Hayano; Masahiko Hayashi; Saeko S. Hayashi; Thomas Henning; Klaus W. Hodapp; Miki Ishii; Masanori Iye; Markus Janson; Ryo Kandori; Gillian R. Knapp; Masayuki Kuzuhara; Jungmi Kwon; Taro Matsuo; Michael W. McElwain; Shoken Miyama; Jun-Ichi Morino; Amaya Moro-Martin; Tetsuo Nishimura; Tae-Soo Pyo; Eugene Serabyn; Takuya Suenaga; Hiroshi Suto; Ryuji Suzuki; Yasuhiro H. Takahashi; Michihiro Takami; Naruhisa Takato; Hiroshi Terada; Christian Thalmann; Daigo Tomono; Edwin L. Turner; Makoto Watanabe; John Wisniewski; Toru Yamada; Hideki Takami; Tomonori Usuda; Motohide Tamura; Thayne Currie; Eiji Akiyama; Satoshi Mayama; Katherine B. Follette; Takao Nakagawa, We present H-band (1.6 mu m) scattered light observations of the transitional disk RX J1615.3-3255, located in the similar to 1 Myr old Lupus association. From a polarized intensity image, taken with the HiCIAO instrument of the Subaru Telescope, we deduce the position angle and the inclination angle of the disk. The disk is found to extend out to 68 +/- 12 AU in scattered light and no clear structure is observed. Our inner working angle of 24 AU does not allow us to detect a central decrease in intensity similar to that seen at 30 AU in the 880 mu m continuum observations. We compare the observations with multiple disk models based on the spectral energy distribution (SED) and submm interferometry and find that an inner rim of the outer disk at 30 AU containing small silicate grains produces a polarized intensity signal which is an order of magnitude larger than observed. We show that a model in which the small dust grains extend smoothly into the cavity found for large grains is closer to the actual H-band observations. A comparison of models with di ff erent dust size distributions suggests that the dust in the disk might have undergone significant processing compared to the interstellar medium., EDP SCIENCES S A
ASTRONOMY & ASTROPHYSICS, 2017年01月, ［査読有り］

SPIRAL STRUCTURE AND DIFFERENTIAL DUST SIZE DISTRIBUTION IN THE LkH alpha 330 DISK
Eiji Akiyama; Jun Hashimoto; Hauyu Baobabu Liu; Jennifer I-Hsiu Li; Michael Bonnefoy; Ruobing Dong; Yasuhiro Hasegawa; Thomas Henning; Michael L. Sitko; Markus Janson; Markus Feldt; John Wisniewski; Tomoyuki Kudo; Nobuhiko Kusakabe; Takashi Tsukagoshi; Munetake Momose; Takayuki Muto; Tetsuo Taki; Masayuki Kuzuhara; Mayama Satoshi; Michihiro Takami; Nagayoshi Ohashi; Carol A. Grady; Jungmi Kwon; Christian Thalmann; Lyu Abe; Wolfgang Brandner; Timothy D. Brandt; Joseph C. Carson; Sebastian Egner; Miwa Goto; Olivier Guyon; Yutaka Hayano; Masahiko Hayashi; Saeko S. Hayashi; Klaus W. Hodapp; Miki Ishii; Masanori Iye; Gillian R. Knapp; Ryo Kandori; Taro Matsuo; Michael W. Mcelwain; Shoken Miyama; Jun-Ichi Morino; Amaya Moro-Martin; Tetsuo Nishimura; Tae-Soo Pyo; Eugene Serabyn; Takuya Suenaga; Hiroshi Suto; Ryuji Suzuki; Yasuhiro H. Takahashi; Naruhisa Takato; Hiroshi Terada; Daigo Tomono; Edwin L. Turner; Makoto Watanabe; Toru Yamada; Hideki Takami; Tomonori Usuda; Motohide Tamura, Dust trapping accelerates the coagulation of dust particles, and, thus, it represents an initial step toward the formation of planetesimals. We report H-band (1.6 mu m) linear polarimetric observations and 0.87 mm interferometric continuum observations toward a transitional disk around LkH alpha 330. As a. result, a pair of spiral arms were detected in the H-band emission, and an asymmetric (potentially arm-like) structure was detected in the 0.87 mm continuum emission. We discuss the origin of the spiral arm and the asymmetric structure. and suggest that a massive unseen planet is the most plausible explanation. The possibility of dust trapping and grain growth causing the asymmetric structure was also investigated through the opacity index (beta) by plotting the observed spectral energy distribution slope between 0.87 mm from our Submillimeter Array observation and 1.3 mm from literature. The results imply that grains are indistinguishable from interstellar medium-like dust in the east side (beta = 2.0 +/- 0.5) but are much smaller in the west side beta = 0.7(-0.4)(+0.5), indicating differential dust size distribution between the two sides of the disk. Combining the results of near-infrared and submillimeter observations, we conjecture that the spiral arms exist at the upper surface and an asymmetric structure resides in the disk interior. Future observations at centimeter wavelengths and differential polarization imaging in other bands (Y-K) with extreme AO imagers are required to understand how large dust grains form and to further explore the dust distribution in the disk., IOP PUBLISHING LTD
ASTRONOMICAL JOURNAL, 2016年12月, ［査読有り］

Submillimeter Polarization Observation of the Protoplanetary Disk around HD 142527
Kataoka; A.; Tsukagoshi; T.; Momose; M.; Nagai; H.; Muto; T.; Dullemond; C. P.; Pohl; A.; Fukagawa; M.; Shibai; H.; Hanawa; T.; & Murakawa; K., We present the polarization observations toward the circumstellar disk around HD 142527 by using Atacama Large Millimeter/submillimeter Array at the frequency of 343 GHz. The beam size is 0.'' 51 x 0.'' 44, which corresponds to the spatial resolution of similar to 71 x 62 au. The polarized intensity displays a ring-like structure with a peak located on the east side with a polarization fraction of P = 3.26 +/- 0.02%, which is different from the peak of the continuum emission from the northeast region. The polarized intensity is significantly weaker at the peak of the continuum where P = 0.220 +/- 0.010%. The polarization vectors are in the radial direction in the main ring of the polarized intensity, while there are two regions outside at the northwest and northeast areas where the vectors are in the azimuthal direction. If the polarization vectors represent the magnetic field morphology, the polarization vectors indicate the toroidal magnetic field configuration on the main ring and the poloidal fields outside. On the other hand, the flip of the polarization vectors is predicted by the self-scattering of thermal dust emission due to the change of the direction of thermal radiation flux. Therefore, we conclude that self-scattering of thermal dust emission plays a major role in producing polarization at millimeter wavelengths in this protoplanetary disk. Also, this puts a constraint on the maximum grain size to be approximately 150 mu m if we assume compact spherical dust grains., IOP PUBLISHING LTD
The Astrophysical Journal Letters, 2016年11月, ［査読有り］

Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. II. Internal proper motion measurement in G006.79-00.25
Sugiyama; K.; Fujisawa; K.; Hachisuka; K.; Yonekura; Y.; Motogi; K.; Sawada-Satoh; S.; Matsumoto; N.; Hirano; D.; Hayashi; K.; Kobayashi; H.; Kawaguchi; N.; Shibata; K. M.; Honma; M.; Hirota; T.; Murata; Y.; Doi; A.; Ogawa; H.; Kimura; K.; Niinuma; K.; Chen; X.; Xia; B.; Li; B.; Sorai; K.; Momose; M.; Saito; Y.; Takaba; H.; Omodaka; T.; Kim; K.-T.; & Shen; Z., We detected internal proper motions of the methanol maser features at 6.7 GHz in a high-mass star-forming region G006.79-00.25 with the East-Asian VLBI Network. The spatial distribution of the maser features shows an elliptical morphology. The internal proper motions of 17 methanol maser features relative to the barycenter of the features were measured. The amplitude of the internal motions ranged from 1.30 to 10.25 kms(-1). Most of the internal proper motions of the maser features seem to point counter-clockwise along the elliptical morphology of the maser features. We applied the disk model, which includes both rotating and expanding components, to the observed positions, i.o.s. velocities, and proper motions. The derived rotation, expansion, and systemic velocities are +3(-2)(+2), +6(-2)(+2), and +21(-2)(+2) kms(-1), respectively, at the radius of 1260 au on the disk with a position angle of the semi-major axis of -140 degrees. and an inclination of 60 degrees. The derived rotating motion suggests that the methanol maser emissions showing the elliptical spatial morphology possibly trace the rotating disk. The derived expanding motion might be caused by the magnetic-centrifugal wind on the disk, which was estimated on the basis of the typical magnetic field strength at emitting zones of a methanol maser., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2016年10月, ［査読有り］

The Hitachi and Takahagi 32 m radio telescopes: Upgrade of the antennas from satellite communication to radio astronomy
Yonekura; Y.; Saito; Y.; Sugiyama; K.; Soon; K. L.; Momose; M.; Yokosawa; M.; Ogawa; H.; Kimura; K.; Abe; Y.; Nishimura; A.; Hasegawa; Y.; Fujisawa; K.; Ohyama; T.; Kono; Y.; Miyamoto; Y.; Sawada-Satoh; S.; Kobayashi; H.; Kawaguchi; N.; Honma; M.; Shibata; K. M.; Sato; K.; Ueno; Y.; Jike; T.; Tamura; Y.; Hirota; T.; Miyazaki; A.; Niinuma; K.; Sorai; K.; Takaba; H.; Hachisuka; K.; Kondo; T.; Sekido; M.; Murata; Y.; Nakai; N.; & Omodaka; T., The Hitachi and Takahagi 32 m radio telescopes (former satellite communication antennas) were so upgraded as to work at 6, 8, and 22 GHz. We developed the receiver systems, IF systems, back-end systems (including samplers and recorders), and reference systems. We measured the performance of the antennas. The system temperature including the atmosphere toward the zenith, T*(sys), is measured to be similar to 30-40 K for 6 GHz and similar to 25-35 K for 8 GHz. T*(sys) for 22 GHz is measured to be similar to 40-100 K in winter and similar to 150-500K in summer seasons, respectively. The aperture efficiency is 55%-75% for Hitachi at 6 GHz and 8 GHz, and 55%-65% for Takahagi at 8 GHz. The beam sizes at 6 GHz and 8 GHz are similar to 4.'6 and similar to 3.'8, respectively. The side-lobe level is less than 3%-4% at 6 and 8 GHz. Pointing accuracy was measured to be better than similar to 0.'3 for Hitachi and similar to 0.'6 for Takahagi. We succeeded in VLBI observations in 2010 August, indicating good performance of the antenna. We started single-dish monitoring observations of 6.7 GHz methanol maser sources in 2012 December, and found several new sources showing short-term periodic variation of the flux density., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2016年10月, ［査読有り］

Constraining the Movement of the Spiral Features and the Locations of Planetary Bodies within the AB Aur System
Lomax; J. R.; Wisniewski; J. P.; Grady; C. A.; McElwain; M. W.; Hashimoto; J.; Kudo; T.; Kusakabe; N.; Okamoto; Y. K.; Fukagawa; M.; Abe; L.; Brandner; W.; Brandt; T. D.; Carson; J. C.; Currie; T. M.; Egner; S.; Feldt; M.; Goto; M.; Guyon; O.; Hayano; Y.; Hayashi; M.; Hayashi; S. S.; Henning; T.; Hodapp; K. W.; Inoue; A.; Ishii; M.; Iye; M.; Janson; M.; Kandori; R.; Knapp; G. R.; Kuzuhara; M.; Kwon; J.; Matsuo; T.; Mayama; S.; Miyama; S.; Momose; M.; Morino; J.-I.; Moro-Martin; A.; Nishimura; T.; Pyo; T.-S.; Schneider; G. H.; Serabyn; E.; Sitko; M. L.; Suenaga; T.; Suto; H.; Suzuki; R.; Takahashi; Y. H.; Takami; M.; Takato; N.; Terada; H.; Thalmann; C.; Tomono; D.; Turner; E. L.; Watanabe; M.; Yamada; T.; Takami; H.; Usuda; T.; & Tamura; M., We present a new analysis of multi-epoch, H-band, scattered light images of the AB Aur system. We use a Monte Carlo radiative transfer code to simultaneously model the system's spectral energy distribution (SED) and H-band polarized intensity (PI) imagery. We find that a disk-dominated model, as opposed to one that is envelope-dominated, can plausibly reproduce AB Aur's SED and near-IR imagery. This is consistent with previous modeling attempts presented in the literature and supports the idea that at least a subset of AB Aur's spirals originate within the disk. In light of this, we also analyzed the movement of spiral structures in multi-epoch H-band total light and PI imagery of the disk. We detect no significant rotation or change in spatial location of the spiral structures in these data, which span a 5.8-year baseline. If such structures are caused by disk-planet interactions, the lack of observed rotation constrains the location of the orbit of planetary perturbers to be >47 au., IOP PUBLISHING LTD
The Astrophysical Journal, 2016年09月, ［査読有り］

Extreme asymmetry in the polarized disk of V1247 Orionis
Ohta; Y.; Fukagawa; M.; Sitko; M. L.; Muto; T.; Kraus; S.; Grady; C. A.; Wisniewski; J. P.; Swearingen; J. R.; Shibai; H.; Sumi; T.; Hashimoto; J.; Kudo; T.; Kusakabe; N.; Momose; M.; Okamoto; Y.; Kotani; T.; Takami; M.; Currie; T.; Thalmann; C.; Janson; M.; Akiyama; E.; Follette; K. B.; Mayama; S.; Abe; L.; Brandner; W.; Brandt; T. D.; Carson; J. C.; Egner; S. E.; Feldt; M.; Goto; M.; Guyon; O.; Hayano; Y.; Hayashi; M.; Hayashi; S. S.; Henning; T.; Hodapp; K. W.; Ishii; M.; Iye; M.; Kandori; R.; Knapp; G. R.; Kuzuhara; M.; Kwon; J.; Matsuo; T.; McElwain; M. W.; Miyama; S.; Morino; J.-I.; Moro-Martin; A.; Nishimura; T.; Pyo; T.-S.; Serabyn; E.; Suenaga; T.; Suto; H.; Suzuki; R.; Takahashi; Y. H.; Takami; H.; Takato; N.; Terada; H.; Tomono; D.; Turner; E. L.; Usuda; T.; Watanabe; M.; Yamada; T.; & Tamura; M., We present the first near-infrared scattered-light detection of the transitional disk around V1247 Ori, which was obtained using high-resolution polarimetric differential imaging observations with Subaru/HiCIAO. Our imaging in the H band reveals the disk morphology at separations of similar to 0.'' 14-0.'' 86 (54-330 au) from the central star. The polarized intensity image shows a remarkable arc-like structure toward the southeast of the star, whereas the fainter northwest region does not exhibit any notable features. The shape of the arm is consistent with an arc of 0.'' 28 +/- 0.'' 09 in radius (108 au from the star), although the possibility of a spiral arm with a small pitch angle cannot be excluded. V1247 Ori features an exceptionally large azimuthal contrast in scattered, polarized light; the radial peak of the southeastern arc is about three times brighter than the northwestern disk measured at the same distance from the star. Combined with the previous indication of an inhomogeneous density distribution in the gap at less than or similar to 46 au, the notable asymmetry in the outer disk suggests the presence of unseen companions and/or planet-forming processes ongoing in the arc., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2016年08月, ［査読有り］

Mass constraint for a planet in a protoplanetary disk from the gap width
Kanagawa; K. D.; Muto; T.; Tanaka; H.; Tanigawa; T.; Takeuchi; T.; Tsukagoshi; T.; & Momose; M., A giant planet creates a gap in a protoplanetary disk, which might explain the observed gaps in protoplanetary disks. The width and depth of the gaps depend on the planet mass and disk properties. We have performed two-dimensional hydrodynamic simulations for various planet masses, disk aspect ratios, and viscosities, to obtain an empirical formula for the gap width. The gap width is proportional to the square root of the planet mass, -3/4 the power of the disk aspect ratio and -1/4 the power of the viscosity. This empirical formula enables us to estimate the mass of a planet embedded in the disk from the width of an observed gap. We have applied the empirical formula for the gap width to the disk around HL Tau, assuming that each gap observed by the Atacama Large Millimeter/submillimeter Array (ALMA) observations is produced by planets, and discussed the planet masses within the gaps. The estimate of planet masses from the gap widths is less affected by the observational resolution and dust filtration than that by the gap depth., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2016年06月, ［査読有り］

Sintering-induced Dust Ring Formation in Protoplanetary Disks: Application to the HL Tau Disk
Okuzumi; S.; Momose; M.; Sirono; S.-i.; Kobayashi; H.; & Tanaka; H., The latest observation of HL Tau by ALMA revealed spectacular concentric dust rings in its circumstellar disk. We attempt to explain the multiple ring structure as a consequence of aggregate sintering. Sintering is known to reduce the sticking efficiency of dust aggregates and occurs at temperatures slightly below the sublimation point of the constituent material. We present a dust growth model that incorporates sintering and use it to simulate global dust evolution due to sintering, coagulation, fragmentation, and radial inward drift in a modeled HL Tau disk. We show that aggregates consisting of multiple species of volatile ices experience sintering, collisionally disrupt, and pile up at multiple locations slightly outside the snow lines of the volatiles. At wavelengths of 0.87-1.3 mm, these sintering zones appear as bright, optically thick rings with a spectral slope of approximate to 2, whereas the non-sintering zones appear as darker, optically thinner rings of a spectral slope of approximate to 2.3-2.5. The observational features of the sintering and non-sintering zones are consistent with those of the major bright and dark rings found in the HL Tau disk, respectively. Radial pileup and vertical settling occur simultaneously if disk turbulence is weak and if monomers constituting the aggregates are similar to 1 mu m in radius. For the radial gas temperature profile of T = 310(r/1 au)(-0.57) K, our model perfectly reproduces the brightness temperatures of the optically thick bright rings and reproduces their orbital distances to an accuracy of less than or similar to 30%., IOP PUBLISHING LTD
The Astrophysical Journal, 2016年04月, ［査読有り］

Grain Size Constraints on HL Tau with Polarization Signature
Kataoka; A.; Muto; T.; Momose; M.; Tsukagoshi; T.; & Dullemond; C. P., The millimeter-wave polarization of the protoplanetary disk around HL Tau has been interpreted as the emission from elongated dust grains aligned with the magnetic field in the disk. However, the self-scattering of thermal dust emission may also explain the observed millimeter-wave polarization. In this paper, we report a modeling of the millimeter-wave polarization of the HL Tau disk with the self-polarization. Dust grains are assumed to be spherical and to have a power-law size distribution. We change the maximum grain size with a fixed dust composition in a fixed disk model to find the grain size to reproduce the observed signature. We find that the direction of the polarization vectors and the polarization degree can be explained with the self-scattering. Moreover, the polarization degree can be explained only if the maximum grain size is similar to 150 mu m. The obtained grain size from the polarization is different from that which has been previously expected from the spectral index of the dust opacity coefficient (a millimeter or larger) if the emission is optically thin. We discuss that porous dust aggregates may solve the inconsistency of the maximum grain size between the two constraints., IOP PUBLISHING LTD
The Astrophysical Journal, 2016年03月, ［査読有り］

Spectral-line Survey at Millimeter and Submillimeter Wavelengths toward an Outflow-shocked Region, OMC 2-FIR 4
Shimajiri, Yoshito; Sakai, Takeshi; Kitamura, Yoshimi; Tsukagoshi, Takashi; Saito, Masao; Nakamura, Fumitaka; Momose, Munetake; Takakuwa, Shigehisa; Yamaguchi, Takahiro; Sakai, Nami; Yamamoto, Satoshi; Kawabe, Ryohei, We performed the first spectral line survey at 82-106 GHz and 335-355 GHz toward the outflow-shocked region OMC 2-FIR 4, the outflow driving source FIR 3, and the northern outflow lobe FIR 3N. We detected 120 lines of 20 molecular species. The line profiles can be classified into two types: one type is a single Gaussian component with a narrow (<3 km s^-1) width, and the other type is two Gaussian components with narrow and wide (>3 km s^-1) widths. The narrow components for most of the lines are detected at all positions, suggesting that they trace the ambient dense gas. For CO, CS, HCN, and HCO⁺, the wide components are detected at all positions, suggesting an outflow origin. The wide components of C³⁴S, SO, SiO, H¹³CN, HC¹⁵N, { { {H } } }₂¹³CO, H₂CS, HC₃N, and CH₃OH are only detected at FIR 4, suggesting an origin as outflow-shocked gas. The rotation diagram analysis revealed that the narrow components of C₂H and H¹³CO⁺ show low temperatures of 12.5 ± 1.4 K, while the wide components show high temperatures of 20-70 K. This supports our interpretation that the wide components trace the outflow and/or outflow-shocked gas. We compared the observed molecular abundances relative to H¹³CO⁺ with those of the outflow-shocked region L 1157 B1 and the hot corino IRAS 16293-2422. Although we cannot exclude the possibility that the chemical enrichment in FIR 4 is caused by hot-core chemistry, the chemical compositions in FIR 4 are more similar to those in L 1157 B1 than those in IRAS 16293-2422....
The Astrophysical Journal Supplement Series, 2015年12月, ［査読有り］

Z45: A new 45-GHz band dual-polarization HEMT receiver for the NRO 45-m radio telescope
Nakamura; F.; Ogawa; H.; Yonekura; Y.; Kimura; K.; Okada; N.; Kozu; M.; Hasegawa; Y.; Tokuda; K.; Ochiai; T.; Mizuno; I.; Dobashi; K.; Shimoikura; T.; Kameno; S.; Taniguchi; K.; Shinnaga; H.; Takano; S.; Kawabe; R.; Nakajima; T.; Iono; D.; Kuno; N.; Onishi; T.; Momose; M.; & Yamamoto; S., We developed a dual-linear-polarization HEMT (High Electron Mobility Transistor) amplifier receiver system of the 45-GHz band (hereafter Z45), and installed it in the Nobeyama 45-m radio telescope. The receiver system is designed to conduct polarization observations by taking the cross-correlation of two linearly polarized components, from which we process full Stokes spectroscopy. We aim to measure themagnetic field strength through the Zeeman effect of the emission line of CCS (JN = 43-32) toward pre-protostellar cores. A linear-polarization receiver system has a smaller contribution of instrumental polarization components to the Stokes V spectra than that of the circular polarization system, so that it is easier to obtain the Stokes V spectra. The receiver has an RF frequency of 42-46 GHz and an intermediate frequency (IF) band of 4-8 GHz. The typical noise temperature is about 50 K, and the system noise temperature ranges from 100 to 150 K over the frequency of 42-46 GHz. The receiver system is connected to two spectrometers, SAM45 and PolariS. SAM45 is a highly flexible FX-type digital spectrometer with a finest frequency resolution of 3.81 kHz. PolariS is a newly developed digital spectrometer with a finest frequency resolution of 60 Hz, and which has a capability to process the full-Stokes spectroscopy. The half-power beam width (HPBW) was measured to be 37 '' at 43 GHz. The main beam efficiency of the Gaussian main beam was derived to be 0.72 at 43 GHz. The SiO maser observations show that the beam pattern is reasonably round at about 10% of the peak intensity and the side-lobe level was less than 3% of the peak intensity. Finally, we present some examples of astronomical observations using Z45., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2015年12月, ［査読有り］

Significant gas-to-dust ratio asymmetry and variation in the disk of HD 142527 and the indication of gas depletion
Muto; T.; Tsukagoshi; T.; Momose; M.; Hanawa; T.; Nomura; H.; Fukagawa; M.; Saigo; K.; Kataoka; A.; Kitamura; Y.; Takahashi; S. Z.; Inutsuka; S.-i.; Takeuchi; T.; Kobayashi; H.; Akiyama; E.; Honda; M.; Fujiwara; H.; & Shibai; H., We investigate the dust and gas distribution in the disk around HD 142527 based on ALMA observations of dust continuum emissions, (CO)-C-13 J = 3-2 and (CO)-O-18 J = 3-2. The disk shows strong azimuthal asymmetry in the dust continuum emission, while gas emission is more symmetric. In this paper, we investigate how gas and dust are distributed in the dust-bright northern part of the disk and in the dust-faint southern part. We construct two axisymmetric disk models. One reproduces the radial profiles of the continuum and the velocity moments 0 and 1 of CO lines in the north, and the other reproduces those in the south. We have found that the dust is concentrated in a narrow ring of similar to 50 au width (in FWHM; omega(d) = 30 au in our parameter definition), located at similar to 170-200 au from the central star. The dust particles are strongly concentrated in the north. We have found that the dust surface density contrast between the north and the south amounts to similar to 70. Compared to the dust, the gas distribution is more extended in the radial direction. We find that the gas component extends at least from similar to 100 au to similar to 250 au from the central star, and there should also be tenuous gas remaining inside and outside of these radii. The azimuthal asymmetry of gas distribution is much smaller than dust. The gas surface density differs only by a factor of similar to 3-10 between the north and south. Hence, the gas-to-dust ratio strongly depends on the location of the disk: similar to 30 at the location of the peak of dust distribution in the south and similar to 3 at the location of the peak of dust distribution in the north. Despite large uncertainties, we infer that the overall gas-to-dust ratio is similar to 10-30, indicating that the gas depletion may already have been under way., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2015年12月, ［査読有り］

Detailed structure of the outer disk around HD 169142 with polarized light in H-band
Momose; M.; Morita; A.; Fukagawa; M.; Muto; T.; Takeuchi; T.; Hashimoto; J.; Honda; M.; Kudo; T.; Okamoto; Y. K.; Kanagawa; K. D.; Tanaka; H.; Grady; C. A.; Sitko; M. L.; Akiyama; E.; Currie; T.; Follette; K. B.; Mayama; S.; Kusakabe; N.; Abe; L.; Brandner; W.; Brandt; T. D.; Carson; J. C.; Egner; S.; Feldt; M.; Goto; M.; Guyon; O.; Hayano; Y.; Hayashi; M.; Hayashi; S. S.; Henning; T.; Hodapp; K. W.; Ishii; M.; Iye; M.; Janson; M.; Kandori; R.; Knapp; G. R.; Kuzuhara; M.; Kwon; J.; Matsuo; T.; McElwain; M. W.; Miyama; S.; Morino; J.-I.; Moro-Martin; A.; Nishimura; T.; Pyo; T.-S.; Serabyn; E.; Suenaga; T.; Suto; H.; Suzuki; R.; Takahashi; Y. H.; Takami; M.; Takato; N.; Terada; H.; Thalmann; C.; Tomono; D.; Turner; E. L.; Watanabe; M.; Wisniewski; J.; Yamada; T.; Takami; H.; Usuda; T.; & Tamura; M., 筆頭著者, Coronagraphic imagery of the circumstellar disk around HD 169142 in H-band polarized intensity (PI) with Subaru/HiCIAO is presented. The emission scattered by dust particles at the disk surface in 0".2 <= r <= 1".2, or 29 <= r <= 174 AU, is successfully detected. The azimuthally-averaged radial profile of the PI shows a double power-law distribution, in which the PIs in r=29-52 AU and r=81.2-145 AU respectively show r(-3)-dependence. These two power-law regions are connected smoothly with a transition zone (TZ), exhibiting an apparent gap in r=40-70 AU. The PI in the inner power-law region shows a deep minimum whose location seems to coincide with the point source at lambda = 7 mm. This can be regarded as another sign of a protoplanet in TZ. The observed radial profile of the PI is reproduced by a minimally flaring disk with an irregular surface density distribution or with an irregular temperature distribution or with the combination of both. The depletion factor of surface density in the inner power-law region (r<50 AU) is derived to be >= 0.16 from a simple model calculation. The obtained PI image also shows small scale asymmetries in the outer power-law region. Possible origins for these asymmetries include corrugation of the scattering surface in the outer region, and shadowing effect by a puffed up structure in the inner power-law region., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2015年10月, ［査読有り］

Flux Monitoring of 6.7 GHz Methanol Maser to Systematically Research Periodic Variations Using the Hitachi 32-m
Sugiyama, Koichiro; Yonekura, Yoshinori; Motogi, Kazuhito; Saito, Yu; Fujisawa, Kenta; Ishii, Shota; Momose, Munetake; Honma, Mareki; Tazaki, Fumie; Tanaka, Kei E. I.; Hosokawa, Takashi; Uchiyama, Mizuho; Inayoshi, Kohei, We have initiated single-dish monitoring observations of ~400 methanol maser sources at 6.7 GHz using the Hitachi 32-m radio telescope from December 2012 to systematically research periodic flux variations, which are observed in some methanol maser sources associated with high-mass (proto-)stars. In our monitoring, we have made daily monitoring, so that each source has been observed every nine days with an integration time of 5 min (typical detection sensitivities of 0.9 Jy). The monitoring observations help us statistically understand periodic flux variations with a period longer than 50 days. As an initial result, we present a new detection of periodic flux variations in the 6.7 GHz methanol maser source G036.70+00.09. The period of the flux variations is ~53 days (~0.019 cycles), and seems to be stable over 9 cycles, at least until the middle of August 2014....
Publication of Korean Astronomical Society, 2015年09月, ［査読有り］

Millimeter-wave Polarization of Protoplanetary Disks due to Dust Scattering
Kataoka; A.; Muto; T.; Momose; M.; Tsukagoshi; T.; Fukagawa; M.; Shibai; H.; Hanawa; T.; Murakawa; K.; & Dullemond; C. P., We present a new method to constrain the grain size in protoplanetary disks with polarization observations at millimeter wavelengths. If dust grains are grown to the size comparable to the wavelengths, the dust grains are expected to have a large scattering opacity, and thus the continuum emission is expected to be polarized due to self-scattering. We perform 3D radiative transfer calculations to estimate the polarization degree for the protoplanetary disks having radial Gaussian-like dust surface density distributions, which have been recently discovered. The maximum grain size is set to be 100 mu m and the observing wavelength to be 870 mu m. We find that the polarization degree is as high as 2.5% with a subarcsec spatial resolution, which is likely to be detected with near-future ALMA observations. The emission is polarized due to scattering of anisotropic continuum emission. The map of the polarization degree shows a double-peaked distribution, and the polarization vectors are in the radial direction in the inner ring and in the azimuthal direction in the outer ring. We also find the wavelength dependence of the polarization degree: the polarization degree is the highest if dust grains have a maximum size of a(max) similar to lambda/2 pi, where lambda is the observing wavelength. Hence, multi-wave and spatially resolved polarization observations toward protoplanetary disks enable us to put a constraint on the grain size. The constraint on the grain size from polarization observations is independent of or may be even stronger than that from the opacity index., IOP PUBLISHING LTD
The Astrophysical Journal, 2015年08月, ［査読有り］

Mass Estimates of a Giant Planet in a Protoplanetary Disk from the Gap Structures
Kanagawa; K. D.; Muto; T.; Tanaka; H.; Tanigawa; T.; Takeuchi; T.; Tsukagoshi; T.; & Momose; M., A giant planet embedded in a protoplanetary disk forms a gap. An analytic relationship among the gap depth, planet mass M-p, disk aspect ratio h(p), and viscosity alpha has been found recently, and the gap depth can be written in terms of a single parameter K = (M-p/M-*)(2)h(p)(-5)alpha(-1). We discuss how observed gap features can be used to constrain the disk and/or planet parameters based on the analytic formula for the gap depth. The constraint on the disk aspect ratio is critical in determining the planet mass so the combination of the observations of the temperature and the image can provide a constraint on the planet mass. We apply the formula for the gap depth to observations of HL Tau and HD 169142. In the case of HL Tau, we propose that a planet with greater than or similar to 0.3M(J) is responsible for the observed gap at 30 AU from the central star based on the estimate that the gap depth is less than or similar to 1/3. In the case of HD 169142, the planet mass that causes the gap structure recently found by VLA is greater than or similar to 0.4M(J). We also argue that the spiral structure, if observed, can be used to estimate the lower limit of the disk aspect ratio and the planet mass., IOP PUBLISHING LTD
The Astrophysical Journal Letters, 2015年06月, ［査読有り］

Discovery of a Disk Gap Candidate at 20 AU in TW Hydrae
Akiyama; E.; Muto; T.; Kusakabe; N.; Kataoka; A.; Hashimoto; J.; Tsukagoshi; T.; Kwon; J.; Kudo; T.; Kandori; R.; Grady; C. A.; Takami; M.; Janson; M.; Kuzuhara; M.; Henning; T.; Sitko; M. L.; Carson; J. C.; Mayama; S.; Currie; T.; Thalmann; C.; Wisniewski; J.; Momose; M.; Ohashi; N.; Abe; L.; Brandner; W.; Brandt; T. D.; Egner; S.; Feldt; M.; Goto; M.; Guyon; O.; Hayano; Y.; Hayashi; M.; Hayashi; S.; Hodapp; K. W.; Ishi; M.; Iye; M.; Knapp; G. R.; Matsuo; T.; Mcelwain; M. W.; Miyama; S.; Morino; J.-I.; Moro-Martin; A.; Nishimura; T.; Pyo; T.-S.; Serabyn; G.; Suenaga; T.; Suto; H.; Suzuki; R.; Takahashi; Y. H.; Takato; N.; Terada; H.; Tomono; D.; Turner; E. L.; Watanabe; M.; Yamada; T.; Takami; H.; Usuda; T.; & Tamura; M., We present a new Subaru/HiCIAO high-contrast H-band polarized intensity (PI) image of a nearby transitional disk associated with TW Hydrae. The scattered light from the disk was detected from 0 ''.2 to 1 ''.5 (11-81 AU) and the PI image shows a clear axisymmetric depression in PI at similar to 0 ''.4 (similar to 20 AU) from the central star, similar to the similar to 80 AU gap previously reported from Hubble Space Telescope images. The azimuthal PI profile also shows that the disk beyond 0 ''.2 is almost axisymmetric. We discuss two possible scenarios explaining the origin of the PI depression: (1) a gap structure may exist at similar to 20 AU from the central star because of a shallow slope seen in the PI profile, and (2) grain growth may be occurring in the inner region of the disk. Multi-band observations at near-infrared and millimeter/submillimeter wavelengths play a complementary role in investigating dust opacity and may help reveal the origin of the gap more precisely., IOP PUBLISHING LTD
The Astrophysical Journal Letters, 2015年04月, ［査読有り］

First Detection of [C I] $^{3}$P$_{1}$-$^{3}$P$_{0}$ Emission from a Protoplanetary Disk
Tsukagoshi; T.; Momose; M.; Saito; M.; Kitamura; Y.; Shimajiri; Y.; & Kawabe; R., We performed single point [C I] P-3(1)-P-3(0) and CO J = 4-3 observations toward three T Tauri stars (TTSs), DM Tau, LkCa 15, and TW Hya, using the Atacama Large Millimeter/submillimeter Array Band 8 qualification model receiver installed on the Atacama Submillimeter Telescope Experiment. Two protostars (PSs) in the Taurus L1551 region, L1551 IRS 5 and HL Tau, were also observed. We successfully detected [C I] emission from the protoplanetary disk around DM Tau as well as the protostellar targets. The spectral profile of the [C I] emission from the protoplanetary disk is marginally single-peaked, suggesting that atomic carbon (C) extends toward the outermost disk. The detected [C I] emission is optically thin and the column densities of C are estimated to be less than or similar to 10(16) and similar to 10(17) cm(-2) for the TTS targets and the PSs, respectively. We found a clear difference in the total mass ratio of C to dust, M(C)/M(dust), between the TTSs and protostellar targets; the M(C)/M(dust) ratio of the TTSs is one order of magnitude smaller than that of the PSs. The decrease of the estimated M(C)/M(dust) ratios for the disk sources is consistent with a theoretical prediction that the atomic C can survive only in the near surface layer of the disk and C+/C/CO transition occurs deeper into the disk midplane., IOP PUBLISHING LTD
The Astrophysical Journal Letters, 2015年03月, ［査読有り］

Catalog of Dense Cores in the Orion A Giant Molecular Cloud
Shimajiri; Y.; Kitamura; Y.; Nakamura; F.; Momose; M.; Saito; M.; Tsukagoshi; T.; Hiramatsu; M.; Shimoikura; T.; Dobashi; K.; Hara; C.; & Kawabe; R., We present Orion A giant molecular cloud core catalogs, which are based on a 1.1 mm map with an angular resolution of 36 '' (similar to 0.07 pc) and (CO)-O-18 (J = 1-0) data with an angular resolution of 26.4 '' (similar to 0.05 pc). We have cataloged 619 dust cores in the 1.1 mm map using the Clumpfind method. The ranges of the radius, mass, and density of these cores are estimated to be 0.01-0.20 pc, 0.6-1.2 x 10(2) M-circle dot, and 0.3 x 10(4)-9.2 x 10(6) cm(-3), respectively. We have identified 235 cores from the (CO)-O-18 data. The ranges of the radius, velocity width, LTE mass, and density are 0.13-0.34 pc, 0.31-1.31 km s(-1), 1.0-61.8 M-circle dot, and (0.8-17.5) x 10(3) cm(-3), respectively. From the comparison of the spatial distributions between the dust and (CO)-O-18 cores, four types of spatial relations were revealed: (1) the peak positions of the dust and (CO)-O-18 cores agree with each other (32.4% of the (CO)-O-18 cores), (2) two or more (CO)-O-18 cores are distributed around the peak position of one dust core (10.8% of the (CO)-O-18 cores), (3) 56.8% of the (CO)-O-18 cores are not associated with any dust cores, and (4) 69.3% of the dust cores are not associated with any (CO)-O-18 cores. The data sets and analysis are public., IOP PUBLISHING LTD
The Astrophysical Journal Supplement Series, 2015年03月, ［査読有り］

The outer disks of Herbig stars from the UV to NIR
C. Grady; M. Fukagawa; Y. Maruta; Y. Ohta; J. Wisniewski; J. Hashimoto; Y. Okamoto; M. Momose; T. Currie; M. McElwain; T. Muto; T. Kotani; N. Kusakabe; M. Feldt; M. Sitko; K. Follette; M. Bonnefoy; T. Henning; M. Takami; J. Karr; J. Kwon; T. Kudo; L. Abe; W. Brandner; T. Brandt; J. Carson; S. Egner; M. Goto; O. Guyon; Y. Hayano; M. Hayashi; S. Hayashi; K. Hodapp; M. Ishii; M. Iye; M. Janson; R. Kandori; G. Knapp; M. Kuzuhara; T. Matsuo; S. Miyama; J. -I. Morino; A. Moro-Martin; T. Nishimura; T. -S. Pyo; E. Serabyn; T. Suenaga; H. Suto; R. Suzuki; Y. H. Takahashi; N. Takato; H. Terada; C. Thalmann; D. Tomono; E. L. Turner; M. Watanabe; T. Yamada; H. Takami; T. Usuda; M. Tamura, Spatially-resolved imaging of Herbig stars and related objects began with HST, but intensified with commissioning of high-contrast imagers on 8-m class telescopes. The bulk of the data taken from the ground have been polarized intensity imagery at H-band, with the majority of the sources observed as part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey. Sufficiently many systems have been imaged that we discuss disk properties in scattered, polarized light in terms of groups defined by the IR spectral energy distribution. We find novel phenomena in many of the disks, including spiral density waves, and discuss the disks in terms of clearing mechanisms. Some of the disks have sufficient data to map the dust and gas components, including water ice dissociation products., SPRINGER
ASTROPHYSICS AND SPACE SCIENCE, 2015年02月, ［査読有り］

Cluster Formation Triggered by Filament Collisions in Serpens South
Fumitka Nakamura; Tomohiro Tanaka; Yuya Awazu; Yoshito Shimajiri; Koji Sugitani; Ryohei Kawabe; Hiroyuki Nishitani; Kazuhito Dobashi; Tomomi Shimoikura; Yoshinori Yonekura; Izumi Mizuno; Kimihiko Kimura; Kazuki Tokuda; Minato Kozu; Nozomi Okada; Yutaka Hasegawa; Hideo Ogawa; Seiji Kameno; Hiroko Shinnaga; Munetake Momose; Taku Nakajima; Toshikazu Onishi; Hiroyuki Maezawa; Tomoya Hirota; Shuro Takano; Daisuke Iono; Nario Kuno; Satoshi Yamamoto, Serpens South is a nearby infrared dark cloud (IRDC), consisting of several filamentary ridges, some of which fragment into dense clumps. On the basis of CCS (J(N) = 4(3) - 3(2)) observations, we investigated the kinematics and chemical evolution of these filamentary ridges. We find that CCS is extremely abundant along the main filament. We emphasize that Serpens South IRDC is the first cluster-forming region with extremely-strong CCS emission. We identify 6 ridges from the Herschel column density map. These ridges appear to converge toward the protocluster clump, suggesting that the collisions of these ridges may have triggered cluster formation. The collisions presumably happened within the last few x10(5) yr because the chemical evolution calculation indicates that CCS is abundant only in the first few x10(5) yr., ASTRONOMICAL SOC PACIFIC
REVOLUTION IN ASTRONOMY WITH ALMA: THE THIRD YEAR, 2015年

SEEDS -- Direct Imaging Survey for Exoplanets and Disks
Helminiak, K. G; Kuzuhara, M; Kudo, T; Tamura, M; Usuda, T; Hashimoto, J; Matsuo, T; McElwain, M. W; Momose, M; Tsukagoshi, T
18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, 2015年

Gas and Dust Structures of the Protoplanetary Disk around HD 142527
Momose, M; Muto, T; Hanawa, T; Fukagawa, M; Tsukagoshi, T; Saigo, K; Kataoka, A; Nomura, H; Takeuchi, T; Akiyama, E; Ohashi, N; Fujiwara, H; Shibai, H; Kitamura, Y; Inutsuka, S; Kobayashi, H; Honda, M; Aso, Y; Takahashi, S
Revolution in Astronomy with ALMA: The Third Year, 2015年

Expected Polarization at Sub-mm Wavelengths from Lopsided Protoplanetary Disks
Kataoka, A; Muto, T; Momose, M; Tsukagoshi, T; Fukagawa, M; Shibai, H; Hanawa, T; Murakawa, K
Revolution in Astronomy with ALMA: The Third Year, 2015年

Variability of Disk Emission in Pre-main Sequence and Related Stars. III. Exploring Structural Changes in the Pre-transitional Disk in HD 169142
Wagner; K. R.; Sitko; M. L.; Grady; C. A.; Swearingen; J. R.; Champney; E. H.; Johnson; A. N.; Werren; C.; Whitney; B. A.; Russell; R. W.; Schneider; G. H.; Momose; M.; Muto; T.; Inoue; A. K.; Lauroesch; J. T.; Hornbeck; J.; Brown; A.; Fukagawa; M.; Currie; T. M.; Wisniewski; J. P.; & Woodgate; B. E., We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between similar to 1.5-10 mu m over a maximum timescale of 10 yr. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the less than or similar to 1AU region of the disk. Through analysis of the Pa beta and Br gamma lines in our data we derive a mass accretion rate in 2013 May of (M)overdot approximate to (1.5-2.7) x 10-9 M-circle dot yr(-1). We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 yr of observations. We find that shifting the outer edge (r approximate to 0.3AU) of the inner disk by 0.05 AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish that the similar to 40-70 AU dark ring imaged in the NIR by Quanz et al. and Momose et al. and at 7 mm by Osorio et al. may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies., IOP PUBLISHING LTD
The Astrophysical Journal, 2015年01月, ［査読有り］

Cluster Formation Triggered by Filament Collisions in Serpens South
Nakamura; F.; Momose; M. (19th author); & 25 authors, The Serpens South infrared dark cloud consists of several filamentary ridges, some of which fragment into dense clumps. On the basis of CCS (J(N) = 4(3)-3(2)), HC3N (J = 5-4), N2H+ (J = 1-0), and SiO (J = 2-1, v = 0) observations, we investigated the kinematics and chemical evolution of these filamentary ridges. We find that CCS is extremely abundant along the main filament in the protocluster clump. We emphasize that Serpens South is the first cluster-forming region where extremely strong CCS emission is detected. The CCS-to-N2H+ abundance ratio is estimated to be about 0.5 toward the protocluster clump, whereas it is about 3 in the other parts of the main filament. We identify six dense ridges with different V-LSR. These ridges appear to converge toward the protocluster clump, suggesting that the collisions of these ridges may have triggered cluster formation. The collisions presumably happened within a few x 10(5) yr because CCS is abundant only for a short time. The short lifetime agrees with the fact that the number fraction of Class I objects, whose typical lifetime is 0.4 x 10(5) yr, is extremely high, about 70% in the protocluster clump. In the northern part, two ridges appear to have partially collided, forming a V-shape clump. In addition, we detected strong bipolar SiO emission that is due to the molecular outflow blowing out of the protostellar clump, as well as extended weak SiO emission that may originate from the filament collisions., IOP PUBLISHING LTD
The Astrophysical Journal Letters, 2014年08月, ［査読有り］

Observations of 6.7 GHz Methanol Masers with EAVN I: VLBI Images of the first Epoch of Observations
Fujisawa; K.; Momose; M. (9th author); & 27 authors, Very-long-baseline interferometry (VLBI) monitoring of the 6.7GHz methanol maser allows us to measure the internal proper motion of maser spots and therefore study the gas motion around high-mass young stellar objects. To this end, we have begun monitoring observations with the East-Asian VLBI Network. In this paper we present the results of the first epoch observation for 36 sources, including 35 VLBI images of the methanol maser. Since two independent sources were found in three images, images of 38 sources were obtained. In 34 sources, 10 or more spots were detected. The observed spatial scale of the maser distribution was from 9 to 4900 astronomical units, and the following morphological categories were observed: elliptical, arched, linear, paired, and complex. The position of the maser spot was determined with an accuracy of approximately 0.1 mas, which is sufficiently high to measure the internal proper motion from two years of monitoring observations. The VLBI observation, however, detected only approximately 20% of all maser emissions, suggesting that the remaining 80% of the total flux was spread into an undetectable extended distribution. Therefore, in addition to high-resolution observations, it is important to observe the whole structure of the maser emission including extended low-brightness structures, in order to reveal the associated site of the maser and gas motion. © 2014 The Author., Astronomical Society of Japan
Publications of the Astronomical Society of Japan, 2014年05月

High abundance ratio of 13CO to C18O toward photon-dominated regions in the Orion-A giant molecular cloud
Shimajiri; Y.; Kitamura; Y.; Saito; M.; M. Momose; Nakamura; F.; Dobashi; K.; Shimoikura; T.; Nishitani; H.; Yamabi; A.; Hara; C.; Katakura; S.; Tsukagoshi; T.; Tanaka; T.; & Kawabe; R., Aims. We derive physical properties such as the optical depths and the column densities of (CO)-C-13 and (CO)-O-18 to investigate the relationship between the far ultraviolet (FUV) radiation and the abundance ratios between (CO)-C-13 and (CO)-O-18.
Methods. We have carried out wide-field (0.4 deg(2)) observations with an angular resolution of 25.8 '' (similar to 0.05 pc) in (CO)-C-13 (J = 1-0) and (CO)-O-18 (J = 1-0) toward the Orion-A giant molecular cloud using the Nobeyama 45 m telescope in the on-the-fly mode.
Results. Overall distributions and velocity structures of the (CO)-C-13 and (CO)-O-18 emissions are similar to those of the (CO)-C-12 (J = 1-0) emission. The optical depths of the (CO)-C-13 and (CO)-O-18 emission lines are estimated to be 0.05 < tau(13CO) < 1.54 and 0.01 < tau(C18O) < 0.18, respectively. The column densities of the (CO)-C-13 and (CO)-O-18 emission lines are estimated to be 0.2 x 10(16) < N-13CO < 3.7 x 10(17) cm(-2) and 0.4 x 10(15) < N-C18O < 3.5 x 10(16) cm(-2), respectively. The abundance ratios between (CO)-C-13 and (CO)-O-18, X-13CO/X-C18O, are found to be 5.7-33.0. The mean value of X-13CO/X-C18O in the nearly edge-on photon-dominated regions is found to be 16.47 +/- 0.10, which is a third larger than that the solar system value of 5.5. The mean value of X-13CO/X-C18O in the other regions is found to be 12.29 +/- 0.02. The difference of the abundance ratio is most likely due to the selective FUV photodissociation of (CO)-O-18., EDP SCIENCES S A
Astronomy & Astrophysics, 2014年04月, ［査読有り］

High-Resolution Submillimeter and Near-Infrared Studies of the Transition Disk around Sz 91
Tsukagoshi; T.; Momose; M. (2nd author); & 58 authors, To reveal the structures of a transition disk around a young stellar object in Lupus, Sz 91, we have performed aperture synthesis 345 GHz continuum and CO(3-2) observations with the Submillimeter Array (similar to 1"-3" resolution) and high-resolution imaging of polarized intensity at the K-s-band using the HiCIAO instrument on the Subaru Telescope (0".25 resolution). Our observations successfully resolved the inner and outer radii of the dust disk to be 65 and 170 AU, respectively, which indicates that Sz 91 is a transition disk source with one of the largest known inner holes. The model fitting analysis of the spectral energy distribution reveals an H-2 mass of 2.4 Chi 10(-3) M-circle dot in the cold (T < 30 K) outer part at 65 AU < r < 170 AU by assuming a canonical gas-to-dust mass ratio of 100, although a small amount (> 3 Chi 10(-9)M(circle dot)) of hot (T similar to 180 K) dust possibly remains inside the inner hole of the disk. The structure of the hot component could be interpreted as either an unresolved self-luminous companion body (not directly detected in our observations) or a narrow ring inside the inner hole. Significant CO(3-2) emission with a velocity gradient along the major axis of the dust disk is concentrated on the Sz 91 position, suggesting a rotating gas disk with a radius of 420 AU. The Sz 91 disk is possibly a rare disk in an evolutionary stage immediately after the formation of protoplanets because of the large inner hole and the lower disk mass than other transition disks studied thus far., IOP PUBLISHING LTD
The Astrophysical Journal, 2014年03月, ［査読有り］

An Observational Study of the Temperature and Surface Density Structures of a Typical Full Disk around MWC 480
Akiyama; E.; Momose; M.; Kitamura; Y.; Tsukagoshi; T.; Shimada; S.; Koyamatsu; S.; & Hayashi; H., This paper presents observations of a protoplanetary disk around a Herbig Ae star, MWC480, in 12CO(J = 1-0), 12CO(J = 3-2), 13CO(J = 1-0), and C18O (J = 1-0) emission lines. Double-peaked emission profiles originating from the rotating circumstellar disk were detected in all of the lines. The vertical temperature and radial surface density structures of the outer region of the disk were derived by applying the similarity solution in the standard accretion disk model. Taking advantage of differences in the height of the photosphere among the CO lines, the temperature in the uppermost 12CO(J = 3-2) emitting layer was shown to be about 3-times higher than that of any other CO emitting region, suggesting that there are at least two distinct temperature regions. Our modeling succeeds in describing all of the observational results obtained in the four CO lines, particularly different emission extents at different frequencies, by a single set of the parameters for a disk model. Since the similarity solution model could be the most suitable for the radial surface density structure it is likely that the disk around MWC480 evolves by transferring angular momentum outward via viscous diffusion. Although further quantitative studies are required for identifying what disk model is the best for describing physical disk structures, our results suggest the potential advantage of the similarity solution model, indicating that disks around Herbig Ae/Be stars likely have diffused gas in the outer regions, and that the disk surface density exponentially decreases with increasing radial distance. © 2013. Astronomical Society of Japan.
Publications of the Astronomical Society of Japan, 2013年12月, ［査読有り］

Local Enhancement of the Surface Density in the Protoplanetary Ring Surrounding HD 142527
Fukagawa; M.; Tsukagoshi; T.; Momose; M. (3rd author); & 15 authors, We report on ALMA observations of the dust continuum, and 13COJ = 3-2 and C18O J = 3-2 line emission toward a gapped protoplanetary disk around HD 142527. The outer horseshoe-shaped disk shows a strong azimuthal asymmetry in the dust continuum with a ratio of ∼30 to 1 at 336 GHz between the northern peak and the southwestern minimum. In addition, the maximum brightness temperature of 24K at its northern area is exceptionally high at 160 au from a star. To evaluate the surface density in this region, the grain temperature needed constraining, and was estimated from the optically thick 13COJ = 3-2 emission. The lower limit of the peak surface density was then calculated to be 28 g cm-2 by assuming a canonical gas-to-dust mass ratio of 100. This finding implies that the region is locally too massive to withstand self-gravity, since Toomre's Q ≲ 1-2, and thus it may collapse into a gaseous protoplanet. Another possibility is that the gas mass is low enough to be gravitationally stable, and only dust grains are accumulated. In this case, a lower gas-to-dust ratio by at least 1 order of magnitude is required, implying the possible formation of a rocky planetary core. © 2013. Astronomical Society of Japan.
Publications of the Astronomical Society of Japan,, 2013年12月, ［査読有り］

A Large Millimeter and Submillimeter Telescope Project: ALMA-SPICA Synergy Telescope (``ASTE-II'')　　　　　　　　　　　　　　　
Kawabe, R.; Kohno, K.; Yamamoto, S.; Tamura, Y.; Totani, T.; Kitayama, T.; Komatsu, E.; Onishi, T.; Oshima, T.; Honma, M.; Matsuhara, H.; Nakanishi, H.; Iono, D.; Kuno, N.; Momose, M.; New Telescope Working Group, Here we report on the new medium-scale plan in Japan to construct a 30 - 50 m class millimeter (mm) and sub-mm single dish telescope. The main observing frequency of the telescope is 70 to 420 GHz, which just covers main atmospheric windows at mm and sub-mm wavelengths in good observing sites such as the ALMA site. We are also aiming at observations at higher frequency up to 1 THz with the limited use of the antenna surface, e.g., under-illumination of the telescope. One of important science goals in this new telescope project is unveiling the large scale structure (LSS) of the high-z universe and cosmic star formation history by spectroscopic surveys of high-z galaxies in CO and [CII] lines. With exploiting synergy with ALMA and possibly SPICA, this telescope can contribute to the breadth of astronomy and astrophysics, e.g., astrochemistry, star formation in the Galaxy and galaxies, cosmology, and sub-mm VLBI.

...
New Trends in Radio Astronomy in the ALMA Era: The 30th Anniversary of Nobeyama Radio Observatory, 2013年10月, ［査読有り］

Extensive [CI] Mapping toward the Orion-A Giant Molecular Cloud
Shimajiri; Y.; Sakai; T.; Tsukagoshi; T.; Kitamura; Y.; Momose; M.; Saito; M.; Oshima; T.; Kohno; K. & Kawabe; R., We have carried out wide-field (0.17 deg2) and high-angular resolution (21.″3 ∼ 0.04 pc) observations in the [C I] line toward the Orion-A giant molecular cloud with the Atacama Submillimeter Telescope Experiment 10 m telescope in the On-The-Fly mode. The overall features of the [C I] emission are similar to those of the 12CO (J = 1-0) emission by Shimajiri et al. in 2011
the total intensity ratio of the [C I] to CO emission ranges from 0.05 to 0.2. The optical depth of the [C I] emission is found to be 0.1-0.75, suggesting optically thin emission. The column density of the [C I] emission is estimated to be (1.0-19) × 1017 cm-2. These results are consistent with the results of the previous [C I] observations with a low-angular resolution of 2.′2. In the nearly edge-on photon-dominated regions (PDRs) and their candidates of the Orion Bar, DLSF, M 43 Shell, and Region D, the distributions of the [C I] emission coincide with those of the 12CO emission, inconsistent with the prediction by the plane-parallel PDR model. In addition, the [C I] distribution in the Orion A cloud is found to be more similar to those of the 13CO (J = 1-0), C18O (J = 1-0), and H13CO+ (J = 1-0) lines than that of the 12CO (J = 1-0) line, suggesting that the [C I] emission is not limited to the cloud surface, but is tracing the dense, inner parts of the cloud. © 2013. The American Astronomical Society. All rights reserved.
The Astrophysical Journal, 2013年09月, ［査読有り］

High-contrast Near-infrared Imaging Polarimetry of the Protoplanetary Disk around RY TAU
Takami; M.; Momose; M. (14th author); & 51 authors, We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at the H band at a high resolution (similar to 0 ''.05) for the first time, using Subaru/HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk., IOP PUBLISHING LTD
The Astrophysical Journal, 2013年08月, ［査読有り］

Development of 32-m Radio Telescopes for Monitoring Observations of Methanol Masers, H2O Masers, and Radio Continuum
Y. Yonekura; Y. Saito; T. Saito; T. Mori; K. L. Soon; M. Momose; M. Yokosawa; H. Ogawa; K. Fujisawa; K. Sugiyama; K. Motogi; H. Takaba; K. Sorai; N. Nakai; S. Kameno; H. Kobayashi; N. Kawaguchi; K. Hachisuka, We report the renovation of two satellite-communication antennas, named Takahagi and Hitachi 32-m antennas, into cm-wave radio telescopes. Both antennas have been successfully renovated into radio telescopes until 2012. VLBI observations at 6.7, 8, and 22 GHz have been successful since 2010. We have started single-dish observations of methanol masers at 6.7 GHz and H2O masers at 22 GHz from 2013., ASTRONOMICAL SOC PACIFIC
NEW TRENDS IN RADIO ASTRONOMY IN THE ALMA ERA: THE 30TH ANNIVERSARY OF NOBEYAMA RADIO OBSERVATORY, 2013年, ［査読有り］

Mapping Observation toward Protostellar Core L1527
Kiyokane, K; Saito, M; Saigo, K; Kurono, Y; Momose, M; Tsukagoshi, T; and NR; SF-Legacy Team
New Trends in Radio Astronomy in the ALMA Era: The 30th Anniversary of Nobeyama Radio Observatory, 2013年

Temperature and Surface Density Structures of a Typical Full Disk around MWC 480
Akiyama, E; Momose, M; Tsukagoshi, T; Kitamura, Y
New Trends in Radio Astronomy in the ALMA Era: The 30th Anniversary of Nobeyama Radio Observatory, 2013年

Submillimeter and Near Infrared Studies for the Evolved Transition Disk around Sz 91
Tsukagoshi, T; Momose, M; Hashimoto, J; Kudo, T; Andrews, S; Ohashi, N; Kitamura, Y; Saito, M; Wilner, D; Tamura, M; Kawabe, R
New Trends in Radio Astronomy in the ALMA Era: The 30th Anniversary of Nobeyama Radio Observatory, 2013年

Spectral-Line Survey at Millimeter and Submillimeter Wavelengths toward an Outflow-Shocked Region, OMC2-FIR 4
Yoshito Shimajiri; T. Sakai; Y. Kitamura; T. Tsukagoshi; M. Saito; F. Nakamura; M. Momose; R. Kawabe, We performed a spectral-line survey toward the three positions, an outflow shocked region, OMC2-FIR 4, in addition to the driving source of the molecular outflow, FIR 3, and the northern outflow lobe, FIR 3N, with the Nobeyama 45 m and ASTE telescopes. We detected more than 100 molecular lines. We found that the line profiles can be classified into the following two types: a single Gaussian component with a narrow (< 3 km s(-1)) velocity width and two Gaussian components with narrow and wide (> 3 km s(-1)) velocity widths. The wide components of CO, CS, HCO+, and HCN are also detected at three positions including FIR 3N, suggesting that these trace the molecular outflow. On the other hand, the wide components of SiO, SO, (CS)-S-34, CH3OH, (HCN)-C-13, and (HCN)-C-15 isotopes are detected only at the outflow shocked region, FIR 4, suggesting that these trace the outflow-shocked gas. In addition, the rotation diagram analysis revealed that the narrow components in both the two profile types correspond to the gas with a low temperature of 20-30 K, while the wide components trace a high temperature of 50-150 K. These results support our interpretation that the wide velocity components trace the molecular outflow and/or outflow-shocked gas., ASTRONOMICAL SOC PACIFIC
NEW TRENDS IN RADIO ASTRONOMY IN THE ALMA ERA: THE 30TH ANNIVERSARY OF NOBEYAMA RADIO OBSERVATORY, 2013年, ［査読有り］

Subaru Imaging of Asymmetric Features in a Transitional Disk in Upper Scorpius
Mayama; S.; Momose; M. (12nd author); & 53 authors, We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around the star 2MASS J16042165-2130284 obtained with HiCIAO mounted on the Subaru 8.2 m telescope. We present our H-band data, which clearly exhibit a resolved, face-on disk with a large inner hole for the first time at infrared wavelengths. We detect the centrosymmetric polarization pattern in the circumstellar material as has been observed in other disks. Elliptical fitting gives the semimajor axis, semiminor axis, and position angle (P.A.) of the disk as 63 AU, 62 AU, and -14 degrees, respectively. The disk is asymmetric, with one dip located at P.A.s of similar to 85 degrees. Our observed disk size agrees well with a previous study of dust and CO emission at submillimeter wavelength with Submillimeter Array. Hence, the near-infrared light is interpreted as scattered light reflected from the inner edge of the disk. Our observations also detect an elongated arc (50 AU) extending over the disk inner hole. It emanates at the inner edge of the western side of the disk, extending inward first, then curving to the northeast. We discuss the possibility that the inner hole, the dip, and the arc that we have observed may be related to the existence of unseen bodies within the disk., IOP PUBLISHING LTD
The Astrophysical Journal, 2012年12月, ［査読有り］

High-Resolution Near-Infrared Polarimetry of a Circumstellar Disk around UX Tau A
Tanii; R.; Momose; M. (22nd author); & 66 authors, We present H-band polarimetric imagery of UX Tau A taken with HiCIAO/AO188 on the Subaru Telescope. UX Tau A has been classified as a pre-transitional disk object, with a gap structure separating its inner and outer disks. Our imagery taken with the 0 ''.15 (21 AU) radius coronagraphic mask has revealed a strongly polarized circumstellar disk surrounding UX Tau A, which extends to 120 AU, at a spatial resolution of 0 ''.1 (14 AU). It is inclined by 46 degrees +/- 2 degrees, since the west side is nearest. Although SED modeling and sub-millimeter imagery have suggested the presence of a gap in the disk, with the inner edge of the outer disk estimated to be located at 25-30 AU, we detect no evidence of a gap at the limit of our inner working angle (23 AU) at the near-infrared wavelength. We attribute the observed strong polarization (up to 66%) to light scattering by dust grains in the disk. However, neither polarization models of the circumstellar disk based on Rayleigh-scattering nor Mie-scattering approximations were consistent with the observed azimuthal profile of the polarization degrees of the disk. Instead, a geometric optics model of the disk with nonspherical grains with radii of 30 mu m is consistent with the observed profile. We suggest that the dust grains have experienced frequent collisional coagulations, and have grown in the circumstellar disk of UX Tau A., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2012年12月, ［査読有り］

DISCOVERY OF SMALL-SCALE SPIRAL STRUCTURES IN THE DISK OF SAO 206462 (HD 135344B): IMPLICATIONS FOR THE PHYSICAL STATE OF THE DISK FROM SPIRAL DENSITY WAVE THEORY
T. Muto; C. A. Grady; J. Hashimoto; M. Fukagawa; J. B. Hornbeck; M. Sitko; R. Russell; C. Werren; M. Cure; T. Currie; N. Ohashi; Y. Okamoto; M. Momose; M. Honda; S. Inutsuka; T. Takeuchi; R. Dong; L. Abe; W. Brandner; T. Brandt; J. Carson; S. Egner; M. Feldt; T. Fukue; M. Goto; O. Guyon; Y. Hayano; M. Hayashi; S. Hayashi; T. Henning; K. W. Hodapp; M. Ishii; M. Iye; M. Janson; R. Kandori; G. R. Knapp; T. Kudo; N. Kusakabe; M. Kuzuhara; T. Matsuo; S. Mayama; M. W. McElwain; S. Miyama; J- Morino; A. Moro-Martin; T. Nishimura; T-S Pyo; E. Serabyn; H. Suto; R. Suzuki; M. Takami; N. Takato; H. Terada; C. Thalmann; D. Tomono; E. L. Turner; M. Watanabe; J. P. Wisniewski; T. Yamada; H. Takami; T. Usuda; M. Tamura, We present high-resolution, H-band imaging observations, collected with Subaru/HiCIAO, of the scattered light from the transitional disk around SAO 206462 (HD 135344B). Although previous sub-mm imagery suggested the existence of a dust-depleted cavity at r <= 46 AU, our observations reveal the presence of scattered light components as close as 0 ''.2 (similar to 28 AU) from the star. Moreover, we have discovered two small-scale spiral structures lying within 0.'' 5 (similar to 70 AU). We present models for the spiral structures using the spiral density wave theory, and derive a disk aspect ratio of h similar to 0.1, which is consistent with previous sub-mm observations. This model can potentially give estimates of the temperature and rotation profiles of the disk based on dynamical processes, independently from sub-mm observations. It also predicts the evolution of the spiral structures, which can be observable on timescales of 10-20 years, providing conclusive tests of the model. While we cannot uniquely identify the origin of these spirals, planets embedded in the disk may be capable of exciting the observed morphology. Assuming that this is the case, we can make predictions on the locations and, possibly, the masses of the unseen planets. Such planets may be detected by future multi-wavelength observations., IOP PUBLISHING LTD
ASTROPHYSICAL JOURNAL LETTERS, 2012年04月, ［査読有り］

EVIDENCE FOR CLOUD-CLOUD COLLISION AND PARSEC-SCALE STELLAR FEEDBACK WITHIN THE L1641-N REGION
Fumitaka Nakamura; Tomoya Miura; Yoshimi Kitamura; Yoshito Shimajiri; Ryohei Kawabe; Toshiya Akashi; Norio Ikeda; Takashi Tsukagoshi; Munetake Momose; Ryoichi Nishi; Zhi-Yun Li, We present high spatial resolution (CO)-C-12 (J = 1-0) images taken by the Nobeyama 45 m telescope toward a 48' x 48' area, including the L1641-N cluster. The effective spatial resolution of the maps is 21 '', corresponding to 0.04 pc at a distance of 400 pc. A recent 1.1 mm dust continuum map reveals that the dense gas is concentrated in several thin filaments. We find that a few dust filaments are located at the parts where (CO)-C-12 (J = 1-0) emission drops sharply. Furthermore, the filaments have two components with different velocities. The velocity difference between the two components is about 3 km s(-1), corresponding to a Mach number of 10, significantly larger than the local turbulent velocity in the cloud. These facts imply that the collision of the two components (hereafter, the cloud-cloud collision) possibly contributed to the formation of these filaments. Since the two components appear to overlap toward the filaments on the plane of the sky, the collision may have occurred almost along the line of sight. Star formation in the L1641-N cluster was probably triggered by such a collision. We also find several parsec-scale CO shells whose centers are close to either the L1641-N cluster or the V 380 Ori cluster. We propose that these shells were created by multiple winds and/or outflows from cluster young stellar objects, i.e., "protocluster winds." One exceptional dust filament located at the western cloud edge lies along a shell; it is presumably part of the expanding shell. Both the cloud-cloud collision and protocluster winds are likely to influence the cloud structure and kinematics in this region., IOP PUBLISHING LTD
ASTROPHYSICAL JOURNAL, 2012年02月, ［査読有り］

Aperture Synthesis Observations Toward The Protostellar Systems L1551 Irs 5 And Hl Tau: Rotation In The Infalling Envelope
Saito, M; Kitamura, Y; Momose, M; Tsukagoshi, T; Kawabe, R
American Astronomical Society Meeting Abstracts #219, 2012年

Thermal Structure of a Protoplanetary Disk around HD 163296: A Study of Vertical Temperature Distribution by CO Emission Lines
Akiyama; E.; Momose; M.; Hayashi; H.; Kitamura; Y., This paper presents observations of a protoplanetary disk around the Herbig Ae star HD 163296 in (CO)-C-12 (J = 1-0), (CO)-C-12 (J = 3-2), (CO)-C-13 (J = 1-0), and (CO)-C-13 (J = 3-2) emission lines. Double-peaked emission profiles originating from the rotating circumstellar disk were detected in all of the lines. The disk parameters were estimated from model calculations in which the radial distribution of the temperature or surface density inside the disk had a power-law form. The surface density should be sufficiently high so that the disk is optically thick for all of the CO lines, as discussed in previous studies based on interferometric observations. The temperature and outer radius of the disk were also confirmed to be consistent with the previous results. Taking advantage of the difference in the position of the photosphere among the CO lines, we revealed the temperature distribution in the vertical direction. The temperature of the (CO)-C-12 (J = 3-2) emitting region is about twice higher than that of any other CO emitting region; the former is 58.5 +/- 9.5 K, while the latter is 31 +/- 15K at 100 AU from the central star, suggesting that there are at least two distinct temperature regions. The best-fit temperature for (CO)-C-13 (J = 1-0) that should trace the deepest region of the disk is even lower, implying that there is also a different temperature region deep inside of the disk. Such a vertical temperature distribution in a disk was identified both in T Tauri and Herbig Ae stars (e.g., DM Tau, AB Aur, and HD 31648), and this should be a common feature in protoplanetary disks., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2011年10月01日, ［査読有り］

The Millimeter Sky Transparency Imager (MiSTI)
Tamura Yoichi; Kawabe Ryohei; Kohno Kotaro; FUKUHARA Masayuki; MOMOSE Munetake; EZAWA Hajime; KUBOI Akihito; SEKIGUCHI Tomohiko; KAMAZAKI Takeshi; VILA-VILARO Baltasar; NAKAGAWA Yuki; OKADA Norio, Astronomical Society of Japan
PASJ : publications of the Astronomical Society of Japan, 2011年04月, ［査読有り］

Direct Imaging of Fine Structures in Giant Planet-forming Regions of the Protoplanetary Disk Around AB Aurigae
Hashimoto; J.; Momose; M. (第16著者,他50名), We report high-resolution 1.6 mu m polarized intensity (PI) images of the circumstellar disk around the Herbig Ae star AB Aur at a radial distance of 22 AU (0 ''.15) up to 554 AU (3 ''.85), which have been obtained by the high-contrast instrument HiCIAO with the dual-beam polarimetry. We revealed complicated and asymmetrical structures in the inner part (less than or similar to 140 AU) of the disk while confirming the previously reported outer (r greater than or similar to 200 AU) spiral structure. We have imaged a double ring structure at similar to 40 and similar to 100 AU and a ring-like gap between the two. We found a significant discrepancy of inclination angles between two rings, which may indicate that the disk of AB Aur is warped. Furthermore, we found seven dips (the typical size is similar to 45 AU or less) within two rings, as well as three prominent PI peaks at similar to 40 AU. The observed structures, including a bumpy double ring, a ring-like gap, and a warped disk in the innermost regions, provide essential information for understanding the formation mechanism of recently detected wide-orbit (r > 20 AU) planets., IOP PUBLISHING LTD
The Astrophysical Journal, 2011年03月, ［査読有り］

New Panoramic View of 12CO and 1.1 mm Continuum Emission in the Orion A Molecular Cloud. I. Survey Overview and Possible External Triggers of Star Formation
Shimajiri; Y.; Momose; M. (第6著者,他18名), We present new, wide, and deep images in the 1.1 mm continuum and the (CO)-C-12 (J = 1-0) emission toward the northern part of the Orion A Giant Molecular Cloud (Orion-A GMC). The 1.1 mm data were taken with the AzTEC camera mounted on the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope in Chile, and the (CO)-C-12 (J = 1-0) data were with the 25 beam receiver (BEARS) on the Nobeyama Radio Observatory (NRO) 45 m telescope in the On-The-Fly (OTF) mode. The present AzTEC observations are the widest (1 degrees.7 x 2 degrees.3, corresponding to 12 pc x 17 pc) and the highest-sensitivity (similar to 9 mJy beam(-1)) 1.1 mm dust-continuum imaging of the Orion-A GMC with an effective spatial resolution of similar to 40 ''. The (CO)-C-12 (J = 1-0) image was taken over the northern 1 degrees.2 x 1 degrees.2 (corresponding 9 pc x 9 pc) area with a sensitivity of 0.93 K in T-MB, a velocity resolution of 1.0 km s(-1), and an effective spatial resolution of 21 ''. With these data, together with the MSX 8 mu m, Spitzer 24 mu m, and the 2MASS data, we have investigated the detailed structure and kinematics of molecular gas associated with the Orion-A GMC, and have found evidence for interactions between molecular clouds and the external forces that may trigger star formation. Two types of possible triggers were revealed: (1) Collisions of the diffuse gas on the cloud surface, particularly at the eastern side of the OMC-2/3 region, and (2) Irradiation of UV on the pre-existing filaments and dense molecular cloud cores. Our wide-field and high-sensitivity imaging has provided the first comprehensive view of the potential sites of triggered star formation in the Orion-A GMC., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2011年02月, ［査読有り］

Star Formation in the Orion A Molecular Cloud
Shimajiri, Y; Kawabe, R; Takakuwa, S; Saito, M; Tsukagoshi, T; Momose, M; Ikeda, N; Akiyama, E; Austermann, J. E; Ezawa, H; Fukue, K; Hiramatsu, M; Hughes, D; Kitamura, Y; Kohno, K; Kurono, Y; Scott, K. S; Wilson, G; Yoshida, A; Yun, M. S
EAS Publications Series, 2011年

Detection of Strong Millimeter Emission from the Circumstellar Dust Disk Around V1094 Sco: Cold and Massive Disk around a T Tauri Star in a Quiescent Accretion Phase?
Tsukagoshi; T.; Momose; M.(第4著者,他17名), We present the discovery of a cold massive dust disk around the T Tauri star V1094 Sco in the Lupus molecular cloud from the 1.1 mm continuum observations with AzTEC on ASTE. A compact (r less than or similar to 320 AU) continuum emission coincides with the stellar position having a flux density of 272 mJy, which is the largest among T Tauri stars in Lupus. We also present the detection of molecular gas associated with the star in the five-point observations in (CO)-C-12 J = 3-2 and (CO)-C-13 J = 3-2. Since our (CO)-C-12 and (CO)-C-13 observations did not show any signature of a large-scale outflow or a massive envelope, the compact dust emission is likely to come from a disk around the star. The observed spectral energy distribution (SED) of V1094 Sco shows no distinct turnover from near-infrared to millimeter wavelengths, can be well described by a flattened disk for the dust component, and no clear dip feature around 10 mu m suggestive of the absence of an inner hole in the disk. We fit a simple power-law disk model to the observed SED. The estimated disk mass ranges from 0.03 M-circle dot to greater than or similar to 0.12 M-circle dot, which is one or two orders of magnitude larger than the median disk mass of T Tauri stars in Taurus. The resultant temperature is lower than that of a flared disk with well-mixed dust in hydrostatic equilibrium and is probably attributed to the flattened disk geometry for the dust which the central star cannot illuminate efficiently. From these results, together with the fact that there is no signature of an inner hole in the SED, we suggest that the dust grains in the disk around V1094 Sco sank into the midplane with grain growth by coalescence and are in the evolutional stage just prior to or at the formation of planetesimals., IOP PUBLISHING LTD
The Astrophysical Journal, 2011年01月

系外惑星研究 —その起源と性質の理解に向けて—
百瀬宗武, 日本赤外線学会
日本赤外線学会誌, 2010年05月, ［査読有り］

High-resolution Observations of Dust Continuum Emission at 340 GHz from the Low-Mass T Tauri Star FN Tauri
Momose; M.; Ohashi; N.; Kudo; T.; Tamura; M.; & Kitamura; Y., 筆頭著者, FN Tau is a rare example of a very low-mass T Tauri star that exhibits a spatially resolved nebulosity in near-infrared scattering light. To directly derive the parameters of a circumstellar disk around FN Tau, observations of dust continuum emission at 340 GHz are carried out with the Submillimeter Array (SMA). A point-like dust continuum emission was detected with a synthesized beam of similar to 0 ''.7 in FWHM. From the analysis of the visibility plot, the radius of the emission is estimated to be <= 0 ''.29, corresponding to 41 AU. This is much smaller than the radius of the nebulosity, 1 ''.85 for its brighter part at 1.6 mu m. The 340 GHz continuum emission observed with the SMA and the photometric data at lambda <= 70 mu m are explained by a power-law disk model whose outer radius and mass are 41 AU and (0.24-5.9) x 10(-3) M-circle dot, respectively, if the exponent of dust mass opacity (beta) is assumed to be 0-2. The disk model cannot fully reproduce the flux density at 230 GHz obtained with the IRAM 30 m telescope, suggesting that there is another extended "halo" component that is missed in the SMA observations. By requiring the halo not to be detected with the SMA, the lower limit to the size of the halo is evaluated to be between 174 AU and 574 AU, depending on the assumed beta value. This size is comparable to the near-infrared nebulosity, implying that the halo unseen with the SMA corresponds to the origin of the near-infrared nebulosity. The halo can contain mass comparable to or at most 8 times greater than that of the inner power-law disk, but its surface density should be lower than that at the outer edge of the power-law disk by more than 1 order of magnitude. The physical nature of the halo is unclear, but it may be the periphery of a flared circumstellar disk that is not described well in terms of a power-law disk model, or a remnant of a protostellar envelope having flattened structure., IOP PUBLISHING LTD
The Astrophysical Journal, 2010年03月, ［査読有り］

Search of SO_2 in the Martian atmosphere by ground-based ,submillimeter observation
Nakagawa; H.; Momose; M. (第11著者); 他12名, We searched sulfur oxide (SO2 and SO) in the Martian atmosphere by the Atacama Submillimeter Telescope Experiment (ASTE). Sulfur oxide is one of the most evident species in terrestrial volcanic gases. Although it has not yet been detected at Mars, this detection can constraint the Martian crustal and volcanic activities. We observed northern winter of Mars on 26 December 2007 (L-s=8.1 degrees) in 346 GHz range with similar to 1 h integration. We get the upper limit of the SO2 mixing ratio, 2 ppb. This is mostly equivalent to the value observed in northern summer (L-s=205 degrees) (Krasnopolsky, 2005). We concluded that the crustal or volcanic gas produced into the atmosphere is tenuous in northern winter. Even at Mars, it can be expected that the crustal or volcanic gas includes non-negligible amount of SO2 produced as degasification from the magma. Our result and recent detections of CH4 suggest a possibility of some kind of carbon hydride sources under the ground reservoir, independent of usual crustal and volcanic activities. (C) 2009 Elsevier Ltd. All rights reserved, PERGAMON-ELSEVIER SCIENCE LTD
Planetary and Space Science, 2009年12月, ［査読有り］

Direct detection of a flared disk around a young massive star HD200775 and its 10 to 1000AU scale properties
Okamoto; K. Y.; Kataza; H.; Momose; M. (第5著者) 他9名, We made mid-infrared (MIR) observations of the 10M(circle dot) Herbig Be star HD200775 with the Cooled Mid-Infrared Camera and Spectrometer on the 8.2 m Subaru Telescope. We discovered diffuse emission of an elliptical shape extended in the north-south direction in an similar to 1000 AU radius around unresolved excess emission. The diffuse emission is perpendicular to the cavity wall formed by the past outflow activity and is parallel to the projected major axis of the central close binary orbit. The centers of the ellipse contours of the diffuse emission are shifted from the stellar position, and the amount of the shift increases as the contour brightness level decreases. The diffuse emission is well explained in all of geometry (the shape and the shift), size, and configuration by an inclined flared disk where only its surface emits the MIR photons. Our results give the first well-resolved infrared disk images around a massive star and strongly support that HD200775 is formed through the disk accretion. The disk survives the main accretion phase and shows a structure similar to that around lower mass stars with "disk atmosphere." At the same time, the disk also shows properties characteristic of massive stars such as photoevaporation traced by the 3.4 mm free-free emission and unusual silicate emission with a peak at 9.2 mu m, which is shorter than that of many astronomical objects. It provides a good place to compare the disk properties between massive and lower mass stars., IOP PUBLISHING LTD
The Astrophysical Journal, 2009年11月, ［査読有り］

Candidate Rotating Toroids around High-Mass (Proto)Stars
Furuya; R. S.; Cesaroni; R.; Takahashi; S.; Codella; C.; Momose; M.; & Beltran; M.T., Using the OVRO, Nobeyama, and IRAM millimeter arrays, we searched for "disk''-outflow systems in three high-mass (proto) star-forming regions: G16.59-0.05, G23.01-0.41, and G28.87+0.07. These were selected from a sample of NH3 cores (Codella, Testi, & Cesaroni) associated with OH and H2O maser emission (Foster & Caswell) and with no or very faint continuum emission. Our imaging of molecular line (including rotational transitions of CH3CN) and 3 mm dust continuum emission revealed that these are compact (less than or similar to 0.06Y0.13 pc), massive (similar to 100Y400M (circle dot)), and hot (similar to 100 K) molecular cores ( HMCs) that are likely sites of high-mass star formation prior to the appearance of ultracompact H II regions. All three sources turn out to be associated with molecular outflows from (CO)-C-12 and/or HCO+ J = 1-0 line imaging. In addition, velocity gradients of 10-100 km s(-1) pc(-1) in the innermost, densest regions of the G23.01-0.41 and G28.87+0.07 HMCs are identified along directions roughly perpendicular to the axes of the corresponding outflows. All the results suggest that these cores might be rotating about the outflow axis, although the contribution of rotation to gravitational equilibrium of the HMCs appears to be negligible. Our analysis indicates that the three HMCs are close to virial equilibrium due to turbulent pressure support. Comparison with other similar objects where rotating toroids have been identified so far shows that in our case rotation appears to be much less prominent; this can be explained by the combined effect of unfavorable projection, large distance, and limited angular resolution with the current interferometers., UNIV CHICAGO PRESS
The Astrophysical Journal, 2008年01月, ［査読有り］

Discovery of a Scattering Disk around the Low-Mass T Tauri Star FN Tauri
Kudo; T.; Momose; M.(第11著者) 他13名, We have discovered an optically thick, nearly face-on circumstellar disk around a single M5 classical T Tauri star, FN Tau, using the coronagraphic imager CIAO on the Subaru telescope. This is the least massive T Tauri star whose circumstellar structure has been directly imaged as a scattering disk. The surface brightness in the H band declines as a power law of r(-2.5 +/- 0.1) (110 AU <= r <= 260 AU), suggesting that the disk is flared. The disk morphology appears to be relatively featureless except for an azimuthal asymmetry in the surface brightness, indicating that the disk is not perfectly face-on but is slightly tilted. The disk mass, derived from a simple disk emission model with previous photometry at optical to millimeter wavelengths, is similar to 0.007 M-circle dot, 6% of the mass of the central star. The disk around FN Tau is one of the best targets for disk and planet formation studies around M stars., UNIV CHICAGO PRESS
The Astrophysical Journal, 2008年01月, ［査読有り］

Kinematics of SiO J = 8-7 Emission towards the HH 212 Jet
Takami M.; Takakuwa S.; Momose; M.; Hayashi M.; Davis C. J.; Pyo T-S; Nishikawa T.; Kohno; K., We present SiO J = 8-7 (347.3 GHz) observations towards HH 212 (Herbig-Haro object 212) using the ASTE (Atacama Submillimeter Telescope Experiment) telescope. Our observations with a 22"-diameter beam show that the SiO emission is highly concentrated within 1' of the driving source. We carefully compare the SiO observations with archival H-2 1-0 S(I) images and published H-2 echelle spectra. We find that, although the SiO velocities closely match the radial velocities seen in H2, the distributions of H2 and SiO emission differ markedly. We attribute the latter to the different excitation conditions required for H2 and SiO emission, particularly the higher critical density (n(H2) similar to 10(8) cm(-3)) of the SiO2 = 8-7 emission. The kinematic similarities imply that the H-2 and SiO are associated with the same internal working surfaces. We conclude that the SiO J = 8-7 emission has a potential for probing the jet/wind launching region through interferometric observations in the future, particularly for the youngest, most deeply embedded protostars where IR observations are not possible., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2006年06月, ［査読有り］

Relative Evolutionary Timescale of Hot Molecular Cores with Respect to Ultracompact H II Regions
Furuya R. S.; Cesaroni R.; Takahashi S.; Momose M.; Testi L.; Shinnaga H.; Codella C., Using the Owens Valley and Nobeyama Radio Observatory interferometers, we carried out an unbiased search for hot molecular cores and ultracompact (UC) H II regions toward the high-mass star-forming region G19.61-0.23. In addition, we performed 1.2 mm imaging with SIMBA and retrieved 3.5 and 2 cm images from the VLA archive database. The newly obtained 3 mm image brings information on a cluster of high-mass ( proto) stars located in the innermost and densest part of the parsec-scale clump detected in the 1.2 mm continuum. We identify a total of 10 high-mass young stellar objects: one hot core (HC) and nine UC H II regions, whose physical parameters are obtained from model fits to their continuum spectra. The ratio between the current and expected final radii of the UCH II regions ranges from 0.3 to 0.9, which leaves the possibility that all O-B stars formed simultaneously. Under the opposite assumption, namely, that star formation occurred randomly, we estimate that the HC lifetime is less than &SIM; 1/3 of that of UC H II regions on the basis of the source number ratio between them., UNIV CHICAGO PRESS
The Astrophysical Journal, 2005年05月, ［査読有り］

A Near-Infrared Study of the NGC 7538 Star-forming Region
Ojha, D. K; Momose, M
The Astrophysical Journal, 2004年02月, ［査読有り］

A Giant Flare on a T Tauri Star Observed at Millimeter Wavelengths
R. S. Furuya; H. Shinnaga; K. Nakanishi; M. Momose; M. Saito, We have conducted multi-epoch synthesis imaging of lambda = 2 and 3 millimeter (mm) continuum emission and near-infrared K-band (2.2 mum) imaging of a flare event in 2003 January that occurred on the young stellar object GMR-A, which is suggested to be a weak-line T Tauri star in the Orion cluster. Our turn data showed that the flare activity lasted for at least over 13 days, whereas the K-band magnitude did not change during this event. In addition, we have succeeded in detecting short time variations of flux on time scales of 15 minutes. The total energy of the flare is estimated to be similar to10(35-36)erg, which makes it one of the most energetic flares reported to date. Comparing the mm continuum luminosities with reported X-ray luminosities, we conclude that the mm flare was similar in nature to solar and other stellar flares. Our results will be a crucial step toward understanding magnetically induced stellar surface activities in T Tauri stars., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2003年12月, ［査読有り］

High Angular Resolution, Sensitive CS J = 2-1 and J = 3-2 Imaging of the Protostar L1551 NE: Evidence for Outflow-triggered Star Formation
S. Yokogawa; Y. Kitamura; M. Momose; R. Kawabe, High angular resolution and sensitive aperture synthesis observations of CS (J = 2-1) and CS (J = 3-2) emissions toward L1551 NE, the second brightest protostar in the Taurus molecular cloud, made with the Nobeyama Millimeter Array are presented. L1551 NE is categorized as a Class 0 object deeply embedded in the redshifted outflow lobe of L1551 IRS 5. Previous studies of the L1551 NE region in CS emission revealed the presence of shell-like components open toward L1551 IRS 5, which seem to trace low-velocity shocks in the swept-up shell driven by the outflow from L1551 IRS 5. In this study, significant CS emission around L1551 NE was detected at the eastern tip of the swept-up shell from V-lsr = 5.3 to 10.1 km s(-1), and the total mass of the dense gas is estimated to be 0.14 +/- 0.02 M-.. In addition, the following new structures were successfully revealed: a compact disklike component with a size of approximate to 1000 AU just at L1551 NE, an arc-shaped structure around L1551 NE, open toward L1551 NE, with a size of similar to 5000 AU, i. e., a bow shock, and a distinct velocity gradient of the dense gas, i. e., deceleration along the outflow axis of L1551 IRS 5. These features suggest that the CS emission traces the postshocked region where the dense gas associated with L1551 NE and the swept-up shell of the outflow from L1551 IRS 5 interact. Since the age of L1551 NE is comparable to the timescale of the interaction, it is plausible that the formation of L1551 NE was induced by the outflow impact. The compact structure of L1551 NE with a tiny envelope was also revealed, suggesting that the outer envelope of L1551 NE has been blown off by the outflow from L1551 IRS 5., UNIV CHICAGO PRESS
The Astrophysical Journal, 2003年09月, ［査読有り］

A submillimetre imaging polarimeter at the James Clerk Maxwell Telescope
J. S. Greaves; M. Momose (第9著者,他14名), A polarimeter has been built for use with the Submillimetre Common-User Bolometer Array (SCUBA), on the James Clerk Maxwell Telescope (JCMT) in Hawaii. SCUBA is the first of a new generation of highly sensitive submillimetre cameras, and the UK/Japan Polarimeter adds a polarimetric imaging/photometry capability in the wavelength range 350 to 2000 mum. Early science results range from measuring the synchrotron polarization of the black hole candidate Sgr A* to mapping magnetic fields inferred from polarized dust emission in Galactic star-forming clouds. We describe the instrument design, performance, observing techniques and data reduction processes, along with an assessment of the current and future scientific capability., OXFORD UNIV PRESS
Monthly Notice of the Royal Astronomical Society, 2003年04月, ［査読有り］

Interferometric Observations of Formaldehyde in the Protoplanetary Disk around LkCa 15
Y. Aikawa; M. Momose; W.F. Thi; G-J. van Zadelhoff; C. Qi; G.A. Blake; E.F. van Dishoeck, Emission from the 2(12)-1(11) line of H2CO has been detected and marginally resolved toward LkCa 15 by the Nobeyama Millimeter Array. The column density of H2CO is higher than that observed in DM Tau and than predicted by theoretical models of disk chemistry; also, the line-intensity profile is less centrally peaked than that for CO. A similar behavior is observed in other organic gaseous molecules in the LkCa 15 disk., OXFORD UNIV PRESS
Publications of the Astronomical Soceity of Japan, 2003年02月, ［査読有り］

Investigation of the Physical Properties of Protoplanetary Disks around T Tauri Stars by a 1 Arcsecond Imaging Survey: Evolution and Diversity of the Disks in Their Accretion Stage
Kitamura; Yoshimi; Momose; Munetake; Yokogawa; Sozo; Kawabe; Ryohei; Tamura; Motohide; Ida; Shigeru, We present the results of an imaging survey of protoplanetary disks around single T Tauri stars in Taurus. Thermal emission at 2 mm from dust in the disks has been imaged with a maximum spatial resolution of 1" by using the Nobeyama Millimeter Array. Disk images have been successfully obtained under almost uniform conditions for 13 T Tauri stars, two of which are thought to be embedded. We have derived the disk properties of outer radius, surface density distribution, mass, temperature distribution, and dust opacity coefficient, by analyzing both our images and the spectral energy distributions on the basis of two disk models: the usual power-law model and the standard model for viscous accretion disks. By examining correlations between the disk properties and disk clocks, we have found radial expansion of the disks with decreasing H line luminosity, a measure of disk evolution. This expansion can be interpreted as radial expansion of accretion disks due to outward transport of angular momentum with evolution. The increasing rate of the disk radius suggests that the viscosity has weak dependence on radius r and alphasimilar to0.01 for the alpha parameterization of the viscosity. The power-law index p of the surface density distribution [Sigma(r)=Sigma(0)(r/r(0))(-p)] is 0-1 in most cases, which is smaller than 1.5 adopted in the Hayashi model for the origin of our solar system, while the surface density at 100 AU is 0.1-10 g cm(-2), which is consistent with the extrapolated value in the Hayashi model. These facts may imply that in the disks of our sample it is very difficult to make planets like ours without redistribution of solids, if such low values for p hold even in the innermost regions., UNIV CHICAGO PRESS
The Astropysical Journal, 2002年12月, ［査読有り］

First Astronomical Fringe of A Test Correlator for the ALMA: Simultaneous achievement of Wideband and High Resolution
S.K. Okumuara; S. Iguchi; Y. Chikada; M. Momose; M. Okiura, The first astronomical fringe of a test correlator for the Atacama Large Millimeter/Submillimeter Array (ALMA) is obtained. The newly-developed test correlator system consists of two 4096-Msps Analog-to-Digital Converters (ADCs) and an FX-type correlator that can divide a 2-GHz correlation signal from one baseline into 131072 frequency channels. A fringe spectrum that contains 20 line features as well as continuum emission at similar to 86.2 GHz was obtained by an interferometric observation of the Orion-KL regions using this test system connected to the Nobeyama Millimeter Array (NMA), demonstrating that the realization of high frequency resolution over a wide bandwidth is technically feasible. The installation of such a correlator system in the ALMA will greatly enhance its capability of multi-line imaging., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2002年08月, ［査読有り］

Aperture synthesis observations of protoplanetary disks with the Nobeyama Millimeter Array
S Yokogawa; Y Kitamura; M Momose; R Kawabe, We have made aperture synthesis observations of 2 mm continuum emission from the dust particles around pre-main-sequence stars with the Nobeyama Millimeter Array (NMA). We observed HL Tau, DO Tau, and GM Aur in the Taurus-Auriga dark clouds. By using the sparsest configuration of the NMA, we achieved a 1" resolution which corresponds to 140 AU at the region. As a result, we have resolved disklike structures toward all the objects. The flux densities and beam deconvolved sizes of the disks are 150 mJy and 1.12" x 0.82" for HL Tau, 37 mJy and 0.79" x 0.38" for DO Tau, and 31 mJy and 1.39" x 0.76" for GM Aur. Using the disk sizes and the inclination angles which derived from our images and past studied SEDs, we determined the physical parameters of the disks., PERGAMON-ELSEVIER SCIENCE LTD
DUST IN THE SOLAR SYSTEM AND OTHER PLANETARY SYSTEMS, 2002年, ［査読有り］

Submillimeter Imaging Polarimetry of the NGC 7538 Region
M. Momose; M. Tamura; O. Kameya; J.S. Greaves; A. Chrysostomou; J. H. Hough; J. -I. Morino, 筆頭著者
The Astrophysical Journal, 2001年06月, ［査読有り］

Millimeter Continuum Image of the Circumstellar Disk around the Young Star Haro 6-5B
S. Yokogawa; Y. Kitamura; M. Momose; Y. Asaki; M. Tamura; S. Ida; R. Kawabe, Aperture synthesis observations of dust continuum emission at 2 mm from the class I object Hare 6-5B, made with the Nobeyama Millimeter Array, are presented. A disklike structure that coincides with the dark lane in the visible and near-infrared images is clearly resolved with a small synthesized beam of 1."33 x 1."21 with its position angle (P.A.) of 134 degrees, The beam-deconvolved size of the disk is 2."33 x 0."97 at P.A. = 138 degrees, and the total flux density is 36.7 +/- 2.6 mJy. The radius and inclination angle of the disk derived from the image are 309 +/- 18 AU and 67 degrees +/- 5 degrees, respectively. By model fitting of the spectral energy distribution of Haro 6-5B with these values, the power-law index of the dust opacity, beta, is derived to be 1.05 +/- 0.04 and the disk mass is calculated to be 0.021 +/- 0.002 M.. No extended emission with 1000 AU scale is detected, suggesting that the envelope around Hare 6-5B has been almost dissipated and that the object is a transient source from the protostar stage to the T Tauri stage., UNIV CHICAGO PRESS
The Astrophysical Journal, 2001年05月, ［査読有り］

The Most Luminous Protostars in Molecular Clouds: A Hint to Understand the Stellar Initial Mass Function
K. Dobashi; Y. Yonekura; T. Matsumoto; M. Momose; F. Sato; J.P. Bernard; H. Ogawa, The maximum luminosity of protostars forming in molecular clouds has been investigated as a function of the parent cloud mass on the basis of a rich cloud sample searched for in the literature. In total, we gathered 499 molecular clouds among the published data, out of which 243 clouds were found to be associated with protostellar candidates selected from the IRAS point-source catalog. A diagram of the maximum stellar luminosity in each cloud and the parent cloud mass shows that the protostars in the clouds associated with H II regions are apparently more luminous than those in clouds away from H II regions over the entire cloud mass range investigated (1 < M-CL/M-. < 10(6)). In addition, we found that there are well-defined upper and lower limits in the maximum stellar luminosity distribution with the lower limit having a steeper dependence on the cloud mass (L-MAX proportional to M-CL(1.5)) than the upper one (L-MAX proportional to M-CL(0.8)). All Of these features can be naturally accounted for if we assume that the luminosity function of protostars is controlled by the cloud mass and the external pressure imposed on the cloud surface. We introduce a simple model for the stellar luminosity function as a function of these quantities, which should be closely related to the stellar initial mass function., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2001年02月, ［査読有り］

1-GHz Bandwidth Digital Spectro-Correlator System for the Nobeyama Millimeter Array
S.K. Okumura; M. Momose (第2著者,他9名), We have developed 1-GHz bandwidth digital spectro-correlator system for the Nobeyama Millimeter Array (NMA). It consists of 2Gsample/sec.2bit analog-to-digital (A/D) converters and an ultra-wide band digital correlator. We developed two kinds of special-purpose LSI having functions of delay compensation and correlation, respectively. With these LSIs, the ultra-wide band digital correlator realizes 1024-MHz bandwidth spectroscopy with 128-channel resolution for 15-correlation data. This system allows us to observe radio continuum emission with about a two-times better signal-to-noise ratio than that of the previous correlator system. We started common-use observations with this new system from 1997 March; the system has been extended in order to obtain 21-correlation data for a 7-element "Rainbow" (NMA + 45-m telescope) interferometer system., OXFORD UNIV PRESS
Publications of the Astronomical Society of Japan, 2000年04月, ［査読有り］

アタカマ電波干渉計で探る惑星系円盤　　　　　　　　　　　　　　　
百瀬宗武
日本惑星科学会誌, 2000年01月, ［査読有り］

First Detection of Submillimeter Polarization from T Tauri Stars
M. Tamura; J. Hough; J.S. Greaves; J. -I. Morino; A. Chrysostomou; W. S. Holland; M. Momose, We report a first detection of polarization of the 850 mu m continuum emission from two T Tauri stars (TTSs), GM Aur and DG Tau. These are both single and classical TTSs. The emission mostly comes from the compact (r < 100 AU) accretion disks. The polarization (at similar to 3% level at 3 sigma) is interpreted in terms of thermal emission by magnetically aligned dust grains in the disk. Thus these submillimeter polarizations probe the magnetic field structure in the disk, while the previously reported millimeter/submillimeter polarizations of protostars and the transitional objects from the protostars to TTSs trace the magnetic fields in the larger envelope region. In both TTSs, the direction of the magnetic field inferred from our submillimeter polarizations is parallel to the plane of the compact dust disk measured by interferometric observations, suggesting the dominance of a toroidal magnetic field component in the disk. The magnetic evolution of the circumstellar environments is discussed, as well as the constraints on the MHD models of the jets and outflows from young stellar objects., IOP PUBLISHING LTD
The Astrophysical Journal, 1999年11月, ［査読有り］

Outflow and Disk around the Very Young Massive Star GH _2 O 092.67 + 03.07
J. P. Bernard; K. Dobashi; M. Momose, We present CS(J=2-1) interferometric observations obtained with the Nobeyama Millimeter Array (NMA) toward a protostar (GH2O 092.67 + 03.07) in the Cygnus OB7 giant molecular cloud (distance=800 pc). The data clearly indicate the presence of a compact (size similar or equal to 8 10(3) AU) and young outflow with dynamical time scale similar or equal to 3500 year. The outflow is surrounded by a massive gas condensation. The analysis of the gas dynamics shows the signature of an infalling and rotating disk, which could be the first clear detection of such motion around a young high mass star. Single dish data obtained with the Nobeyama 45m antenna in several molecular lines are used to derive the CS abundance and the optical depth of the CS(J=2-1) toward GH2O 092.67 + 03.07. We derive a total mass of similar or equal to 0.6 M-. and similar or equal to 12 M-. for the outflow and disk respectively. The comparison of the NMA data with a simple model of infalling disk indicates a mass of the central object in the range 4.0 < M* < 7.5 M-..
We propose that GH2O 092.67 + 03.07 is a dust condensation in the very early steps of forming a high mass star., EDP SCIENCES S A
Astronomy & Astrophysics, 1999年09月, ［査読有り］

Aperture Synthesis C ^{18} O( J=1-0 ) Observations of L1551 IRS 5: Detailed Structure of the Infalling Envelope
M. Momose; N. Ohashi; R. Kawabe; T. Nakano; M. Hayashi, 筆頭著者, We report aperture synthesis (CO)-O-18 J = 1-0 observations of L1551 IRS 5 with a spatial resolution of 2." 8 x 2." 5 using the Nobeyama Millimeter Array. We have detected an emission component centrally condensed around IRS 5, as well as a diffuse component extending in the north-south direction from the centrally condensed component. The centrally condensed component, 2380 x 1050 AU in size, is elongated in the direction perpendicular to the outflow axis, indicating the existence of a flattened circumstellar envelope around L1551 IRS 5. The mass of the centrally condensed component is estimated to be 0.062 M.. The position-velocity (P-V) diagrams reveal that the velocity held in the centrally condensed component is composed of infall and slight rotation. The infall velocity in the outer part is equal to the free-fall velocity around a central mass of similar to 0.1 M., e.g., 0.5 km s(-1) at r = 700 AU, whereas the rotation velocity, 0.24 km s(-1) at the same radius, gets prominent at inner radii with a radial dependence of r(-1). We make up P-V diagrams for the model envelopes with vertical structure, in which the matter falls under the gravity and eventually settles down in Keplerian rotation inside the centrifugal radius, and compare them with the observed P-V diagrams of the centrally condensed component. The main characteristics of the observed P-V diagrams are reproduced by either (1) an envelope with a moderately flattened density distribution, or (2) a spherical envelope with a bipolar cavity whose half-opening angle is about 50 degrees. Detailed comparison of the observed and model P-V diagrams suggests that the (CO)-O-18 J = 1-0 emission from the outer part of the centrally condensed component is well reproduced with the models with the central mass similar to 0.15 M. and the mass infall rate similar to 6 x 10(-6) M. yr(-1). However, the higher velocity features of the emission near the star cannot be reproduced unless the central mass is taken to be similar to 0.5 M.. These facts suggest either that the gas pressure and/or magnetic force dilute the effect of the gravity in the outer part of the envelope, or that the velocity structure inside the centrifugal radius deviates significantly from the Keplerian rotation., UNIV CHICAGO PRESS
The Astrophysical Journal, 1998年09月, ［査読有り］

電波天文で探る星・惑星系形成　　　　　　　　　　　　　　　
百瀬宗武
日本惑星科学会誌, 1998年09月, ［査読有り］

Rotation in the Protostellar Envelopes around IRAS 04169+2702 and IRAS 04365+2535: The Size Scale for Dynamical Collapse
N. Ohashi; M. Hayashi; P.T.P. Ho; M. Momose; M. Tamura; N. Hirano; A.I. Sargent, We report interferometric observations of two embedded protostar candidates, IRAS 04169 + 2702 and IRAS 04365+2535 (TMC-1A), in the Taurus molecular cloud. The (CO)-O-18 J = 1-0 emission from IRAS 04169 + 2702 reveals a flattened envelope 2200 AU x 1100 AU in size; there is a velocity gradient along the elongation axis, which in turn is perpendicular to the outflow direction. Since the rotational velocity corrected for inclination, 0.23 km s(-1) at 370 AU, gives an unacceptably small dynamical mass of 0.02 M. within that radius, we speculate that there is additional radial motion, possibly infall, in the flattened envelope. Around IRAS 04365+2535, a compact (CO)-C-13 J = 1-0 condensation similar to 1400 AU in size was detected. Again, the velocity gradient is perpendicular to the associated molecular outflow, but a rotation velocity of 0.87 km s(-1) at 580 AU radius is consistent with the condensation being a rotationally supported disk.
Combining our new data for the two sources with published observations of rotationally supported disks and infalling envelopes around five young stars associated with the Taurus molecular cloud enables us to compare local specific angular momenta of a significant sample of these sources on scales of 200-2000 AU with those of dense cores on 6000-80,000 AU (0.03-0.4 pc) scales. The specific angular momenta for infalling envelopes and rotationally supported disks are relatively constant, similar to 10(-3) km s(-1) pc, and are typically an order of magnitude smaller than those for dense cores. These results can be explained if the dynamical collapse of dense star-forming cores takes place inside radii of similar to 0.03 pc while the region outside this radius remains dynamically stable., UNIV CHICAGO PRESS
The Astrophysical Journal, 1997年10月, ［査読有り］

Interferometric Imaging of IRAS04368+2557 in the L1527 Molecular Cloud Core: A Dynamically Infalling Envelope with Rotation
N. Ohashi; M. Hayashi; P.T.P. Ho; M. Momose, We report new interferometric observations of IRAS 04368 + 2557 (L1527) in (CO)-C-13 (J = 1-0), (CO)-O-18 (J = 1-0), and 2.7 mm continuum emission using the Nobeyama Millimeter Array. The continuum map shows a well-defined emission peak with slightly extended features. The extended features are consistent with an 800 mu m continuum map. The (CO)-C-13 map shows blueshifted and redshifted outflowing shells characterized by a bipolar V-shape structure with a wide opening angle toward the east and west of the central source. Near the systemic velocity, a slightly blueshifted X-shaped condensation was detected in (CO)-C-13 with its peak coincident with the central source. The symmetrical distribution of the X-shaped condensation centered on the central source suggests that it is a circumstellar envelope surrounding the central source. The (CO)-O-18 map shows a flattened structure elongated in the north-south direction, perpendicular to the outflow axis, centered on the central source. This flattened structure correlates spatially with the (CO)-C-13 X-shaped condensation. Both eastern and western edges of the flattened structure are concave, as the (CO)-C-13 X-shaped condensation also shows, and they are spatially well anticorrelated with the distribution of the outflowing shells in both blueshifted and redshifted velocities. The flattened structure is hence naturally interpreted as a disklike flattened envelope with an almost edge-on configuration. Its radius and gas mass are estimated to be similar to 2000 AU and similar to 0.038 M., respectively.
The edge-on flattened envelope has both rotational and radial motions with the latter dominant. The large specific angular momentum carried by the envelope gas implies that the radial motion can be infall rather than outflow. The infall and rotation velocities are similar to 0.3 km s(-1) and similar to 0.05 km s(-1), respectively, at the envelope radius of 2000 AU. The flattened envelope is clearly not supported by rotation, but it is dynamically infalling. Its mass infall rate is similar to 1.1 x 10(-6) M. yr(-1) at 2000 AU in radius. This mass infall rate is consistent with that estimated from the bolometric luminosity of 1.4 L. and the mass of 0.1 M. of the central star. On the assumption that the mass infall rate is constant with time, the age of the central star is estimated to be similar to 10(5) yr, which is comparable to the typical age of protostars in Taurus, even though the central star in L1527 is identified as a very young class O source. The rotating motion of the flattened envelope is opposite to the large-scale rotation of the L1527 cloud, suggesting that the rotation of the flattened envelope did not originate from the large-scale rotation., UNIV CHICAGO PRESS
The Astrophysical Journal, 1997年01月, ［査読有り］

The Dispersing Cloud Core around T Tauri
M. Momose; N. Ohashi; R. Kawabe; M. Hayashi; & T. Nakano, 筆頭著者, We have made (CO)-C-13 (J = 1-0) observations of T Tauri with the Nobeyama Millimeter Array (NMA) and with the Nobeyama 45 m telescope. The (CO)-C-13 (J = 1-0) emission detected with the NMA shows three different features: (1) a pair of ringlike features surrounding T Tauri with a radius of 30 '' (corresponding to 4200 AU at the distance of 140 pc to T Tauri) at the velocities blueshifted and redshifted by less than 1 km s(-1) from the systemic velocity, (2) a blueshifted compact feature 3 '' east of T Tauri, and (3) another compact feature 7 '' southwest of T Tauri at velocities redshifted by more than 1 km s(-1). On the other hand, the (CO)-C-13 maps obtained with the 45 m telescope show a smoothly extended feature near the systemic velocity, which is missed in the NMA observations, as well as the above-mentioned three features. The total masses of gas detected with the NMA and the 45 m telescope are estimated to be (0.054-0.23) M(.) and (0.31-1.3) M(.), respectively. The difference in the estimated mass between the two observations is mainly due to resolving out of the smoothly extended feature in the NMA observations.
The (CO)-C-13 rings are interpreted as biconical outflowing shells in a nearly pole-on configuration. The high-velocity stellar wind ejected from T Tauri is estimated to be energetic enough to drive these outflowing shells. We have analyzed the three-dimensional structure of the shells by correcting for the projection effect on the plane of the sky, and we have found that the spatial extent of the shells is nearly equal to or slightly smaller than the typical size of the molecular cloud cores in the Taurus Molecular Cloud. This fact indicates that the outflowing shells are part of the parent cloud core that still remains around T Tauri, which is now dispersing under the influence of the stellar wind. Such an environment around T Tauri is quite different from those around typical T Tauri stars, which are associated only with compact gaseous components. These results suggest strongly that T Tauri is one of the objects in the transitional phase from the protostar stage, in which a central star is deeply embedded in an infalling envelope, to the T Tauri stage, in which a central star is surrounded by a compact circumstellar disk instead of a spatially extended envelope., IOP PUBLISHING LTD
The Astrophysical Journal, 1996年10月, ［査読有り］

Possible Infall in the Gas Disk around L1551-IRS 5
N. Ohashi; M. Hayashi; P.T.P. Ho; M. Momose; N. Hirano, We report observations of (CO)-C-13(J = 1-0) emission from L1551-IRS5 carried out with the Nobeyama Millimeter Array. We detected a strong and compact condensation associated with L1551-IRS5, and weaker extended components with ''U''-like features with a spatial resolution of 5.'' 1 x 3.'' 9 (P.A. = 159 degrees). The U-like features delineate the edges of the molecular outflow as well as the 2.2 mu infrared reflection nebula. This suggests that the extended component may be a dense shell swept up by the molecular outflow. The compact component was marginally resolved with the present angular resolution. The estimated deconvolved size is similar to 1200 x 670 AU with a position angle perpendicular to the optical jet. This elongated structure is very similar to the compact gaseous disk observed in (CO)-O-18 (J = 1-0). The (CO)-C-13 elongated structure may be more extended than the actually measured size, suggesting that the compact (CO)-C-13 gas is most probably the inner part of the gaseous disk around L1551-IRS5. The (CO)-C-13 disk has a velocity gradient along its minor axis, which can be explained in terms of infalling motion in the plane of the disk with a central mass of 0.5 M.. We estimate the mass accretion rate at 600 AU in radius to be 1.3-2.6 x 10(-5) M. yr(-1). The derived accretion rate might be larger than the accretion rate onto the star estimated from the bolometric luminosity of L1551-IRS5 on the assumption of steady accretion, which suggests that the accretion around L1551-IRS5 may also be nonsteady as was the case for HL Tau., UNIV CHICAGO PRESS
The Astrophysical Journal, 1996年08月, ［査読有り］

ALMAによる惑星形成研究のスタート
百瀬 宗武
遊・星・人 : 日本惑星科学会誌, 2014年03月25日

O5-07 HD142527に付随する非対称ギャップ円盤のALMA観測(口頭発表セッション5(円盤・物質),口頭発表)
百瀬 宗武; 深川 美里; 塚越 崇; 西合 一矢; 大橋 永芳; 北村 良実; 犬塚 修一郎; 武藤 恭之; 野村 英子; 竹内 拓; 小林 浩; 花輪 知幸; 秋山 永治; 本田 充彦; 藤原 英明; 片岡 章雅; 高橋 実道; 芝井 広
日本惑星科学会秋期講演会予稿集, 2013年11月20日

Near-Infrared Imaging Observations of Circumstellar Disk around HD 169142 with Subaru/HiCIAO
Momose; M.; Morita; A.; Okamoto; Y.; Fukagawa; M.; Honda; M.; Muto; T.; Takeuchi; T.; Hashimoto; J.; Tamura; M.; Seeds/Hiciao/Ao188 Teams
``New Trends in Radio Astronomy in the ALMA Era: The 30th Anniversary of Nobeyama Radio Observatory.'', Proceedings of a Symposium held in Hakone, Japan 3-8 December 2012 . (Astronomical Society of Pacific Conf. Series, San Francisco), 2013年10月
筆頭著者

Wide-field Imaging Survey of Dust Continuum Emissions at \lambda = 1.1 mm toward the Chamaeleon and Lupus Regions with AzTEC on ASTE %Research on exoplanets —Toward the understanding of their origin and nature—
Momose, M
Exoplanets and Disks: Their Formation and Diversity, Proceedinds of the International Conference, 2009年

ASTE Observations of Circumstellar Material around Nearby Pre-main Sequence Stars
Momose, M; Kitamura, Y; Sekiguchi, T; Kawabe, R; Saito, M; Sakamoto, S; Tsukagoshi, T
Proceedings of ``Science with the Atacama Large Millimeter Array'', (Springer) CD-ROM, 2008年
筆頭著者

Detailed CO Observations of the Protostellar Envelopes in the Taurus Molecular Cloud
Yokokawa, S; Kitamura, Y; Momose, M; Kawabe, R
Protostars and Planets V, Proceedings of the Conference held LPI Contribution No. 1286., 2005年

Investigation of the Physical Properties of Protoplanetary Disks around T Tauri Stars by a High-resolution Imaging Survey at \lambda = 2 mm
M. Momose; Y. Kitamura; S. Yokogawa; R. Kawabe; M. Tamura; S. Ida
``Proceedings of IAU 8th Asian Pacific Regional Meeting'', Volume 1, Edited by S. Ikeuchi, J. Hearnshaw & T. Hanawa (Astronomical Society of Pacific Conf. series 289, San Francisco), 2003年
筆頭著者

Recent Development of Digital Spectro-Correlators for Radio Interferometers - ALMA Second-Generation Correlator
Okumura; S. K.; Iguchi; S.; Chikada; Y.; Momose; M.
New technologies in VLBI, Proceedings of a symposium of the International VLBI Service for Geodesy (Astronomical Society of Pacific Conf. series 306, San Francisco), 2003年

The Most Luminous Protostars in Molecular Clouds: A Hint to Understand the Stellar Initial Mass Function
K. Dobashi; Y. Yonekura; T. Matsumoto; M. Momose; F. Sato; J.P. Bernard; H. Ogawa
``Proceedings of Infrared and Submillimeter Space Astronomy''(EAS Publications Series, Vol. 4), 2002年

Deep ^{13} CO( J=1-0 ) Imaging of the Protostar Haro 6-5B: Discovery of Rotational Motion in the Protostellar Disk
S. Yokogawa; Y. Kitamura; M. Momose; R. Kawabe
'Proceedings of IAU 8th Asian-Pacific Regional Meeting'', Volume II, Edited by S. Ikeuchi, J. Hearnshaw & T. Hanawa, (Astronomical Society of Japan), 2002年

HCO ^{+} (J = 1-0) Interferometry of the Shocked Outflow in the Orion-KL Region
T. Saito; M. Momose; Kawabe; R.; Sunada; K.; Sakamoto; S.; Kamazaki; T.; Hirano; N.
``Proceedings of the Conference on Chemistry as a Diagnostic of Star Formation'' (NRC Press, Ottawa), 2002年

Very large FX correlator system for enhanced ALMA
S.K. Okumura; Y. Chikada; M. Momose
Proc. SPIE, 2000年

RECENT DEVELOPEMENT AND SCIENTIFIC RESULTS WITH RAINBOW ARRAY
M. Momose
``Proceedings of the 4th East Asian Meeting on Astronomy'', ed. Chen,P.S. (Kunming: Yunnan Observatory, CAS),, 1999年

High Resolution Imaging of the Protostellar Envelope around L1551 IRS 5: Growth of the Circumstellar Disk
M. Momose
``Proceedings of the 4th East Asian Meeting on Astronomy'', ed. Chen,P.S. (Kunming: Yunnan Observatory, CAS),, 1999年

209 「レインボー干渉計」による原始星L1551 IRS5の原始惑星系円盤の高空間分解能観測(セッションV)
百瀬 宗武; 北村 良実; 川辺 良平
日本惑星科学会秋期講演会予稿集, 1998年10月13日

原始星エンベロープの構造と進化の観測的研究
百瀬宗武
天文月報, 1998年

Aperture Synthesis Observations of T Tauri in ^{13} CO (J=1-0)
M. Momose; N. Ohashi; R. Kawabe; M. Hayashi
`Disks and Outflows around Young Stars'', ed. S. Beckwith, A. Natta & J. Staude(Berlin: Springer), 1996年
筆頭著者

Aperture Synthesis Observations of T Tauri in ^{13} CO (J=1-0)
M. Momose; N. Ohashi; R. Kawabe; M. Hayashi
``Ground-Based Astronomy in Asia'', ed. N. Kaifu (Tokyo: NAOJ), 1996年
筆頭著者

現代の天文学 第9巻 太陽系と惑星（第二版）　　　　　　　　　　　　　　　
(編)井田茂,渡部潤一,佐々木晶, 分担執筆
日本評論社, 2021年08月25日
9784535607613

現代の天文学 第16巻 宇宙の観測(2) 電波天文学（第二版）　　　　　　　　　　　　　　　
(編)中井直正,福井康雄,坪井昌人, 分担執筆
日本評論社, 2020年07月15日
9784535607668

系外惑星の事典　　　　　　　　　　　　　　　
共著
朝倉書店, 2016年09月10日
9784254150216

現代の天文学 別巻 天文学事典　　　　　　　　　　　　　　　
共著
日本評論社, 2012年07月
9784535607385

現代の天文学 第16巻 宇宙の観測(2) 電波天文学　　　　　　　　　　　　　　　
共著
日本評論社, 2009年08月
9784535607361

現代の天文学 第6巻 星間物質と星形成　　　　　　　　　　　　　　　
(編)福井康雄・犬塚修一郎・大西利和・中井直正・舞原俊憲・水野亮, 分担執筆
日本評論社, 2008年09月
9784535607262

Astronomical Observations at Radio Wavelengths Exploring the Origin of Bio-related molecules　　　　　　　　　　　　　　　
Munetake MOMOSE
Japan Geoscience Union Meeting 2022, 2022年05月25日, Japan Geoscience Union, ［招待有り］
20220522, 20220603

ngVLAとGREX-PLUSの科学的シナジー　　　　　　　　　　　　　　　
百瀬宗武
GREX-PLUS サイエンス検討会, 2022年03月25日, GREX-PLUS サイエンス検討ワーキンググループ, ［招待有り］
20220324, 20220325

ngVLAとその日本参画に向けて　　　　　　　　　　　　　　　
百瀬宗武,ngVLA study group (NAOJ)
電波天文将来計画検討シンポジウム, 2022年03月08日, 宇宙電波懇談会, ［招待有り］
20220307, 20220308

銀河系外縁部分子雲のCMF探索とその意義　　　　　　　　　　　　　　　
百瀬宗武
低金属量環境下における星・惑星形成, 2021年12月09日, 泉奈都子, 下西隆, 徳田一起, 仲谷崚平, 福島肇, ,古家健次, 百瀬宗武, 安井千香子
20211208, 20211210

Structure of protoplanetary disks and magnetosphere of exoplanets explored by continuum emission at radio wavelengths
百瀬宗武
Linking the science of large interferometers in the 2030s, 2021年12月01日, ［招待有り］
20211130, 20211201

電波天文学の基礎
百瀬宗武
電波・干渉計サマースクール, 2021年09月16日, 国立天文台、総合研究大学院大学（物理科学研究科天文科学専攻）、アルマ科学諮問委員会、VLBI科学諮問委員会, ［招待有り］
20210916, 20210924

次世代大型電波干渉計 ngVLA　　　　　　　　　　　　　　　
百瀬宗武,ngVLA study group (NAOJ)
日本学術会議シンポジウム, 2021年08月10日, 日本学術会議 天文学・宇宙物理学分科会, ［招待有り］
20210809, 20210814

次世代大型電波干渉計 ngVLA　　　　　　　　　　　　　　　
百瀬宗武,ngVLA study group (NAOJ)
電波天文将来計画検討シンポジウム, 2021年07月31日, 宇宙電波懇談会, ［招待有り］
20210731, 20210731

2020年07月, 日本物理学会

1994年, 日本惑星科学会

1994年, 日本天文学会

国際電波科学連合

国際天文学連合

日本地球惑星科学連合

原始惑星系円盤の力学的詳細構造から理解する惑星系形成
基盤研究(B)
国立天文台
2022年04月 - 2025年03月

多様な星形成環境下における原始惑星系円盤の観測　　　　　　　　　　　　　　　
その他
2018年06月 - 2023年03月

多波長高解像度観測による原始惑星系円盤の解剖と惑星系形成過程の解明
天文学
茨城大学
2017年04月 - 2022年03月

太陽系外惑星の新機軸：地球型惑星へ
新学術領域研究(研究領域提案型)
国立天文台
2016年04月 - 2017年03月

円盤から惑星へ　　　　　　　　　　　　　　　
その他
2011年08月 - 2016年03月

太陽系外惑星の新機軸：地球型惑星へ
新学術領域研究(研究領域提案型)
2011年04月 - 2016年03月

メタノールメーザー源の大規模モニタリングサーベイによる大質量星形成機構の解明
基盤研究(B)
茨城大学
2012年04月 - 2015年03月

南天サブミリ波観測による原始惑星系円盤の物理・化学構造の解明
特定領域研究
茨城大学
2007年 - 2008年

高精度サブミリ波観測による星・惑星系形成の研究
基盤研究(A)
国立天文台
2006年 - 2008年

ミリ波・サブミリ波高感度・高解像度観測による原始星円盤の物理構造の解明
基盤研究(C)
茨城大学
2004年 - 2006年

電波天文観測用8Gサンプル/秒・超高速A/D変換LSIの開発
基盤研究(A)
国立天文台
2001年 - 2003年

結合型電波干渉計受信システムのための位相スイッチング方法に関する実証的研究
若手研究(B)
茨城大学
2001年 - 2002年

低質量原始星に付随するガスの高感度・高空間分解能観測
特別研究員奨励費
国立天文台
1999年 - 1999年

「原子力科学館リニューアル基本構想策定委員会」委員　　　　　　　　　　　　　　　
助言・指導
2017年11月01日 - 現在

高萩市立高萩小学校4年生に対する特別授業「オリオン座をみよう」　　　　　　　　　　　　　　　
講師
2024年01月25日 - 2024年01月25日

茨城県高等学校文化連盟・自然科学部会（2023冬合宿）講演　　　　　　　　　　　　　　　
講師
茨城県高等学校文化連盟・自然科学部会, 2023年11月11日 - 2023年11月11日

「つくばSKIPアカデミー」サイエンスキャンプ2023　　　　　　　　　　　　　　　
講師
2023年08月01日 - 2023年08月01日

アルマ望遠鏡本格運用開始10周年記念式典記念講演「惑星誕生の現場を探る：ALMAの10年，そして次のステージへ」　　　　　　　　　　　　　　　
講師
2023年05月17日 - 2023年05月17日

高萩市立東小学校4年生に対する特別授業「オリオン座をみよう」　　　　　　　　　　　　　　　
講師
2023年01月27日 - 2023年01月27日

「つくばSKIPアカデミー」サイエンスキャンプ2022　　　　　　　　　　　　　　　
講師
2022年08月01日 - 2022年08月01日

高萩市立秋山小学校4年生に対する特別授業「オリオン座をみよう」　　　　　　　　　　　　　　　
講師
2022年01月14日 - 2022年01月14日

高萩市立松岡小学校4年生に対する特別授業「オリオン座をみよう」　　　　　　　　　　　　　　　
講師
2020年01月16日 - 2020年01月16日

茨城県高等学校文化連盟・自然科学部会（2019冬合宿）講演　　　　　　　　　　　　　　　
講師
2019年12月21日 - 2019年12月21日

「つくばSKIPアカデミー」サイエンスキャンプ　　　　　　　　　　　　　　　
講師
2019年08月19日 - 2019年08月19日

国立天文台との協力で第10回公開天文台と講演会を企画・実施　　　　　　　　　　　　　　　
講師
2019年04月21日 - 2019年04月21日

いきいき萩っ子育成事業「望遠鏡製作体験講座」　　　　　　　　　　　　　　　
講師
2019年02月09日 - 2019年02月09日

いきいき萩っ子育成事業「冬の星空観望会」　　　　　　　　　　　　　　　
講師
2018年12月15日 - 2018年12月15日

放送大学学園祭講演　　　　　　　　　　　　　　　
講師
2018年10月14日 - 2018年10月14日

「つくばSKIPアカデミー」サイエンスキャンプ　　　　　　　　　　　　　　　
講師
2018年08月06日 - 2018年08月06日

国立天文台との協力で第9回公開天文台と講演会を企画・実施　　　　　　　　　　　　　　　
出演
2018年04月15日 - 2018年04月15日

いきいき萩っ子育成事業「冬の夜空の天体観望会」　　　　　　　　　　　　　　　
講師
2018年02月24日 - 2018年02月24日

いきいき萩っ子育成事業「望遠鏡製作体験講座」　　　　　　　　　　　　　　　
講師
2017年12月23日 - 2017年12月23日

ひたちなか市民大学講師　　　　　　　　　　　　　　　
講師
2017年11月01日 - 2017年11月29日

「つくばSKIPアカデミー」サイエンスキャンプ　　　　　　　　　　　　　　　
講師
2017年08月17日 - 2017年08月17日

第3回福島県高等学校理科研究活動講習会 全体講義　　　　　　　　　　　　　　　
講師
2017年05月03日 - 2017年05月03日

国立天文台との協力で第8回公開天文台と講演会を企画・実施　　　　　　　　　　　　　　　
出演
2017年04月16日 - 2017年04月16日

いきいき萩っ子育成事業「望遠鏡製作体験講座」　　　　　　　　　　　　　　　
講師
2017年02月04日 - 2017年02月04日

いきいき萩っ子育成事業「冬の夜空の天体観望会」　　　　　　　　　　　　　　　
講師
2016年12月03日 - 2016年12月03日

茨城県高等学校文化連盟・自然科学部会（冬合宿）講演　　　　　　　　　　　　　　　
講師
2016年12月03日 - 2016年12月03日

いきいき萩っ子育成事業・だいちの星座ポストイベント 「アンテナ、人工衛星、地上絵？」　　　　　　　　　　　　　　　
司会
2016年10月29日 - 2016年10月29日

県北芸術祭2016「だいちの星座プロジェクト・たかはぎ座撮影」への協力　　　　　　　　　　　　　　　
運営参加・支援
2016年08月11日 - 2016年08月11日

国立天文台との協力で第7回公開天文台と講演会を企画・実施　　　　　　　　　　　　　　　
出演
2016年04月17日 - 2016年04月17日

いきいき萩っ子育成事業「冬の夜空の天体観望会」　　　　　　　　　　　　　　　
講師
2016年03月13日 - 2016年03月13日

いきいき萩っ子育成事業「小学生の望遠鏡製作体験講座」　　　　　　　　　　　　　　　
講師
2016年01月20日 - 2016年01月20日

国立天文台との協力で第6回公開天文台と講演会を企画・実施　　　　　　　　　　　　　　　
出演
2015年04月19日 - 2015年04月19日

　　　「宇宙の不思議 解説」高萩小 茨城大学教授が出前授業　　　　　　　　　　　　　　　
茨城新聞社, 茨城新聞, 2024年02月02日, 新聞・雑誌

　　　「所さんの目がテン！」2月20日（日）オンエア（日本テレビ）出演　　　　　　　　　　　　　　　
日本テレビ他, 2022年02月20日, テレビ・ラジオ番組