Yoshinori YONEKURAProfessor

■Researcher basic information

Organization

  • College of Science  Director of Center for Astronomy
  • College of Science Department of Sciences Physics
  • Graduate School of Science and Engineering(Master's Program) Major in Science
  • Graduate School of Science and Engineerin(Doctoral Program) Major in Complex Systems Science
  • Faculty of Basic Natural Science Domain of Physics

Research Areas

  • Natural sciences, Astronomy, Astronomy

Research Keyword

  • Radio Astronomy, Star Formation

Degree

  • 1997年01月 博士(理学)(名古屋大学)
  • 1993年03月 修士(理学)(名古屋大学)

Educational Background

  • Apr. 1991 - Jan. 1997, Nagoya University, Graduate School of Science, Department of Astronomy
  • Apr. 1987 - Mar. 1991, Nagoya University, Faculty of Science, Department of Physics

Career

  • Apr. 2018, Professor
  • May 2009 - Mar. 2018, Associate Professor
  • Oct. 2008 - Apr. 2009, Associate Professor
  • Apr. 2006 - Sep. 2008, Lecturer
  • Apr. 2005 - Mar. 2006, Assistant Professor
  • Apr. 1998 - Mar. 2005, Assistant Professor
  • Aug. 1997 - Mar. 1998, 国立天文台 COE 研究員
  • Feb. 1997 - Mar. 1997, 日本学術振興会特別研究員(PD)
  • Apr. 1995 - Jan. 1997, 日本学術振興会特別研究員(DC)

Member History

  • Sep. 2022 - Aug. 2024, VLBI科学諮問委員会委員, National Astronomical Observatory of Japan
  • Aug. 2022 - Mar. 2024, 連携教授, 国立天文台
  • Apr. 2022 - Mar. 2024, 運営会議委員, National Astronomical Observatory of Japan
  • Sep. 2020 - Aug. 2022, VLBI科学諮問委員会委員, National Astronomical Observatory of Japan
  • Jul. 2020 - Jun. 2022, プロジェクト評価委員会委員, National Astronomical Observatory of Japan
  • Jul. 2019 - Mar. 2022, 連携教授, 国立天文台
  • Sep. 2018 - Aug. 2020, VLBI科学諮問委員会委員, National Astronomical Observatory of Japan
  • Jul. 2016 - Jun. 2020, 研究交流委員会委員, National Astronomical Observatory of Japan
  • Apr. 2018 - Mar. 2019, 連携教授, 国立天文台
  • Apr. 2018 - Mar. 2019, 客員教授, 宇宙航空研究開発機構
  • Apr. 2017 - Aug. 2018, 電波専門委員会VLBI小委員会委員, National Astronomical Observatory of Japan
  • Sep. 2016 - Aug. 2018, 電波専門委員会電波天文周波数小委員会委員, National Astronomical Observatory of Japan
  • Apr. 2017 - Mar. 2018, 連携准教授, 国立天文台
  • Apr. 2017 - Mar. 2018, 客員准教授, 宇宙航空研究開発機構
  • Apr. 2015 - Mar. 2017, 共同研究員, 国立天文台
  • Oct. 2008 - Mar. 2017, 電波専門委員会VLBI運営小委員会委員, National Astronomical Observatory of Japan
  • Aug. 2014 - Jul. 2016, 特別研究員等審査会専門委員及び国際事業委員会書面審査委員・書面評価員, 日本学術振興会
  • Apr. 2010 - Mar. 2015, 客員准教授, 国立天文台

■Research activity information

Paper

  • The candidates of long-periodic variable sources in 6.7 GHz methanol masers associated with four high-mass star-forming regions               
    Yoshihiro TANABE and Yoshinori YONEKURA
    Publ. Astron. Soc. Japan, Dec. 2024, [Reviewed]
  • An Ultra wide-band, high-sensitivity Q-band receiver for single-dish telescopes, eQ:,rest frequency determination of CCS (JN=43-32) and SO (JN=10-01), and high-redshift CO (J=1-0) detection               
    Fumitaka Nakamura; Chau-Ching Chiong; Kotomi Taniguchi; Chen Chien; Chin-Ting Ho; Yuh-Jing Hwang; You-Ting Yeh; Tomomi Shimoikura; Yasumasa Yamasaki; Sheng-Yuan Liu; Naomi Hirano; Shih-Ping Lai; Atsushi Nishimura; Ryohei Kawabe; Kazuhito Dobashi; Yasunori Fujii; Yoshinori Yonekura; and Hideo Ogawa
    Publ. Astron. Soc. Japan, Dec. 2024, [Reviewed]
  • Q-band line survey observations toward a carbon-chain-rich clump in the Serpens South region
    Kotomi Taniguchi; Fumitaka Nakamura; Sheng-Yuan Liu; Tomomi Shimoikura; Chau-Ching Chiong; Kazuhito Dobashi; Naomi Hirano; Yoshinori Yonekura; Hideko Nomura; Atsushi Nishimura; Hideo Ogawa; Chen Chien; Chin-Ting Ho; Yuh-Jing Hwang; You-Ting Yeh; Shih-Ping Lai; Yasunori Fujii; Yasumasa Yamasaki; Quang Nguyen-Luong; Ryohei Kawabe, Abstract

    We have conducted Q-band (30–50 GHz) line survey observations toward a carbon-chain emission peak in the Serpens South cluster-forming region with the extended Q-band (eQ) receiver installed on the Nobeyama 45 m radio telescope. Approximately 180 lines have been detected, including tentative detection, and these lines are attributed to 52 molecules including isotopologues. It has been found that this position is rich in carbon-chain species as much as Cyanopolyyne Peak in the Taurus Molecular Cloud-1 (TMC-1 CP), suggesting chemical youth. Not only carbon-chain species, but also several complex organic molecules (CH$_3$OH, CH$_3$CHO, HCCCHO, CH$_3$CN, and tentatively C$_2$H$_3$CN) have also been detected, which is similar to the chemical complexity found in evolved prestellar cores. The HDCS$/$H$_2$CS ratio has been derived to be $11.3\% \pm 0.5\%$, and this value is similar to the prestellar core L1544. The chemically young features that are similar to the less-dense starless core TMC-1 CP ($10^4$–$10^5\:$cm$^{-3}$) and chemically evolved characters which resemble the dense prestellar core L1544 (${\sim}10^6\:$cm$^{-3}$) mean that the clump including the observed position is a pre-cluster clump without any current star formation activity., Oxford University Press (OUP)
    Publications of the Astronomical Society of Japan, 08 Nov. 2024
  • Limits of water maser kinematics: insights from the high-mass protostar AFGL 5142-MM1
    Zulfazli Rosli; Ross A. Burns; Affan Adly Nazri; Koichiro Sugiyama; Tomoya Hirota; Kee-Tae Kim; Yoshinori Yonekura; Liu Tie; Gabor Orosz; James Okwe Chibueze; Andrey M. Sobolev; Ji Hyun Kang; Chang Won Lee; Jihye Hwang; Hafieduddin Mohammad; Norsiah Hashim and Zamri Zainal Abidin
    Monthly Notices of the Royal Astronomical Society, Feb. 2024, [Reviewed]
  • Modelling of the multitransition periodic flaring in G9.62+0.20E
    F. Rajabi; M. Houde; G.C. MacLeod; S. Goedhart; Y. Tanabe; S.P. van den Heever; C.M. Wyenberg and Y. Yonekura
    Monthly Notices of the Royal Astronomical Society, Nov. 2023, [Reviewed]
  • A kinematic study of the disc-outflow system around a high-mass protostar G59.783+0.065 probed by methanol and water masers
    M. Nakamura; K. Motogi; H. Nakamura; Y. Yonekura; K. Fujisawa
    Monthly Notices of the Royal Astronomical Society, Nov. 2023, [Reviewed]
  • Precessing jet nozzle connecting to a spinning black hole in M87
    Yuzhu Cui; Kazuhiro Hada; Tomohisa Kawashima; Motoki Kino; Weikang Lin; Yosuke Mizuno; Hyunwook Ro; Mareki Honma; Kunwoo Yi; Jintao Yu; Jongho Park; Wu Jiang; Zhiqiang Shen; Evgeniya Kravchenko; Juan-Carlos Algaba; Xiaopeng Cheng; Ilje Cho; Gabriele Giovannini; Marcello Giroletti; Taehyun Jung; Ru-Sen Lu; Kotaro Niinuma; Junghwan Oh; Ken Ohsuga; Satoko Sawada-Satoh; Bong Won Sohn; Hiroyuki R. Takahashi; Mieko Takamura; Fumie Tazaki; Sascha Trippe; Kiyoaki Wajima; Kazunori Akiyama; Tao An; Keiichi Asada; Salvatore Buttaccio; Do-Young Byun; Lang Cui; Yoshiaki Hagiwara; Tomoya Hirota; Jeffrey Hodgson; Noriyuki Kawaguchi; Jae-Young Kim; Sang-Sung Lee; Jee Won Lee; Jeong Ae Lee; Giuseppe Maccaferri; Andrea Melis; Alexey Melnikov; Carlo Migoni; Se-Jin Oh; Koichiro Sugiyama; Xuezheng Wang; Yingkang Zhang; Zhong Chen; Ju-Yeon Hwang; Dong-Kyu Jung; Hyo-Ryoung Kim; Jeong-Sook Kim; Hideyuki Kobayashi; Bin Li; Guanghui Li; Xiaofei Li; Zhiyong Liu; Qinghui Liu; Xiang Liu; Chung-Sik Oh; Tomoaki Oyama; Duk-Gyoo Roh; Jinqing Wang; Na Wang; Shiqiang Wang; Bo Xia; Hao Yan; Jae-Hwan Yeom; Yoshinori Yonekura; Jianping Yuan; Hua Zhang; Rongbing Zhao & Weiye Zhong, Springer Science and Business Media LLC
    Nature, 27 Sep. 2023, [Reviewed]
  • A Keplerian disk with a four-arm spiral birthing an episodically accreting high-mass protostar
    R.A. Burns; Y. Uno; N. Sakai; J. Blanchard; Z. Fazil; G. Orosz; Y. Yonekura; Y. Tanabe; K. Sugiyama; T. Hirota; Kee-Tae Kim; A. Aberfelds; A.E. Volvach; A. Bartkiewicz; A. Caratti o Garatti; A.M. Sobolev; B. Stecklum; C. Brogan; C. Phillips; D.A. Ladeyschikov; D. Johnstone; G. Surcis; G.C. MacLeod; H. Linz; J.O. Chibueze; J. Brand; J. Eislöffel; L. Hyland; L. Uscanga; M. Olech; M. Durjasz; O. Bayandina; S. Breen; S.P. Ellingsen; S.P. van den Heever; T.R. Hunter; X. Chen
    Nature Astronomy, May 2023, [Reviewed]
  • Detection of the longest periodic variability in 6.7 GHz methanol masers G5.900-0.430
    Y. Tanabe; Y. Yonekura; G.C. MacLeod
    Publ. Astron. Soc. Japan, Apr. 2023, [Reviewed]
  • Super-Resolved Image of M87 Observed with East Asian VLBI Network
    F. Tazaki; Y. Cui; K. Hada; M. Kino; I. Cho; G.-Y. Zhao; K. Akiyama; Y. Mizuno; H. Ro; M. Honma; R.-S. Lu; Z.-Q. Shen; L. Cui; Y. Yonekura, Obtaining high-resolution images at centimeter-or-longer wavelengths is vital for understanding the physics of jets. We reconstructed images from the M87 22 GHz data observed with the East Asian VLBI Network (EAVN) by using the regularized maximum likelihood (RML) method, which is different from the conventional imaging method CLEAN. Consequently, a bright core and jet extending about 30 mas to the northwest were detected with a higher resolution than in the CLEAN image. The width of the jet was 0.5 mas at 0.3 mas from the core, consistent with the width measured in the 86 GHz image in the previous study. In addition, three ridges were able to be detected at around 8 mas from the core, even though the peak-to-peak separation was only 1.0 mas. This indicates that the RML image's spatial resolution is at least 30% higher than that of the CLEAN image. This study is an important step for future multi-frequency and high-cadence observations of the EAVN to discuss the more detailed structure of the jet and its time variability., MDPI
    Galaxies, 28 Feb. 2023, [Reviewed]
  • Detection of a bright burst from the repeating FRB 20201124A at 2 GHz
    S. Ikebe; K. Takefuji; T. Terasawa; S. Eie; T. Akahori; Y. Murata; T. Hashimoto; S. Kisaka; M. Honma; S. Yoshiura; S. Suzuki; T. Oyama; M. Sekido; K. Niinuma; H. Takeuchi; Y. Yonekura; T. Enoto
    Publ. Astron. Soc. Japan, Feb. 2023, [Reviewed]
  • The Astrometric Animation of Water Masers towards the Mira Variable BX Cam
    S. Xu; H. Imai; Y.J. Yun; B. Zhang; M.J. Rioja; R. Dodson; S.-H. Cho; J.H. Kim; L. Cui; A.M. Sobolev; J.O. Chibueze; D.-J. Kim; K. Amada; J. Nakashima; G. Orosz; M. Oyadomari; S. Oh; Y. Yonekura; Y. Sun; X. Mai; J. Zhang; S. Wen; T. Jung
    Astrophys. J., 20 Dec. 2022, [Reviewed]
  • Overview of the Observing System and Initial Scientific Accomplishments of the East Asian VLBI Network (EAVN)
    K. Akiyama; J.-C. Algaba; T. An; K. Asada; K. Asanok; D.-Y. Byun; T. Chanapote; Z. Chen; W. Chen; X. Cheng; J.O. Chibueze; I. Cho; S.-H. Cho; H.-S. Chung; L. Cui; Y. Cui; A. Doi; J. Dong; K. Fujisawa; W. Gou; W. Guo; K. Hada; Y. Hagiwara; T. Hirota; J.A. Hodgson; M. Honma; H. Imai; P. Jaroenjittichai; W. Jiang; Y. Jiang; Y. Jiang; T. Jike; D.-K. Jung; T. Jung; N. Kawaguchi; D.-J. Kim; H.-R. Kim; J. Kim; J.-S. Kim; K.-T. Kim; S.-W. Kim; M. Kino; H. Kobayashi; S. Koyama; B.H. Kramer; J.-W. Lee; J.A. Lee; S.-S. Lee; S.W. Lee; B. Li; G. Li; X. Li; Z. Li; Q. Liu; X. Liu; R.-S. Lu; K. Motogi; M. Nakamura; K. Niinuma; C. Oh; H. Oh; J. Oh; S.-J. Oh; T. Oyama; J. Park; S. Poshyachinda; H. Ro; D.-G. Roh; W. Rujopakarn; N. Sakai; S. Sawada-Satoh; Z.-Q. Shen; K.M. Shibata; B.W. Sohn; B. Soonthornthum; K. Sugiyama; Y. Sun; M. Takamura; Y. Tanabe; F. Tazaki; S. Trippe; K. Wajima; J. Wang; N. Wang; S. Wang; X. Wang; B. Xia; S. Xu; H. Yan; W. Yang; J.-H. Yeom; K. Yi; S.-O. Yi; Y. Yonekura; H. Yoon; L. Yu; J. Yuan; Y. Yun; B. Zhang; H. Zhang; Y. Zhang; G.-Y. Zhao; R. Zhao; W. Zhong, The East Asian VLBI Network (EAVN) is an international VLBI facility in East Asia and is operated under mutual collaboration between East Asian countries, as well as part of Southeast Asian and European countries. EAVN currently consists of 16 radio telescopes and three correlators located in China, Japan, and Korea, and is operated mainly at three frequency bands, 6.7, 22, and 43 GHz with the longest baseline length of 5078 km, resulting in the highest angular resolution of 0.28 milliarcseconds at 43 GHz. One of distinct capabilities of EAVN is multi-frequency simultaneous data reception at nine telescopes, which enable us to employ the frequency phase transfer technique to obtain better sensitivity at higher observing frequencies. EAVN started its open-use program in the second half of 2018, providing a total observing time of more than 1100 h in a year. EAVN fills geographical gap in global VLBI array, resulting in enabling us to conduct contiguous high-resolution VLBI observations. EAVN has produced various scientific accomplishments especially in observations toward active galactic nuclei, evolved stars, and star-forming regions. These activities motivate us to initiate launch of the 'Global VLBI Alliance' to provide an opportunity of VLBI observation with the longest baselines on the earth., MDPI
    Galaxies, 07 Dec. 2022, [Reviewed]
  • The water and methanol masers in the face-on accretion system around the high-mass protostar G353.273+0.641
    Kazuhito Motogi; Tomoya Hirota; Masahiro N. Machida; Kei E. I. Tanaka; Yoshinori Yonekura, Abstract

    We report on a direct comparison of VLBI maser data and ALMA thermal-emission data for the high-mass protostar G353.273+0.641. We detected a gravitationally-unstable disk by dust and a high-velocity jet traced by a thermal CO line by ALMA long-baselines (LB). 6.7 GHz CH3OH masers trace infalling streamlines inside the disk. The innermost maser ring indicates another compact accretion disk of 30 au. Such a nested system could be caused by angular momentum transfer by the spiral arms. 22 GHz H2O masers trace the jet-accelerating region, which are directly connecting the CO jet and the protostar. The recurrent maser flares imply episodic jet ejections per 1–2 yr, while typical separation of CO knots indicates a variation of outflow rate per 100 yr. Our study demonstrates that VLBI maser observations are still a powerful tool to explore detailed structures nearby high-mass protostars by combining ALMA LB., Cambridge University Press (CUP)
    Proceedings of the International Astronomical Union, Dec. 2022
  • The Yamaguchi Interferometer
    K. Fujisawa; T. Aoki; S. Kanazawa; M. Akimoto; T. Ogura; K. Mori; K. Niinuma; K. Motogi; S. Sawada-Satoh; K. Takefuji; H. Ogawa; K. Kimura; Y. Yonekura; M. Honma
    Publ. Astron. Soc. Japan, Dec. 2022, [Reviewed]
  • Double-/triple-bands Simultaneous Observation System with Perforated Dichroic Filter Plates Equipped for the Nobeyama 45 m Radio Telescope
    Hiroshi Imai; Hideo Ogawa; Kotaro Niinuma; Yusuke Shimizu; Tomoaki Oyama; Chieko Miyazawa; Atsushi Nishimura; Chiaki Nosohara; Nozomi Okada; Kei Amada; Ren Matsusaka; Keisuke Nakashima; Ka-Yiu Shum; Toshikazu Takahashi; Toshihisa Tsutsumi; Sho Yoneyama; Satoko Sawada-Satoh; Hiroko Shinnaga; Yoshinori Yonekura; Tomoya Hirota; Seiji Kameno, IEEE
    2022 Asia-Pacific Microwave Conference (APMC), 29 Nov. 2022
  • Two periods instead of one in a single 6.7 GHz methanol maser feature in G9.62+0.20E
    G. C. MacLeod; Y. Yonekura; Y. Tanabe; W. A. Baan; C. L. Brogan; R. A. Burns; J. O. Chibueze; M. Houde; T. R. Hunter; S. E. Kurtz; F. Rajabi; D. P. Smits; B. Stecklum; and K. Sugiyama
    Monthly Notices of the Royal Astronomical Society, Oct. 2022, [Reviewed]
  • Millimeter methanol emission in the high-mass young stellar object G24.33+0.14
    T. Hirota; P. Wolak; T.R. Hunter; C.L. Brogan; A. Bartkiewicz; M. Durjasz; A. Kobak; M. Olech; M. Szymczak; R.A. Burns; A. Aberfelds; G. Baek; J. Brand; S. Breen; D.-Y. Byun; A. Caratti o Garatti; X. Chen; J.O. Chibueze; C. Cyganowski; J. Eislo ̈ffel; S. Ellingsen; N. Hirano; B. Hu; J.-H. Kang; J.-S. Kim; J. Kim; K.-T. Kim; M.K. Kim; B. Kramer; J.-E. Lee; H. Linz; T. Liu; G. MacLeod; T.P. McCarthy; K. Menten; K. Motogi; C.-S. Oh; G. Orosz; A.M. Sobolev; B. Stecklum; K. Sugiyama; K. Sunada; L. Uscanga; F. van den Heever; A.E. Volvach; L.N. Volvach; Y.W. Wu and Y. Yonekura, Abstract

    In 2019 September, a sudden flare of the 6.7 GHz methanol maser was observed toward the high-mass young stellar object (HMYSO) G24.33+0.14. This may represent the fourth detection of a transient mass accretion event in an HMYSO after S255IR NIRS3, NGC 6334I-MM1, and G358.93−0.03-MM1. G24.33+0.14 is unique among these sources as it clearly shows a repeating flare with an 8 yr interval. Using the Atacama Large Millimeter/submillimeter Array (ALMA), we observed the millimeter continuum and molecular lines toward G24.33+0.14 in the pre-flare phase in 2016 August (ALMA Cycle 3) and the mid-flare phase in 2019 September (ALMA Cycle 6). We identified three continuum sources in G24.33+0.14, and the brightest source, C1, which is closely associated with the 6.7 GHz maser emission, shows only a marginal increase in flux density with a flux ratio (Cycle 6$/$Cycle 3) of 1.16 ± 0.01, considering an additional absolute flux calibration uncertainty of $10\%$. We identified 26 transitions from 13 molecular species other than methanol, and they exhibit similar levels of flux differences with an average flux ratio of 1.12 ± 0.15. In contrast, eight methanol lines observed in Cycle 6 are brighter than those in Cycle 3 with an average flux ratio of 1.23 ± 0.13, and the higher excitation lines tend to show a larger flux increase. If this systematic increasing trend is real, it would suggest radiative heating close to the central HMYSO due to an accretion event which could expand the size of the emission region and/or change the excitation conditions. Given the low brightness temperatures and small flux changes, most of the methanol emission is likely to be predominantly thermal, except for the 229.759 GHz (8−1–70 E) line known as a class I methanol maser. The flux change in the millimeter continuum of G24.33+0.14 is smaller than in S255IR NIRS3 and NGC 6334I-MM1 but is comparable with that in G358.93−0.03-MM1, suggesting different amounts of accreted mass in these events., Oxford University Press (OUP)
    Publ. Astron. Soc. Japan, Oct. 2022, [Reviewed]
  • Mid-Infrared and Maser Flux Variability Correlation in Massive Young Stellar Object G036.70+00.09
    M. Uchiyama; K. Ichikawa; K. Sugiyama; Y. Tanabe and Y. Yonekura, We present the discovery of the simultaneous flux variation of a massive young stellar object (MYSO) G036.70+00.09 (G036.70) both in the maser emission and mid-infrared (MIR; lambda = 3-5 mu m) bands. Using the ALLWISE and NEOWISE archival databases that cover a long time span of approximately 10 yr with a cadence of 6 months, we confirm that G036.70 indicates a stochastic year-long MIR variability with no signs of a WISE band color change of W1 (3.4 mu m) -W2 (4.6 mu m). Cross-matching the MIR data set with the high-cadence 6.7 GHz class II methanol maser flux using the Hitachi 32 m radio telescope that discovered its periodicity in the methanol maser of 53.0-53.2 days, we also determine the flux correlations between the two bands at two different timescales, year-long and day-long, both of which have never been reported in MYSOs, except when they are in the accretion burst phase. The results of our study support the scenario that a class II methanol maser is pumped up by infrared emission from accreting disks of MYSOs. We also discuss the possible origins of MIR and maser variability. To explain the two observed phenomena, a stochastic year-long MIR variability with no signs of significant color change and maser-MIR variability correlation or a change in mass accretion rate and line-of-sight extinction because of the nonaxisymmetric dust density distribution in a rotating accretion disk are possible origins. Observations through spectroscopic monitoring of accretion-related emission lines are essential for determining the origin of the observed variability in G036.70., IOP Publishing Ltd
    Astrophys. J., 01 Sep. 2022, [Reviewed]
  • Extended Q-band (eQ) receiver for Nobeyama 45-m Telescope
    Chau-Ching Chiong; Fumitaka Nakamura; Atsushi Nishimura; Ross A. Burns; Chen Chien; Kazuhito Dobashi; Yasunori Fujii; Chin-Ting Ho; Yau De Huang; Yuh-Jing Hwang; Shou-Ting Jian; Ryohei Kawabe; Kimihiro Kimura; Sheng-Yuan Liu; Shih-Ping Lai; Hideo Ogawa; Nozomi Okada; Seiji Kameno; Tomomi Shimoikura; Shigehisa Takakuwa; Kotomi Taniguchi; Wei-Hao Wang; You-Ting Yeh; Yasumasa Yamasaki; Yoshinori Yonekura, SPIE
    Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI, 31 Aug. 2022
  • The evolution of the H2O maser emission in the accretion burst source G358.93-0.03
    O.S. Bayandina; C.L. Brogan; R.A. Burns; A. Caratti o Garatti; J.O. Chibueze; S.P. van den Heever; S.E. Kurtz; G.C. MacLeod; L. Moscadelli; A.M. Sobolev; K. Sugiyama; I.E. Val’tts; and Y. Yonekura
    Astron. Astrophys., Aug. 2022, [Reviewed]
  • The intrinsic structure of Sagittarius A* at 1.3 cm and 7 mm
    I. Cho; G.-Y. Zhao; T. Kawashima; M. Kino; K. Akiyama; M.D. Johnson; S. Issaoun; K. Moriyama; X. Cheng; J.-C. Algaba; T. Jung; B.W. Sohn; T.P. Krichbaum; M. Wielgus; K. Hada; R.-S. Lu; Y. Cui; S. Sawada-Satoh; Z. Shen; J. Park; W. Jiang; H. Ro; K. Yi; K. Wajima; J.W. Lee; J. Hodgson; F. Tazaki; M. Honma; K. Niinuma; S. Trippe; T. An; Y. Zhang; J.A. Lee; S.-J. Oh; D.-Y. Byun; S.-S. Lee; J.-Y. Kim; J. Oh; S. Koyama; K. Asada; X. Wang; L. Cui; Y. Hagiwara; M. Nakamura; M. Takamura; T. Hirota; K. Sugiyama; N. Kawaguchi; H. Kobayashi; T. Oyama; Y. Yonekura; J. Kim; J.-Y. Hwang; D.-K. Jung; H.-R. Kim; J.-S. Kim; C.-S. Oh; D.-G. Roh; J.-H. Yeom; B. Xia; W. Zhong; B. Li; R. Zhao; J. Wang; Q. Liu; Z. Chen, Abstract

    Sagittarius A* (Sgr A*), the Galactic Center supermassive black hole (SMBH), is one of the best targets in which to resolve the innermost region of an SMBH with very long baseline interferometry (VLBI). In this study, we have carried out observations toward Sgr A* at 1.349 cm (22.223 GHz) and 6.950 mm (43.135 GHz) with the East Asian VLBI Network, as a part of the multiwavelength campaign of the Event Horizon Telescope (EHT) in 2017 April. To mitigate scattering effects, the physically motivated scattering kernel model from Psaltis et al. (2018) and the scattering parameters from Johnson et al. (2018) have been applied. As a result, a single, symmetric Gaussian model well describes the intrinsic structure of Sgr A* at both wavelengths. From closure amplitudes, the major-axis sizes are ∼704 ± 102 μas (axial ratio ∼${1.19}_{-0.19}^{+0.24}$) and ∼300 ± 25 μas (axial ratio ∼1.28 ± 0.2) at 1.349 cm and 6.95 mm, respectively. Together with a quasi-simultaneous observation at 3.5 mm (86 GHz) by Issaoun et al. (2019), we show that the intrinsic size scales with observing wavelength as a power law, with an index ∼1.2 ± 0.2. Our results also provide estimates of the size and compact flux density at 1.3 mm, which can be incorporated into the analysis of the EHT observations. In terms of the origin of radio emission, we have compared the intrinsic structures with the accretion flow scenario, especially the radiatively inefficient accretion flow based on the Keplerian shell model. With this, we show that a nonthermal electron population is necessary to reproduce the source sizes., American Astronomical Society
    Astrophys. J.,, 20 Feb. 2022, [Reviewed]
  • A multi-transition methanol maser study of the accretion burst source G358.93-0.03-MM1               
    O.S. Bayandina; C.L. Brogan; R.A. Burns; X. Chen; T.R. Hunter; S.E. Kurtz; G.C. MacLeod; A.M. Sobolev; K. Sugiyama; I.E. Val’tts; and Y. Yonekura
    Astron. J., Feb. 2022, [Reviewed]
  • Molecular line search toward the flaring 6.7-GHz methanol masers of G 24.33+0.13 and G 359.62–0.24: rare maser transitions detected               
    T.P. McCarthy; G. Orosz; S.P. Ellingsen; S.L. Breen; M.A. Voronkov; R.A. Burns; M.Olech; Y. Yonekura; T. Hirota; P. Wolak; and L.J. Hyland
    Monthly Notices of the Royal Astronomical Society, Jan. 2022, [Reviewed]
  • Multi-frequency radio observations of the radio-loud magnetar XTE J1810-197
    S. Eie; T. Terasawa; T. Akahori; T. Oyama; T. Hirota; Y. Yonekura; T. Enoto; M. Sekido; K. Takefuji; H. Misawa; F. Tsuchiya; S. Kisaka; T. Aoki; M. Honma, Abstract
    We report on the multi-frequency multi-epoch radio observations of the magnetar XTE J1810−197, which exhibited a radio outburst from 2018 December after its 10-year quiescent period. We performed quasi-simultaneous observations with VERA (22 GHz), Hitachi (6.9 GHz and 8.4 GHz), Kashima (2.3 GHz), and Iitate (0.3 GHz) radio telescopes located in Japan to trace the variability of the magnetar radio pulsations during the observing period from 2018 December 13 to 2019 June 12. The pulse width becomes narrower as the observing frequency goes higher, analogous to the general profile narrowing behavior of ordinary pulsars. When assuming a simple power law in the range of 2.3 GHz and 8.7 GHz, the radio spectrum of the magnetar goes steeper with the average spectral index 〈α〉 ≈ −0.85 for the first four months. The wide-band radio spectra gathered from our observations and the literature suggest that XTE J1810−197 would have a double-peaked spectrum with a valley point in 22–150 GHz, where the first spectral peak implies a gigahertz-peaked spectrum (GPS) feature with a peak at a few GHz. The GPS and the high-frequency peak have been identified in the spectra of other radio-loud magnetars, thus they may be intrinsic features that can give a new insight to the understanding of various emission mechanisms and the surrounding environments of radio magnetars. Our study emphasizes the importance of simultaneous long-term broad-band observations toward radio-loud magnetars to capture the puzzling spectral features and establish a link to other types of neutron stars., Oxford University Press (OUP)
    Publ. Astron. Soc. Japan, Dec. 2021, [Reviewed]
  • Measuring the impact of Indonesian antennas on global geodetic VLBI network
    I. N. Huda; T. Hidayat; B. Dermawan; S. Lambert; N. Liu; S. Leon; K. Fujisawa; Y. Yonekura; K. Sugiyama; T. Hirota; P. W. Premadi; R. Breton; Y.-C. Minh; P. Jaroenjittichai; D. Wijaya; D. Pradipta; N. S. E. Putri; S. Ramadhan; L. Puspitarini; H. R. T. Wulandari and M. Hafieduddin, Springer Science and Business Media LLC
    Exp. Astronomy, Oct. 2021, [Reviewed]
  • East Asian VLBI Network Observations of Active Galactic Nuclei Jets: Imaging with KaVA+Tianma+Nanshan
    Y.-Z. Cui; K. Hada; M. Kino; B.-W. Sohn; J. Park; H.-W. Ro; S. Sawada-Satoh; W. Jiang; L. Cui; M. Honma; Z.-Q. Shen; F. Tazaki; T. An; I. Cho; G.-Y. Zhao; X.-P. Cheng; K. Niinuma; K. Wajima; Y.-K. Zhang; N. Kawaguchi; J.-C. Algaba; S. Koyama; T. Hirota; Y. Yonekura; N. Sakai; B. Xia; Y.-B. Jiang; L.-F. Yu; W. Gou; J.-Y. Hwang; Y.-C. Jiang; Y.-X. Sun; D.-K. Jung; H.-R. Kim; J.-S. Kim; H. Kobayashi; J.-W. Lee; J.-A. Lee; H. Zhang; G.-H. Li; Z.-Q. Xu; P. Li; J.-H. Oh; S.-J. Oh; C.-S. Oh; T. Oyama; D.-G. Roh; K.M. Shibata; W. Guo; R.-B. Zhao; W.-Y. Zhong; J.-Q. Wang; W.-J. Yang; H. Yan; J.-H. Yeom; B. Li; X.-F. Li; J.-P. Yuan; J. Dong; Z. Chen; K. Akiyama; K. Asada; D.-Y. Byun; Y. Hagiwara; J. Hodgson; T.-H. Jung; K.-T. Kim; S.-S. Lee; K. Yi; Q.-H. Liu; X. Liu; R.-S. Lu; M. Nakamura; S. Trippe; N. Wang; X.-Z. Wang; B. Zhang, IOP Publishing
    Research in Astronomy and Astrophysics, Aug. 2021, [Reviewed]
  • Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
    J.C. Algaba et al., Abstract
    In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109
    M
    . The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded., American Astronomical Society
    Astrophys. J. Letter, 14 Apr. 2021, [Reviewed]
  • Discovery of X-ray Enhancement Coinciding with Giant Radio Pulses from the Crab Pulsar
    T. Enoto; T. Terasawa; S. Kisaka; C.-P. Hu; S. Guillot; N. Lewandowska; C. Malacaria; P.S. Ray; W.C.G. Ho; A.K. Harding; T. Okajima; Z. Arzoumanian; K.C. Gendreau; Z. Wadiasingh; C.B. Markwardt; Y. Soong; S. Kenyon; S. Bogdanov; W.A. Majid; T. Guver; G.K. Jaisawal; R. Foster; Y. Murata; H. Takeuchi; K. Takefuji; M. Sekido; Y. Yonekura; H. Misawa; F. Tsuchiya; T. Aoki; M. Tokumaru; M. Honma; O. Kameya; T. Oyama; K. Asano; S. Shibata and S.J. Tanaka, Giant radio pulses (GRPs) are sporadic bursts emitted by some pulsars that last a few microseconds and are hundreds to thousands of times brighter than regular pulses from these sources. The only GRP-associated emission outside of radio wavelengths is from the Crab Pulsar, where optical emission is enhanced by a few percentage points during GRPs. We observed the Crab Pulsar simultaneously at x-ray and radio wavelengths, finding enhancement of the x-ray emission by 3.8 ± 0.7% (a 5.4σ detection) coinciding with GRPs. This implies that the total emitted energy from GRPs is tens to hundreds of times higher than previously known. We discuss the implications for the pulsar emission mechanism and extragalactic fast radio bursts.
    Science, 09 Apr. 2021, [Reviewed]
  • Water maser variability in a high-mass YSO outburst: VERA and ALMA observations of S255 NIRS 3
    T. Hirota; R. Cesaroni; L. Moscadelli; K. Sugiyama; R.A. Burns; J. Kim; K. Sunada; and Y. Yonekura
    Astron. Astrophys., Mar. 2021, [Reviewed]
  • Infrared observations of the flaring maser source G358.93−0.03: SOFIA confirms an accretion burst from a massive young stellar object
    B. Stecklum; V. Wolf; H. Linz; A. Caratti o Garatti; S. Schmidl; S. Klose; J. Eislöffel; Ch. Fischer; C. Brogan; R. Burns; O. Bayandina; C. Cyganowski; M. Gurwell; T. Hunter; N. Hirano; K.-T. Kim; G. MacLeod; K. M. Menten; M. Olech; G. Orosz; A. Sobolev; T. K. Sridharan; G. Surcis; K. Sugiyama; J. van der Walt; A. Volvach; and Y. Yonekura
    Astron. Astrophys., Feb. 2021, [Reviewed]
  • Development of a 6.5-22.5 GHz very wide band feed antenna using a new Quadruple-Ridged Antenna for the traditional radio telescopes               
    Y. Hasegawa; Y. Yamasaki; H. Ogawa; T. Kawakami; Y. Yonekura; K. Kimura; T. Akahori; M. Ishino; Y. Kawahara
    IVS NICT Technology Development Center NEWS, Jan. 2021
  • A Search for Compact Radio Sources Toward the Center of the Galaxy               
    Sachi Sukehiro; Kenta Fujisawa; and Yoshinori Yonekura
    New Horizons in Galactic Center Astronomy and Beyond (eds. Masato Tsuboi and Tomoharu Oka), ASP Conference Series, Vol. 528, Proceedings of a workshop held 21-24 October 2019 at Keio University, Yokohama, Japan (San Francisco: Astronomical Society of the Pacific)., Jul. 2020
  • Near-infrared monitoring of the accretion outburst in the massive young stellar object S255-NIRS3
    Mizuho Uchiyama; Takuya Yamashita; Koichiro Sugiyama; Tatsuya Nakaoka; Miho Kawabata; Ryosuke Itoh; Masayuki Yamanaka; Hiroshi Akitaya; Koji Kawabata; Yoshinori Yonekura; Yu Saito; Kazuhito Motogi and Kenta Fujisawa, Abstract

    We followed up the massive young stellar object S255-NIRS3 (= S255-IRS1b) during its recent accretion outburst event in the $K_{\rm s}$ band with Kanata/HONIR for four years after its burst and obtained a long-term light curve. This is the most complete near-infrared light curve of the S255-NIRS3 burst event that has ever been presented. The light curve showed a steep increase reaching a peak flux that was 3.4 mag brighter than the quiescent phase and then a relatively moderate year-scale fading until the last observation, similar to that of the accretion burst events such as EXors found in lower-mass young stellar objects. The behavior of the $K_{\rm s}$-band light curve is similar to that observed in 6.7 GHz class II methanol maser emission, with a sudden increase followed by moderate year-scale fading. However, the maser emission peaks appear 30–50 d earlier than that of the $K_{\rm s}$ band emission. The similarities confirmed that the origins of the maser emission and the $K_{\rm s}$-band continuum emission are common, as previously shown from other infrared and radio observations by Stecklum et al. (2016, Astronomer’s Telegram, 8732), Caratti o Garatti et al. (2017b, Nature Phys., 13, 276), and Moscadelli et al. (2017, A&A, 600, L8). However, the differences in energy transfer paths, such as the exciting/emitting/scattering structures, may cause the delay in the flux-peak dates., Oxford University Press (OUP)
    Publ. Astron. Soc. Japan, 25 Feb. 2020, [Reviewed]
  • A heatwave of accretion energy traced by masers in the G358-MM1 high-mass protostar
    R. A. Burns; K. Sugiyama; T. Hirota; Kee-Tae. Kim; A. M. Sobolev; B. Stecklum; G. C. MacLeod; Y. Yonekura; M. Olech; G. Orosz; S. P. Ellingsen; L. Hyland; A. Caratti o Garatti; C. Brogan; T. Hunter; C. Philips; S. P. van den Heever; J. Eislöffe; H. Linz; G. Surcis; J. O. Chibueze; W. Baan and B. Kramer
    Nature Astronomy, 13 Jan. 2020, [Reviewed]
  • VLBI at 230 GHz using SPART toward EHT and EAVN -hi-               
    T. Aoki; H. Maezawa; S. Masui; D. Tsukiyama; A. Tomihara; N. Okada; A. Nishimura; H. Ogawa; K. Niinuma; R. Amari; T. Tsutsumi; K. Fujisawa; Y. Yonekura; Y. Kamichi; and M. Inoue
    IVS NICT Technology Development Center NEWS, Dec. 2019
  • The VLBI survey of Extremely Compact HII regions associated with a high mass star just after nuclear ignition using Kashima - Hitachi baseline               
    T. Ogura; K. Motogi; T. Aoki; K. Niinuma; K. Fujisawa; Y. Yonekura; M. Sekido; and K. Takefuji
    IVS NICT Technology Development Center NEWS, Dec. 2019
  • Ten years of Ibaraki Station               
    Y. Yonekura
    IVS NICT Technology Development Center NEWS, Dec. 2019
  • Detection of new methanol maser transitions associated with G358.93-0.03
    G. C. MacLeod; K. Sugiyama; T. R. Hunter; J. Quick; W. Baan; S. L. Breen; C. L. Brogan; R. A. Burns; X. Chen; J. O. Chibueze; M. Houde; J. F. Kaczmarek; H. Linz; F. Rajabi; Y. Saito; S. Schmidl; A. M. Sobolev; B. Stecklum; S. P. van den Heever; and Y. Yonekura
    Monthly Notices of the Royal Astronomical Society, Nov. 2019, [Reviewed]
  • The Galactic Center Lobe Filled with Thermal Plasma
    Halca NAGOSHI; Yuzo KUBOSE; Kenta FUJISAWA; Kazuo SORAI; Yoshinori YONEKURA; Koichiro SUGIYAMA; Kotaro NIINUMA; Kazuhito MOTOGI; and Takahiro AOKI
    Publ. Astron. Soc. Japan, 25 Aug. 2019, [Reviewed]
  • The First bird's-eye View of the Gravitationally Unstable Accretion Disk in High Mass Star-formation
    Kazuhito Motogi; Tomoya Hirota; Masahiro N. Machida; Yoshinori Yonekura; Mareki Honma; Shigehisa Takakuwa; and Satoki Matsushita
    Astrophys. J. Letter, 01 Jun. 2019, [Reviewed]
  • A balloon-borne very long baseline interferometry experiment in the stratosphere: Systems design and developments
    Akihiro Doi; Yusuke Kono; Kimihiro Kimura; Satomi Nakahara; Tomoaki Oyama; Nozomi Okada; Yasutaka Satou; Kazuyoshi Yamashita; Naoko Matsumoto; Mitsuhisa Baba; Daisuke Yasuda; Shunsaku Suzuki; Yutaka Hasegawa; Mareki Honma; Hiroaki Tanaka; Kosei Ishimura; Yasuhiro Murata; Reiho Shimomukai; Tomohiro Tachi; Kazuya Saito; Naohiko Watanabe; Nobutaka Bando; Osamu Kameya; Yoshinori Yonekura; Mamoru Sekido; Yoshiyuki Inoue; Hiraku Sakamoto; Nozomu Kogiso; Yasuhiro Shoji; Hideo Ogawa; Kenta Fujisawa; Masanao Narita; Hiroshi Shibai; Hideyuki Fuke; Kenta Uehara; Shoko Koyama, Elsevier BV
    Advances in Space Research, Jan. 2019, [Reviewed]
  • Performance evaluation of Usuda Deep Space Center 64 m antenna for radio astronomical observations and efforts on its improvement               
    藏原 昂平; 中西 裕之; 村田 泰宏; 上原 顕太; 青木 貴弘; 今井 裕; 藤沢 健太; 米倉 覚則
    Rep. Fac. Sci., Kagoshima Univ., 31 Dec. 2018
  • Long-term and highly frequent monitor of 6.7 GHz methanol masers to statistically research periodic flux variations around high-mass protostars using the Hitachi 32-m
    K. Sugiyama; Y. Yonekura; K. Motogi; Y. Saito; T. Yamaguchi; M. Momose; M. Honma; T. Hirota; M. Uchiyama; N. Matsumoto; K. Hachisuka; K. Inayoshi; K.E.I. Tanaka; T. Hosokawa; K. Fujisawa
    Astrophysical Masers: Unlocking the Mysteries of the Universe, Proceedings of the International Astronomical Union, IAU Symposium, Volume 336, Aug. 2018
  • A Face-on Accretion System in High Mass Star-Formation: Possible Dusty Infall Streams within 100 Astronomical Unit
    K. Motogi; T. Hirota; K. Sorai; Y. Yonekura; K. Sugiyama; M. Honma; K. Niinuma; K. Hachisuka; K. Fujisawa; A.J. Walsh, We report on interferometric observations of a face-on accretion system around the High-Mass young stellar object, G353.273+0.641. The innermost accretion system of 100 au radius was resolved in a 45 GHz continuum image taken with the Jansky-Very Large Array. Our spectral energy distribution analysis indicated that the continuum could be explained by optically thick dust emission. The total mass of the dusty system is $\sim$ 0.2 $M_{\sun}$ at minimum and up to a few $M_{\sun}$ depending on the dust parameters. 6.7 GHz CH$_{3}$OH masers associated with the same system were also observed with the Australia Telescope Compact Array. The masers showed a spiral-like, non-axisymmetric distribution with a systematic velocity gradient. The line-of-sight velocity field is explained by an infall motion along a parabolic streamline that falls onto the equatorial plane of the face-on system. The streamline is quasi-radial and reaches the equatorial plane at a radius of 16 au. This is clearly smaller than that of typical accretion disks in High-Mass star formation, indicating that the initial angular momentum was very small, or the CH$_{3}$OH masers selectively trace accreting material that has small angular momentum. In the former case, the initial specific angular momentum is estimated to be 8 $\times$ 10$^{20}$ ($M_{*}$$/$10 $M_{\sun}$)$^{0.5}$ cm$^{2}$ s$^{-1}$, or a significant fraction of the initial angular momentum was removed outside of 100 au. The physical origin of such a streamline is still an open question and will be constrained by the higher-resolution ($\sim$ 10 mas) thermal continuum and line observations with ALMA long baselines.
    Astrophysical Masers: Unlocking the Mysteries of the Universe, Proceedings of the International Astronomical Union, IAU Symposium, Volume 336, Aug. 2018
  • 6.7 GHz Methanol Masers Observation with Phased Hitachi and Takahagi
    K. Takefuji; K. Sugiyama; Y. Yonekura; T. Saito; K. Fujisawa; T. Kondo
    Astrophysical Masers: Unlocking the Mysteries of the Universe, Proceedings of the International Astronomical Union, IAU Symposium, Volume 336, Aug. 2018
  • A comparative study of amplitude calibrations for the East Asia VLBI Network: A priori and template spectrum methods
    Ilje Cho; Taehyun Jung; Guang-Yao Zhao; Kazunori Akiyama; Satoko Sawada-Satoh; Motoki Kino; Do-Young Byun; Bong Won Sohn; Katsunori M. Shibata; Tomoya Hirota; Kotaro Niinuma; Yoshinori Yonekura; Kenta Fujisawa; and Tomoaki Oyama, We present the results of comparative study of amplitude calibrations for East-Asia VLBI Network (EAVN) at 22 and 43 GHz using two different methods of an "a-priori" and a "template spectrum", particularly on lower declination sources. Using observational data sets of early EAVN observations, we investigated the elevation-dependence of the gain values at seven stations of the KaVA (KVN and VERA Array) and three additional telescopes in Japan (Takahagi 32m, Yamaguchi 32m and Nobeyama 45m). By comparing the independently obtained gain values based on these two methods, we found that the gain values from each method were consistent within 10% at elevations higher than 10 degree. We also found that the total flux densities of two images produced from the different amplitude calibrations were in agreement within 10% at both 22 and 43 GHz. By using the template spectrum method, furthermore, the additional radio telescopes can participate in the KaVA (i.e. EAVN) so that it can give a notable sensitivity increase. Therefore, our results will constrain the detailed conditions to reliably measure the VLBI amplitude using EAVN and give a potential to extend possible telescopes comprising EAVN.
    Publ. Astron. Soc. Japan, 25 Dec. 2017, [Reviewed]
  • A Face-on Accretion System in High-mass Star Formation: Possible Dusty Infall Streams within 100 AU               
    Kazuhito Motogi; Tomoya Hirota; Kazuo Sorai; Yoshinori Yonekura; Koichiro Sugiyama; Mareki Honma; Kotaro Niinuma; Kazuya Hachisuka; Kenta Fujisawa; and Andrew J. Walsh
    Astrophys. J., 01 Nov. 2017, [Reviewed]
  • Development of the Phase-up Technology of the Radio Telescopes: 6.7 GHz Methanol Maser Observations with Phased Hitachi 32 m and Takahagi 32 m Radio Telescopes               
    Kazuhiro Takefuji; Koichiro Sugiyama; Yoshinori Yonekura; Tagiru Saito; Kenta Fujisawa; Tetsuro Kondo
    Publ. Astron. Soc. Pacific, Nov. 2017, [Reviewed]
  • OISTER Optical and Near-Infrared Monitoring Observations of a Peculiar Radio-Loud Active Galactic Nucleus SDSS J110006.07+442144.3
    Tomoki Morokuma; Masaomi Tanaka; Yasuyuki T. Tanaka; Ryosuke Itoh; Nozomu Tominaga; Poshak Gandhi; Elena Pian; Paolo Mazzali; Kouji Ohta; Emiko Matsumoto; Takumi Shibata; Hinako Akimoto; Hiroshi Akitaya; Gamal B. Ali; Tsutomu Aoki; Mamoru Doi; Nana Ebisuda; Ahmed Essam; Kenta Fujisawa; Hideo Fukushima; Shuhei Goda; Yuya Gouda; Hidekazu Hanayama; Yasuhito Hashiba; Osamu Hashimoto; Kenzo Hayashida; Yuichiro Hiratsuka; Satoshi Honda; Masataka Imai; Kanichiro Inoue; Michiko Ishibashi; Ikuru Iwata; Hideyuki Izumiura; Yuka Kanda; Miho Kawabata; Kenji Kawaguchi; Nobuyuki Kawai; Mitsuru Kokubo; Daisuke Kuroda; Hiroyuki Maehara; Hiroyuki Mito; Kazuma Mitsuda; Ryota Miyagawa; Takeshi Miyaji; Yusuke Miyamoto; Kumiko Morihana; Yuki Moritani; Kana Morokuma-Matsui; Kotone Murakami; Katsuhiro L. Murata; Takahiro Nagayama; Kazuki Nakamura; Tatsuya Nakaoka; Kotaro Niinuma; Takafumi Nishimori; Daisaku Nogami; Yumiko Oasa; Tatsunori Oda; Tomohito Ohshima; Yoshihiko Saito; Shuichiro Sakata; Shigeyuki Sako; Yuki Sarugaku; Satoko Sawada-Satoh; Genta Seino; Kazuo Sorai; Takao Soyano; Francesco Taddia; Jun Takahashi; Yuhei Takagi; Katsutoshi Takaki; Koji Takata; Ken’ichi Tarusawa; Makoto Uemura; Takahiro Ui; Riku Urago; Kazutoshi Ushioda; Jun-Ichi Watanabe; Makoto Watanabe; Satoshi Yamashita; Kenshi Yanagisawa; Yoshinori Yonekura and Michitoshi Yoshida, We present monitoring campaign observations at optical and near-infrared (NIR) wavelengths for a radio-loud active galactic nucleus (AGN) at z = 0.840, SDSS J110006.07+442144.3 (hereafter, J1100+4421), which was identified during a flare phase in late 2014 February. The campaigns consist of three intensive observing runs from the discovery to 2015 March, mostly within the scheme of the OISTER collaboration. Optical-NIR light curves and simultaneous spectral energy distributions (SEDs) are obtained. Our measurements show the strongest brightening in 2015 March. We found that the optical-NIR SEDs of J1100+4421 show an almost steady shape despite the large and rapid intranight variability. This constant SED shape is confirmed to extend to ∼5 μm in the observed frame using the archival WISE data. Given the lack of absorption lines and the steep power-law spectrum of α ν ∼ -1.4, where fνναν, synchrotron radiation by a relativistic jet with no or small contributions from the host galaxy and the accretion disk seems most plausible as an optical-NIR emission mechanism. The steep optical-NIR spectral shape and the large amplitude of variability are consistent with this object being a low ν peak jet-dominated AGN. In addition, sub-arcsecond resolution optical imaging data taken with Subaru Hyper Suprime-Cam does not show a clear extended component and the spatial scales are significantly smaller than the large extensions detected at radio wavelengths. The optical spectrum of a possible faint companion galaxy does not show any emission lines at the same redshift, and hence a merging hypothesis for this AGN-related activity is not supported by our observations., Oxford University Press
    Publ. Astron. Soc. Japan, 25 Oct. 2017, [Reviewed]
  • 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; and 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
    Publ. Astron. Soc. Japan, 25 Aug. 2017, [Reviewed]
  • HCN hyperfine ratio analysis of massive molecular clumps
    W. J. Schap; P. J. Barnes; A. Ordñez; A. Ginsburg; Y. Yonekura; Y. Fukui, We report a new analysis protocol for HCN hyperfine data, based on the PYSPECKIT package, and results of using this new protocol to analyse a sample area of seven massive molecular clumps from the Census of High- and Medium-mass Protostars (CHaMP) survey, in order to derive maps of column density for this species. There is a strong correlation between the HCN integrated intensity, IHCN, and previously reported IHCO+ in the clumps, but IN2H+ is not well correlated with either of these other two 'dense gas tracers'. The four fitted parameters from PYSPECKIT in this region fall in the range of VLSR = 8-10 km s-1, σV = 1.2-2.2 km s-1, Tex = 4-15 K, and τ = 0.2-2.5. These parameters allow us to derive a column density map of these clouds, without limiting assumptions about the excitation or opacity. A more traditional (linear) method of converting IHCN to total mass column gives much lower clump masses than our results based on the hyperfine analysis. This is primarily due to areas in the sample region of low I, lowTex, and high τ. We conclude that there may be more dense gas in these massive clumps not engaged in massive star formation than previously recognized. If this result holds for other clouds in the CHaMP sample, it would have dramatic consequences for the calibration of the Kennicutt-Schmidt star formation laws, including a large increase in the gas depletion time-scale in such regions., Oxford University Press
    Monthly Notices of the Royal Astronomical Society, 2017, [Reviewed]
  • Wide-Band Spectra of Giant Radio Pulses from the Crab Pulsar
    Ryo Mikami; Katsuaki Asano; Shuta J. Tanaka; Shota Kisaka; Mamoru Sekido; Kazuhiro Takefuji; Hiroshi Takeuchi; Hiroaki Misawa; Fuminori Tsuchiya; Hajime Kita; Yoshinori Yonekura; and Toshio Terasawa, © 2016. The American Astronomical Society. All rights reserved.. We present the results of the simultaneous observation of giant radio pulses (GRPs) from the Crab pulsar at 0.3, 1.6, 2.2, 6.7, and 8.4 GHz with four telescopes in Japan. We obtain 3194 and 272 GRPs occurring at the main pulse and the interpulse phases, respectively. A few GRPs detected at both 0.3 and 8.4 GHz are the most wide-band samples ever reported. In the frequency range from 0.3 to 2.2 GHz, we find that about 70% or more of the GRP spectra are consistent with single power laws and their spectral indices are distributed from -4 to -1. We also find that a significant number of GRPs have such a hard spectral index (approximately -1) that the fluence at 0.3 GHz is below the detection limit ("dim-hard" GRPs). Stacking light curves of such dim-hard GRPs at 0.3 GHz, we detect consistent enhancement compared to the off-GRP light curve. Our samples show apparent correlations between the fluences and the spectral hardness, which indicates that more energetic GRPs tend to show softer spectra. Our comprehensive studies on the GRP spectra are useful materials to verify the GRP model of fast radio bursts in future observations.
    Astrophys. J., 01 Dec. 2016, [Reviewed]
  • The Hitachi and Takahagi 32 m radio telescopes: Upgrade of the antennas from satellite communication to radio astronomy
    Yoshinori Yonekura; Yu Saito; Koichiro Sugiyama; Kang Lou Soon; Munetake Momose; Masayoshi Yokosawa; Hideo Ogawa; Kimihiro Kimura; Yasuhiro Abe; Atsushi Nishimura; Yutaka Hasegawa; Kenta Fujisawa; Tomoaki Ohyama; Yusuke Kono; Yusuke Miyamoto; Satoko Sawada-Satoh; Hideyuki Kobayashi; Noriyuki Kawaguchi; Mareki Honma; Katsunori M. Shibata; Katsuhisa Sato; Yuji Ueno; Takaaki Jike; Yoshiaki Tamura; Tomoya Hirota; Atsushi Miyazaki; Kotaro Niinuma; Kazuo Sorai; Hiroshi Takaba; Kazuya Hachisuka; Tetsuro Kondo; Mamoru Sekido; Yasuhiro Murata; Naomasa Nakai; and Toshihiro Omodaka, Lead, 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
    Publ. Astron. Soc. Japan, 25 Oct. 2016, [Reviewed]
  • Observations of 6.7 GHz methanol masers with East-Asian VLBI Network. II. Internal proper motion measurement in G 006.79−00.25
    Koichiro Sugiyama; Kenta Fujisawa; Kazuya Hachisuka; Yoshinori Yonekura; Kazuhito Motogi; Satoko Sawada-Satoh; Naoko Matsumoto; Daiki Hirano; Kyonosuke Hayashi; Hideyuki Kobayashi; Noriyuki Kawaguchi; Katsunori M. Shibata; Mareki Honma; Tomoya Hirota; Yasuhiro Murata; Akihiro Doi; Hideo Ogawa; Kimihiro Kimura; Kotaro Niinuma; Xi Chen; Bo Xia; Bin Li; Kazuo Sorai; Munetake Momose; Yu Saito; Hiroshi Takaba; Toshihiro Omodaka; Kee-Tae Kim; and Zhiqiang Shen
    Publ. Astron. Soc. Japan, 25 Oct. 2016, [Reviewed]
  • Accelerating a water maser face-on jet from a high mass young stellar object
    Kazuhito Motogi; Kazuo Sorai; Mareki Honma; Tomoya Hirota; Kazuya Hachisuka; Kotaro Niinuma; Koichiro Sugiyama; Yoshinori Yonekura; Kenta Fujisawa, We report on a long-term single-dish and VLBI monitoring for intermittent flare activities of a Dominant Blue-Shifted H$_{2}$O Maser (DBSM) associated with a southern high mass young stellar object, G353.273+0.641. Bi-weekly single-dish monitoring using Hokkaido University Tomakomai 11-m radio telescope has shown that a systematic acceleration continues over four years beyond a lifetime of individual maser features. This fact suggests that the H$_{2}$O maser traces a region where molecular gas is steadily accelerated. There were five maser flares during five-years monitoring, and maser distributions in four of them were densely monitored by the VLBI Exploration of Radio Astrometry (VERA). The overall distribution of the maser features suggests the presence of a bipolar jet, with the 3D kinematics indicating that it is almost face-on (inclination angle of $\sim$ 8$^{\fdg}$--17$^{\fdg}$ from the line-of-sight). Most of maser features were recurrently excited within a region of 100$\times$100 AU$^{2}$ around the radio continuum peak, while their spatial distributions significantly varied between each flare. This confirms that episodic propagations of outflow shocks recurrently invoke intermittent flare activities. We also measured annual parallax, deriving the source distance of 1.70 $^{+0.19}_{-0.16}$ kpc that is consistent with the commonly-used photometric distance.
    Publ. Astron. Soc. Japan, 25 Oct. 2016, [Reviewed]
  • Z45: A New 45-GHz band dual-polarization HEMT receiver for the NRO 45-m radio telescope
    Fumitaka Nakamura; Hideo Ogawa; Yoshinori Yonekura; Kimihiko Kimura; Nozomi Okada; Minato Kozu; Yutaka Hasegawa; Kazuki Tokuda; Tetsu Ochiai; Izumi Mizuno; Kazuhito Dobashi; Tomomi Shimoikura; Seiji Kameno; Kotomi Taniguchi; Hiroko Shinnaga; Shuro Takano; Ryohei Kawabe; Taku Nakajima; Daisuke Iono; Nario Kuno; Toshikazu Onishi; Munetake Momose; and Satoshi Yamamoto
    Publ. Astron. Soc. Japan, 25 Dec. 2015, [Reviewed]
  • 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, Sep. 2015, [Reviewed]
  • No Microwave Flare of Sagittarius A* around the G2 Periastron Passing               
    Masato Tsuboi; Yoshiharu Asaki; Osamu Kameya; Yoshinori Yonekura; Yusuke Miyamoto; Hiroyuki Kaneko; Masumichi Seta; Naomasa Nakai; Hiroshi Takaba; Ken-ichi Wakamatsu; Makoto Miyoshi; Yoshihiro Fukuzaki; Kenta Uehara; and Mamoru Sekido
    Astrophys. J. Letter, 01 Jan. 2015, [Reviewed]
  • 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, [Reviewed]
  • VERA and ALMA observations of the H2O supermaser burst in Orion KL
    Tomoya Hirota; Masato Tsuboi; Yasutaka Kurono; Kenta Fujisawa; Mareki Honma; Mi Kyoung Kim; Hiroshi Imai; And Yoshinori Yonekura, The 22 GHz H2O maser in Orion KL has shown extraordinary burst events in 1979-1985 and 1998-1999, sometimes called supermaser. We have conducted monitoring observations of the supermaser in Orion KL using VERA (VLBI Exploration of Radio Astrometry) in the current third burst since 2011 March. Three flux maxima are detected in 2011 and 2012 with rising and falling timescales of 2-7 months. Time variations of the supermaser seem symmetric for all of the active phases. The maximum total flux density of 135000 Jy is observed in 2012 June while it is still one order of magnitude lower than those in previous bursts. The supermaser consists of two spatially different components at different velocities. They are elongated along a northwest-southeast direction perpendicular to the low-velocity outflow driven by Source I. Proper motions of the supermaser features with respect to Source I are measured toward west and southwest directions, almost parallel to the low-velocity outflow. The flux density and linewidth show an anti-correlation as expected for an unsaturated maser emission. The supermaser is located close to the methylformate (HCOOCH3) line and continuum emission peaks in the Orion Compact Ridge detected by ALMA (Atacama Large Millimeter/Submillimeter Array). The broader velocity range of the weak HCOOCH3 emission at the supermaser position would be evidence of a shock front. On the other hand, the 321 GHz H2O line is not detected at the position of the supermaser. It can be explained qualitatively by one of the theoretical H2O excitation models without extraordinary conditions. Our results support a scenario that the supermaser is excited in the dense gas interacting with the low-velocity outflow in the Compact Ridge. The extremely high flux density and its symmetric time variation for rising and falling phases could be explained by a beaming effect during the amplification process rather than changes in physical conditions., OXFORD UNIV PRESS
    Publ. Astron. Soc. Japan, 25 Dec. 2014, [Reviewed]
  • Observations of the bursting activity of the 6.7 GHz methanol maser in G33.641−0.228
    Kenta Fujisawa; Nozomu Aoki; Yoshito Nagadomi; Saki Kimura; Tadashi Shimomura; Genta Takase; Koichiro Sugiyama; Kazuhito Motogi; Kotaro Niinuma; Tomoya Hirota; And Yoshinori Yonekura, We have observed bursting variability of the 6.7 GHz methanol maser of G33.641-0.228. Five bursts were detected in the observation period of 294 days from 2009 to 2012. The typical burst is a large flux density rise in about one day followed by a slow fall. A non-typical burst observed in 2010 showed a large and rapid flux density enhancement from the stable state, but the rise and fall of the flux density were temporally symmetric and a fast fluctuation continued for 12 days. On average, the bursts occurred once every 59 days, although bursting was not periodic. Since the average power required for causing a burst of order of 10(21) Js(-1) is far smaller than the luminosity of G33.641-0.228, a very small fraction of the source's power would be sufficient to cause the burst occasionally. The burst can be explained as a solar-flare-like event in which the energy is accumulated in the magnetic field of the circumstellar disk, and is released for a short time. However, the mechanism of the energy release and the dust heating process are still unknown., OXFORD UNIV PRESS
    Publ. Astron. Soc. Japan, 25 Dec. 2014, [Reviewed]
  • Periodic Flare of the 6.7 GHz Methanol Maser in IRAS22198+6336
    Kenta Fujisawa; Genta Takase; Saki Kimura; Nozomu Aoki; Yoshito Nagadomi; Tadashi Shimomura; Koichiro Sugiyama; Kazuhito Motogi; Kotaro Niinuma; Tomoya Hirota; and Yoshinori Yonekura, We have detected periodic flares of the 6.7-GHz methanol maser from an intermediate-mass star-forming region IRAS 22198+6336. The maser was monitored daily in 2011, 2012, and 2013. Six flares were observed with a period of 34.6 d. The variation pattern is intermittent, and the flux ratio of the flaring and the quiescent states exceeds 30. Such intermittent variation with the short period uniquely characterizes the variation of the IRAS 22198+6336 maser. At least five spectral components were identified. The spectral components varied almost synchronously, but their peak times differed by 1.8 d. These characteristics can be explained by the colliding-wind binary model., OXFORD UNIV PRESS
    Publ. Astron. Soc. Japan, 25 Aug. 2014, [Reviewed]
  • Cluster Formation Triggered by Filament Collisions in Serpens South
    Fumitaka Nakamura; Koji Sugitani; Tomohiro Tanaka; Hiroyuki Nishitani; Kazuhito Dobashi; Tomomi Shimoikura; Yoshito Shimajiri; Ryohei Kawabe; Yoshinori Yonekura; Izumi Mizuno; Kimihiro Kimura; Kazuki Tokuda; Minato Kozu; Nozomi Okada; Yutaka Hasegawa; Hideo Ogawa; Tac Nakajima; Seiji Kameno; Hiroko Shinnaga; Munetake Momose; Hiroyuki Maezawa; Toshikazu Onishi; Tomoya HIROTA; Shuro Takano; Daisuke Iono; Nario Kuno; and Satoshi Yamamoto, 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
    Astrophys. J. Letter, 20 Aug. 2014, [Reviewed]
  • Periodic flare of the 6.7-GHz methanol maser in IRAS 22198+6336
    Fujisawa, Kenta; Takase, Genta; Kimura, Saki; Aoki, Nozomu; Nagadomi, Yoshito; Shimomura, Tadashi; Sugiyama, Koichiro; Motogi, Kazuhito; Niinuma, Kotaro; Hirota, Tomoya; Yonekura, Yoshinori
    Publications of the Astronomical Society of Japan, 01 Aug. 2014, [Reviewed]
  • Daily monitor of Sagittarius A* at 22 GHz with the Japanese VLBI Network
    M. Tsuboi; Y. Asaki; Y. Yonekura; Y. Miyamoto; H. Kaneko; M. Seta; N. Nakai; O. Kameya; M. Miyoshi; H. Takaba; K. Wakamatsu; Y. Fukuzaki; T. Morimitsu; K. Uehara; M. Sekido; T. Oka; S. Takekawa; T. Omodaka; T. Handa; A. Takumi, We have been monitoring the flux density of Sagittarius A* (Sgr A*) at 22 GHz since DOY=42 (11 Feb. 2013) with a sub-array of the Japanese VLBI Network in order to search the increase of 22-GHz emission from Sgr A* induced by the interaction of the G2 cloud with the accretion disk. The flux densities observed until DOY=322 (18 Nov. 2013) are consistent with the previously observed values before the approaching of the cloud. We have detected no large flare during this period. Copyright © International Astronomical Union 2014., Proceedings of the International Astronomical Union
    Proceedings of the International Astronomical Union, May 2014
  • Observations of 6.7 GHz Methanol Masers with EAVN I: VLBI Images of the first Epoch of Observations
    K. Fujisawa; K. Sugiyama; K. Motogi; K. Hachisuka; Y. Yonekura; S. Sawada-Satoh; N. Matsumoto; K. Sorai; M. Momose; Y. Saito; H. Takaba; H. Ogawa; K. Kimura; K. Niinuma; D. Hirano; T. Omodaka; H. Kobayashi; N. Kawaguchi; K. M. Shibata; M. Honma; T. Hirota; Y. Murata; A. Doi; N. Mochizuki; Z. Shen; X. Chen; B. Xia; B. Li; K.-T. Kim, Very-long-baseline interferometry (VLBI) monitoring of the 6.7 GHz 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., OXFORD UNIV PRESS
    Publ. Astron. Soc. Japan, 25 Apr. 2014, [Reviewed]
  • THE JET AND ARC MOLECULAR CLOUDS TOWARD WESTERLUND 2, RCW 49, AND HESS J1023-575; (CO)-C-12 AND (CO)-C-13 (J=2-1 and J=1-0) OBSERVATIONS WITH NANTEN2 AND MOPRA TELESCOPE
    N. Furukawa; A. Ohama; T. Fukuda; K. Torii; T. Hayakawa; H. Sano; T. Okuda; H. Yamamoto; N. Moribe; A. Mizuno; H. Maezawa; T. Onishi; A. Kawamura; N. Mizuno; J. R. Dawson; T. M. Dame; Y. Yonekura; F. Aharonian; E. de Ona Wilhelmi; G. P. Rowell; R. Matsumoto; Y. Asahina; Y. Fukui, We have made new CO observations of two molecular clouds, which we call "jet" and "arc" clouds, toward the stellar cluster Westerlund 2 and the TeV gamma-ray source HESS J1023-575. The jet cloud shows a linear structure from the position of Westerlund 2 on the east. In addition, we have found a new counter jet cloud on the west. The arc cloud shows a crescent shape in the west of HESS J1023-575. A sign of star formation is found at the edge of the jet cloud and gives a constraint on the age of the jet cloud to be similar to Myr. An analysis with the multi CO transitions gives temperature as high as 20 K in a few places of the jet cloud, suggesting that some additional heating may be operating locally. The new TeV gamma-ray images by H.E.S.S. correspond to the jet and arc clouds spatially better than the giant molecular clouds associated with Westerlund 2. We suggest that the jet and arc clouds are not physically linked with Westerlund 2 but are located at a greater distance around 7.5 kpc. A microquasar with long-term activity may be able to offer a possible engine to form the jet and arc clouds and to produce the TeV gamma-rays, although none of the known microquasars have a Myr age or steady TeV gamma-rays. Alternatively, an anisotropic supernova explosion which occurred similar to Myr ago may be able to form the jet and arc clouds, whereas the TeV gamma-ray emission requires a microquasar formed after the explosion., IOP PUBLISHING LTD
    ASTROPHYSICAL JOURNAL, Feb. 2014, [Reviewed]
  • Short-Term Radio Variability and Parsec-Scale Structure in a Gamma-Ray Narrow-Line Seyfert 1 Galaxy 1H 0323+342
    K. Wajima; K. Fujisawa; M. Hayashida; N. Isobe; T. Ishida; Y. Yonekura, We made simultaneous single-dish and very long baseline interferometer (VLBI) observations of a narrow-line Seyfert 1 galaxy 1H 323+342, showing gamma-ray activity revealed by Fermi/Large Area Telescope observations. We found significant variation of the total flux density at 8 GHz on the timescale of one month by the single-dish monitoring. The total flux density varied by 5.5% in 32 days, which is comparable to the gamma-ray variability timescale, corresponding to the variability brightness temperature of 7.0 x 10(11) K. The source consists of central and southeastern components on the parsec (pc) scale. Only the flux of the central component decreased in the same way as the total flux density, indicating that the short-term radio variability, and probably the gamma-ray-emitting region, is associated with this component. From the VLBI observations, we obtained brightness temperatures of greater than (5.2 +/- 0.3) x 10(10) K and derived an equipartition Doppler factor of greater than 1.7, a variability Doppler factor of 2.2, and an 8 GHz radio power of 10(24.6) W Hz(-1). Combining them, we conclude that acceleration of radio jets and creation of high-energy particles are ongoing in the central engine and that the apparent very radio-loud feature of the source is due to the Doppler boosting effect, resulting in the intrinsic radio loudness being an order of magnitude smaller than the observed values. We also conclude that the pc-scale jet represents recurrent activity from the spectral fitting and the estimated kinematic age of pc- and kpc-scale extended components with different position angles., IOP PUBLISHING LTD
    Astrophys. J., 01 Feb. 2014, [Reviewed]
  • The Jet and Arc Molecular Clouds Toward Westerlund 2, RCW 49, and HESS J1023-575; 12CO and 13CO (J=2-1 and J=1-0) Observations with NANTEN2 and Mopra
    N. Furukawa; A. Ohama; T. Fukuda; K. Torii; T. Hayakawa; H. Sano; T. Okuda; H. Yamamoto; N. Moribe; A. Mizuno; H. Maezawa; T. Onishi; A. Kawamura; N. Mizuno; J. R. Dawson; T. M. Dame; Y. Yonekura; F. Aharonian; E. de Oña Wilhelmi; G. P. Rowell; R. Matsumoto; Y. Asahina; and Y. Fukui, We have made new CO observations of two molecular clouds, which we call jet and arc clouds, toward the stellar cluster Westerlund 2 and the TeV γ-ray source HESS J1023-575. The jet cloud shows a linear structure from the position of Westerlund 2 on the east. In addition, we have found a new counter jet cloud on the west. The arc cloud shows a crescent shape in the west of HESS J1023-575. A sign of star formation is found at the edge of the jet cloud and gives a constraint on the age of the jet cloud to be Myr. An analysis with the multi CO transitions gives temperature as high as 20 K in a few places of the jet cloud, suggesting that some additional heating may be operating locally. The new TeV γ-ray images by H.E.S.S. correspond to the jet and arc clouds spatially better than the giant molecular clouds associated with Westerlund 2. We suggest that the jet and arc clouds are not physically linked with Westerlund 2 but are located at a greater distance around 7.5 kpc. A microquasar with long-term activity may be able to offer a possible engine to form the jet and arc clouds and to produce the TeV γ-rays, although none of the known microquasars have a Myr age or steady TeV γ-rays. Alternatively, an anisotropic supernova explosion which occurred Myr ago may be able to form the jet and arc clouds, whereas the TeV γ-ray emission requires a microquasar formed after the explosion. © 2014. The American Astronomical Society. All rights reserved., Institute of Physics Publishing
    Astrophys. J., 01 Feb. 2014, [Reviewed]
  • A 1.85-m mm-submm Telescope for Large-Scale Molecular Gas Surveys in (CO)-C-12, (CO)-C-13, and (CO)-O-18 (J=2-1)
    Onishi Toshikazu; Nishimura Atsushi; Ota Yuya; Hashizume Akio; Kojima Yoshiharu; Minami Akihito; Tokuda Kazuki; Touga Shiori; Abe Yasuhiro; Kaiden Masahiro; Kimura Kimihiro; Muraoka Kazuyuki; Maezawa Hiroyuki; Ogawa Hideo; Dobashi Kazuhito; Shimoikura Tomomi; Yonekura Yoshinori; Asayama Shin'ichiro; Handa Toshihiro; Nakajima Taku; Noguchi Takashi; Kuno Nario
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 25 Aug. 2013, [Reviewed]
  • A 1.85 m Mm-Submm Telescope for Large-Scale Molecular Gas Survey in 12CO, 13CO and C18O (J = 2 − 1)
    T. Onishi; A. Nishimura; Y. Ota; A. Hashizume; Y. Kojima; A. Minami; K. Tokuda; S. Touga; Y. Abe; M. Kaiden; K. Kimura; K. Muraoka; H. Maezawa; H. Ogawa; K. Dobashi; T. Shimoikura; Y. Yonekura; S. Asayama; T. Handa; T. Nakajima; T. Noguchi; And N. Kuno, We have developed a new mm-submm telescope with a diameter of 1.85-m installed at the Nobeyama Radio Observatory. The scientific goal is to precisely reveal the physical properties of molecular clouds in the Milky Way Galaxy by obtaining a large-scale distribution of molecular gas, which can also be compared with large-scale observations at various wavelengths. The target frequency is ̃230 GHz
    simultaneous observations at the molecular rotational lines of J = 2-1 of three carbon monoxide isotopes (12CO, 13CO, C18O) are achieved with a beam size (HPBW) of 2:07. In order to accomplish the simultaneous observations, we have developed waveguide-type sidebandseparating SIS mixers to obtain spectra separately in the upper and lower side bands. A Fourier digital spectrometer with a 1 GHz bandwidth having 16384 channels is installed, and the bandwidth of the spectrometer is divided into three parts, corresponding to each of the three spectra
    the IF system has been designed so as to inject these three lines into the spectrometer. A flexible observation system was created mainly in Python on Linux PCs, enabling effective OTF (On-The-Fly) scans for large-area mapping. The telescope is enclosed in a radome with a membrane covered to prevent any harmful effects of sunlight, strong wind, and precipitation in order to minimize errors in the telescope pointing, and to stabilize the receiver and the IF devices. From 2011 November, we started science operation, resulting in a large-scale survey of the Orion A/B clouds, Cygnus OB7, Galactic Plane, Taurus, and so on. We also updated the receiver system for dual-polarization observations. © 2013. Astronomical Society of Japan., Oxford University Press
    Publ. Astron. Soc. Japan, 25 Aug. 2013, [Reviewed]
  • Dense Optical and Near-infrared Monitoring of CTA 102 during High State in 2012 with OISTER: Detection of Intra-night "Orphan Polarized Flux Flare"
    R. Itoh; Y. Fukazawa; Y. T. Tanaka; Y. Abe; H. Akitaya; A. Arai; M. Hayashi; T. Hori; M. Isogai; H. Izumiura; K. S. Kawabata; N. Kawai; D. Kuroda; R. Miyanoshita; Y. Moritani; T. Morokuma; T. Nagayama; J. Nakamoto; C. Nakata; Y. Oasa; T. Ohshima; T. Ohsugi; S.-i. Okumura; Y. Saito; Y. Saito; M. Sasada; K. Sekiguchi; Y. Takagi; J. Takahashi; Y. Takahashi; K. Takaki; M. Uemura; I. Ueno; S. Urakawa; M. Watanabe; M. Yamanaka; Y. Yonekura; M. Yoshida, CTA 102, classified as a flat spectrum radio quasar at z = 1.037, produced an exceptionally bright optical flare in 2012 September. Following the Fermi Large Area Telescope detection of enhanced gamma-ray activity, we closely monitored this source in the optical and near-infrared bands for the 10 subsequent nights using 12 telescopes in Japan and South Africa. On MJD 56197 (2012 September 27, four to five days after the peak of bright gamma-ray flare), polarized flux showed a transient increase, while total flux and polarization angle (PA) remained almost constant during the "orphan polarized-flux flare." We also detected an intra-night and prominent flare on MJD 56202. The total and polarized fluxes showed quite similar temporal variations, but the PA again remained constant during the flare. Interestingly, the PAs during the two flares were significantly different from the jet direction. The emergence of a new emission component with a high polarization degree (PD) up to 40% would be responsible for the observed two flares, and such a high PD indicates the presence of a highly ordered magnetic field at the emission site. We argue that the well-ordered magnetic field and even the observed directions of the PA, which is grossly perpendicular to the jet, are reasonably accounted for by transverse shock(s) propagating down the jet., IOP PUBLISHING LTD
    Astrophys. J. Letter, May 2013, [Reviewed]
  • 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, [Reviewed]
  • The VLBI Imaging Survey of the 6.7 GHz Methanol Masers using the JVN/EAVN
    K. Sugiyama; K. Fujisawa; K. Hachisuka; Y. Yonekura; K. Motogi; M. Honma; T. Hirota; S. Sawada-Satoh; K. Niinuma; Y. Murata; A. Doi; H. Ogawa; Z. -Q. Shen, We present a result of the VLBI (very-long-baseline-interferometer) imaging survey for the 6.7 GHz methanol masers by using the Japanese VLBI Network (JVN) and the East-Asian VLBI Network (EAVN). We conducted VLBI observations for 36 methanol maser sources, and the spatial distribution of 35 sources were obtained, in which 33 sources provide new VLBI images. The spatial morphology was classified into five categories on the basis of the criteria used in the European VLBI Network observations (EVN: Bartkiewicz et al. 2009)., ASTRONOMICAL SOC PACIFIC
    NEW TRENDS IN RADIO ASTRONOMY IN THE ALMA ERA: THE 30TH ANNIVERSARY OF NOBEYAMA RADIO OBSERVATORY, 2013
  • High-Resolution Observations of Centimeter/(Sub)Millimeter H2O Masers in Orion KL with VERA and ALMA
    T. Hirota; M. Tsuboi; K. Fujisawa; M. Honma; N. Kawaguchi; M. K. Kim; H. Kobayashi; Y. Kurono; H. Imai; T. Omodaka; K. M. Shibata; T. Shimoikura; Y. Yonekura, We present the results of astrometry with VERA of the 22 GHz H2O maser burst in Orion KL started since 2011 February. According to the absolute positions and proper motions of the bursting H2O maser features, it is most likely that the outflow from the radio Source I or another young stellar object in the Compact Ridge is a possible origin of the burst. In addition, we report the first detection of the 232 GHz vibrationally excited H2O maser in star-forming regions by using the ALMA Science Verification data of Orion KL. The 232 GHz H2O maser is detected toward the Source I and its spectral profile shows a double-peaked structure analogous to the 22 GHz H2O and 43 GHz SiO masers. Thus, the 232 GHz H2O maser would be excited in the dense and hot gas around the Source I as in the case of other maser lines., ASTRONOMICAL SOC PACIFIC
    NEW TRENDS IN RADIO ASTRONOMY IN THE ALMA ERA: THE 30TH ANNIVERSARY OF NOBEYAMA RADIO OBSERVATORY, 2013, [Reviewed]
  • The VLBI mapping survey of the 6.7 GHz methanol masers with the JVN/EAVN
    K. Fujisawa; K. Hachisuka; K. Sugiyama; A. Doi; M. Honma; Y. Yonekura; T. Hirota; S. Sawada-Satoh; Y. Murata; K. Motogi; H. Ogawa; X. Chen; K. T. Kim; Z. Q. Shen, We present VLBI maps of the 6.7 GHz methanol maser emission in 32 sources obtained using the Japanese VLBI Network (JVN) and the East-Asian VLBI Network (EAVN). All of the observed sources provide new VLBI maps, and the spatial morphologies have been classified into five categories similar to the results obtained from European VLBI Network observations (Bartkiewicz et al. 2009). The 32 methanol sources are being monitored to measure the relative proper motions of the methanol maser spots. Copyright © International Astronomical Union 2012.
    Proceedings of the International Astronomical Union, Jul. 2012
  • VERA observations of the H2O maser burst in orion KL
    Tomoya Hirota; Masato Tsuboi; Kenta Fujisawa; Mareki Honma; Noriyuki Kawaguchi; Mi Kyoung Kim; Hideyuki Kobayashi; Hiroshi Imai; Toshihiro Omodaka; Katsunori M. Shibata; Tomomi Shimoikura; Yoshinori Yonekura, In 2011 February, a burst of the 22 GHz H2O maser in Orion KL was reported. In order to identify the bursting maser features, we have been carrying out observations of the 22 GHz H2O maser in Orion KL with VERA, a Japanese VLBI network dedicated for astrometry. The bursting maser turns out to consist of two spatially different features at 7.58 and 6.95 km s-1. We determine their absolute positions and find that they are coincident with the shocked molecular gas called the Orion Compact Ridge. We tentatively detect the absolute proper motions of the bursting features toward the southwest direction, perpendicular to the elongation of the maser features. It is most likely that the outflow from the radio source I or another young stellar object interacting with Compact Ridge is a possible origin of the H2O maser burst. We will also carry out observations with ALMA in the cycle 0 period to monitor the submillimeter H2O maser lines in the Orion Compact Ridge region. These follow-up observations will provide novel information on the physical and chemical properties of the mastering region. Copyright © International Astronomical Union 2012.
    Proceedings of the International Astronomical Union, Jul. 2012, [Reviewed]
  • Bursting Activity in a High-Mass Star-Forming Region G33.64-0.21 Observed with the 6.7 GHz Methanol Maser
    Kenta Fujisawa; Koichiro Sugiyama; Nozomu Aoki; Tomoya Hirota; Nanako Mochizuki; Akihiro Doi; Mareki Honma; Hideyuki Kobayashi; Noriyuki Kawaguchi; Hideo Ogawa; Toshihiro Omodaka; Yoshinori Yonekura, We report on the detection of bursts of 6.7 GHz methanol maser emission in a high-mass star-forming region, G33.64-0.21. One of the spectral components of the maser in this source changed its flux density by 7 times that of the previous day, and it decayed with a timescale of 5 days. The burst occurred repeatedly in the spectral component, and no other components showed such variability. A VLBI observation with the Japanese VLBI Network (JVN) showed that the burst location was at the southwest edge of a spatial distribution, and the bursting phenomenon occurred in a region much smaller than 70 AU. We suggest an impulsive energy release, like a stellar flare, as a possible mechanism for the burst. These results imply that 6.7 GHz methanol masers could be a useful new probe for studying bursting activity in the process of the star formation of high-mass YSOs with a high-resolution of AU scale., OXFORD UNIV PRESS
    Publ. Astron. Soc. Japan, 25 Feb. 2012, [Reviewed]
  • Identification of Bursting Water Maser Features in Orion KL               
    Tomoya Hirota; Masato Tsuboi; Kenta Fujisawa; Mareki Honma; Noriyuki Kawaguchi; Mi Kyoung Kim; Hideyuki Kobayashi; Hiroshi Imai; Toshihiro Omodaka; Katsunori; M. Shibata; Tomomi Shimoikura; Yoshinori Yonekura
    Astrophys. J. Letter, 01 Oct. 2011, [Reviewed]
  • The Galactic Census of High- and Medium-Mass Protostars. I. Catalogs and First Results from Mopra HCO+ Maps
    Peter J. Barnes; Yoshinori Yonekura; Yasuo Fukui; Andrew T. Miller; Martin Mühlegger; Lawrence C. Agars; Yosuke Miyamoto; Naoko Furukawa; George Papadopoulos; Scott L. Jones; Audra K. Hernandez; Stefan N. O'Dougherty and Jonathan C. Tan, The Census of High- and Medium-mass Protostars (CHaMP) is the first large-scale, unbiased, uniform mapping survey at sub-parsec-scale resolution of 90 GHz line emission from massive molecular clumps in the Milky Way. We present the first Mopra (ATNF) maps of the CHaMP survey region (300 degrees > l > 280 degrees) in the HCO+ J = 1 -> 0 line, which is usually thought to trace gas at densities up to 10(11) m(-3). In this paper, we introduce the survey and its strategy, describe the observational and data reduction procedures, and give a complete catalog of moment maps of the HCO+ J = 1 -> 0 emission from the ensemble of 303 massive molecular clumps. From these maps we also derive the physical parameters of the clumps, using standard molecular spectral-line analysis techniques. This analysis yields the following range of properties: integrated line intensity 1-30 K km s(-1), peak line brightness 1-7 K, linewidth 1-10 km s(-1), integrated line luminosity 0.5-200 K km s(-1) pc(2), FWHM size 0.2-2.5 pc, mean projected axial ratio 2, optical depth 0.08-2, total surface density 30-3000 M-circle dot pc(-2), number density (0.2-30) x 10(9) m(-3), mass 15-8000 M-circle dot, virial parameter 1-55, and total gas pressure 0.3-700 pPa. We find that the CHaMP clumps do not obey a Larson-type size-linewidth relation. Among the clumps, there exists a large population of subthermally excited, weakly emitting (but easily detectable) dense molecular clumps, confirming the prediction of Narayanan et al. These weakly emitting clumps comprise 95% of all massive clumps by number, and 87% of the molecular mass, in this portion of the Galaxy; their properties are distinct from the brighter massive star-forming regions that are more typically studied. If the clumps evolve by slow contraction, the 95% of fainter clumps may represent a long-lived stage of pressure-confined, gravitationally stable massive clump evolution, while the CHaMP clump population may not engage in vigorous massive star formation until the last 5% of their lifetimes. The brighter sources are smaller, denser, more highly pressurized, and closer to gravitational instability than the less bright sources. Our data suggest that massive clumps approach critical Bonnor-Ebert-like states at constant density, while others' suggest that lower-mass clumps reach such states at constant pressure. Evidence of global gravitational collapse of massive clumps is rare, suggesting that this phase lasts <1% of the clumps' lifetime., IOP PUBLISHING LTD
    Astrophys. J. Suppl. Series, Sep. 2011, [Reviewed]
  • A Pan-Carina YSO Catalog: Intermediate-Mass Young Stellar Objects in the Carina Nebula Identified via Mid-Infrared Excess Emission
    Matthew S. Povich 他14名 (第14著者), We present a catalog of 1439 young stellar objects (YSOs) spanning the 1.42 deg(2) field surveyed by the Chandra Carina Complex Project (CCCP), which includes the major ionizing clusters and the most active sites of ongoing star formation within the Great Nebula in Carina. Candidate YSOs were identified via infrared (IR) excess emission from dusty circumstellar disks and envelopes, using data from the Spitzer Space Telescope (the Vela-Carina survey) and the Two-Micron All Sky Survey. We model the 1-24 mu m IR spectral energy distributions of the YSOs to constrain physical properties. Our Pan-Carina YSO Catalog (PCYC) is dominated by intermediate-mass (2 M-circle dot < m less than or similar to 10 M-circle dot) objects with disks, including Herbig Ae/Be stars and their less evolved progenitors. The PCYC provides a valuable complementary data set to the CCCP X-ray source catalogs, identifying 1029 YSOs in Carina with no X-ray detection. We also catalog 410 YSOs with X-ray counterparts, including 62 candidate protostars. Candidate protostars with X-ray detections tend to be more evolved than those without. In most cases, X-ray emission apparently originating from intermediate-mass, disk-dominated YSOs is consistent with the presence of low-mass companions, but we also find that X-ray emission correlates with cooler stellar photospheres and higher disk masses. We suggest that intermediate-mass YSOs produce X-rays during their early pre-main-sequence evolution, perhaps driven by magnetic dynamo activity during the convective atmosphere phase, but this emission dies off as the stars approach the main sequence. Extrapolating over the stellar initial mass function scaled to the PCYC population, we predict a total population of > 2 x 10(4) YSOs and a present-day star formation rate (SFR) of >0.008 M-circle dot yr(-1). The global SFR in the Carina Nebula, averaged over the past similar to 5 Myr, has been approximately constant., IOP PUBLISHING LTD
    Astrophys. J. Suppl. Series, May 2011, [Reviewed]
  • Source Contamination in X-ray Studies of Star-Forming Regions: Application to the Chandra Carina Complex Project
    Konstantin V.Getman 他8名 (第8著者), We describe detailed simulations of X-ray-emitting populations to evaluate the levels of contamination by both Galactic and extragalactic X-ray sources unrelated to a star-forming region under study. For Galactic contaminations, we consider contribution from main-sequence stars and giants (not including cataclysmic variables and other classes of accretion-driven X-ray binary systems), as they make the dominant contribution at the position of the Carina Nebula. The simulations take into consideration a variety of technical factors involving a Galactic population synthesis model, stellar X-ray luminosity functions, Chandra telescope response, source detection methodology, and possible spatial variations in the X-ray background and absorption through molecular clouds. When applied to the 1.42 deg(2) field of the Chandra Carina Complex Project (CCCP), the simulations predict similar to 5000 contaminating sources (1 source arcmin(-2) of the survey), evenly distributed across the field. The results of the simulations are further employed in a companion CCCP study to assign membership probabilities to individual sources., IOP PUBLISHING LTD
    Astrophys. J. Suppl. Series, May 2011, [Reviewed]
  • Photon Dominated Regions in NGC 3603
    M. Röllig; C. Kramer; C. Rajbahak; T. Minamidani; K. Sun; R. Simon; V. Ossenkopf; M. Cubick; M. Hitschfeld; M. Aravena; F. Bensch; F. Bertoldi; L. Bronfman; M. Fujishita; Y. Fukui; U.U. Graf; N. Honingh; S. Ito; H. Jakob; K. Jacobs; U. Klein; B.-C. Koo; J. May; M. Miller; Y. Miyamoto; N. Mizuno; T. Onishi; Y.-S. Park; J. Pineda; D. Rabanus; H. Sasago; R. Schieder; J. Stutzki; H. Yamamoto; Y. Yonekura, Aims. We aim at deriving the excitation conditions of the interstellar gas as well as the local FUV intensities in the molecular cloud surrounding NGC 3603 to get a coherent picture of how the gas is energized by the central stars.
    Methods. The NANTEN2-4 m submillimeter antenna is used to map the [CI] 1-0, 2-1 and CO 4-3, 7-6 lines in a 2' x 2' region around the young OB cluster NGC 3603 YC. These data are combined with (CO)-O-18 2-1 data, HIRES-processed IRAS 60 mu m and 100 mu m maps of the FIR continuum, and Spitzer/IRAC maps.
    Results. The NANTEN2 observations show the presence of two molecular clumps located south-east and south-west of the cluster and confirm the overall structure already found by previous CS and (CO)-O-18 observations. We find a slight position offset of the peak intensity of CO and [CI], and the atomic carbon appears to be further extended compared to the molecular material. We used the HIRES far-infrared dust data to derive a map of the FUV field heating the dust. We constrain the FUV field to values of chi = 3-6 x 10(3) in units of the Draine field across the clouds. Approximately 0.2 to 0.3% of the total FUV energy is re-emitted in the [CII] 158 mu m cooling line observed by ISO. Applying LTE and escape probability calculations, we derive temperatures (T-MM1 = 43 K, T-MM2 = 47 K), column densities (N-MM1 = 0.9 x 10(22) cm(-2), N-MM2 = 2.5 x 10(22) cm(-2)) and densities (n(MM1) = 3 x 10(3) cm(-3), n(MM2) = 10(3) - 10(4) cm(-3)) for the two observed molecular clumps MM1 and MM2.
    Conclusions. The cluster is strongly interacting with the ambient molecular cloud, governing its structure and physical conditions. A stability analysis shows the existence of gravitationally collapsing gas clumps which should lead to star formation. Embedded IR sources have already been observed in the outskirts of the molecular cloud and seem to support our conclusions., EDP SCIENCES S A
    Astron. Astrophys., Jan. 2011, [Reviewed]
  • The AMANOGAWA-2SB Galactic Plane Survey. I: The Data on the Galactic Equator
    Takahiro Yoda; Toshihiro Handa; Kotaro Kohno; Taku Nakajima; Masahiro Kaiden; Yoshinori Yonekura; Hideo Ogawa; Jun-ichi Morino; and Kazuhito Dobashi, Using a waveguide-type sideband-separating receiver (2SB receiver) on the Tokyo-NRO 60-cm telescope (renamed the AMANOGAWA telescope), we carried out simultaneous observations in the (CO)-C-12 (J = 2-1) and (CO)-C-13 (J = 2-1) lines over the galactic plane l = 10 degrees-245 degrees along b = 0 degrees with a 3.'75 grid. Using the (CO)-C-12 (J = 1-0) data of Dame et al. (2001, ApJ, 547,792), who used a beam size almost the same as ours, we show (CO)-C-12 (J = 2-1)/(CO)-C-12 (J = 1-0) and (CO)-C-13 (J = 2-1)/(CO)-C-12 (J = 2-1) intensity ratios on the l-v map and the intensity correlations among the (CO)-C-12 (J = 2-1), (CO)-C-13 (J = 2-1), and (CO)-C-12 (J = 1-0) lines. As a result, a linear correlation between (CO)-C-12 (J = 2-1) and (CO)-C-12 (J = 1-0) and a curved correlation between (CO)-C-12 (J = 2-1) and (CO)-C-13 (J = 2-1), as produced by most of the data, have been found. We investigated these correlations with simple radiative transfer equations to ascertain a number of restrictions on the physical quantities of molecular gas on a galactic scale., OXFORD UNIV PRESS
    Publ. Astron. Soc. Japan, 25 Oct. 2010, [Reviewed]
  • The Radio-FIR correlation in the Milky Way
    Zhang; J.; Hopkins; A.; Barnes; P.J.; Cagnes; M.; Yonekura; Y.; Fukui; Y., We investigate the scale on which the correlation arises between the 843 MHz radio and the 60 mm far-infrared (FIR) emission from star forming regions in the Milky way. The correlation, which exists on the smallest scales investigated (down to approximate to 4 pc), becomes noticeably tight on fields of size 300, corresponding to physical scales of approximate to 20-50 pc. The FIR to radio flux ratio on this scale is consistent with the radio emission being dominated by thermal emission. We also investigate the location dependence of q(mean), a parameter measuring the mean FIR to radio flux ratio, of a sample of star forming regions. We show that qmean displays a modest dependence on galactic latitude. If this is interpreted as a dependence on the intensity of star formation activity, the result is consistent with studies of the Large Magellanic Cloud (LMC) and other nearby galaxies that show elevated values for q in regions of enhanced star formation., CSIRO PUBLISHING
    Publications of the Astronomical Society of Australia, Sep. 2010, [Reviewed]
  • Discovery of large-scale gravitational infall in a massive protostellar cluster
    Peter J. Barnes; Yoshinori Yonekura; Stuart D. Ryder; Andrew M. Hopkins; Yosuke Miyamoto; Naoko Furukawa; and Yasuo Fukui, We report Mopra Australia Telescope National Facility (ATNF), Anglo-Australian Telescope and Atacama Submillimeter Telescope Experiment observations of a molecular clump in Carina, BYF73 = G286.21+0.17, which give evidence of large-scale gravitational infall in the dense gas. From the millimetre and far-infrared data, the clump has a mass of similar to 2 x 104 M-circle dot, luminosity of similar to 2-3 x 104 L-circle dot and diameter of similar to 0.9 pc. From radiative transfer modelling, we derive a mass infall rate of similar to 3.4 x 10-2 M-circle dot yr-1. If confirmed, this rate for gravitational infall in a molecular core or clump may be the highest yet seen. The near-infrared K-band imaging shows an adjacent compact H ii region and IR cluster surrounded by a shell-like photodissociation region showing H-2 emission. At the molecular infall peak, the K imaging also reveals a deeply embedded group of stars with associated H-2 emission. The combination of these features is very unusual, and we suggest that they indicate the ongoing formation of a massive star cluster. We discuss the implications of these data for competing theories of massive star formation., OXFORD UNIV PRESS
    Monthly Notices of the Royal Astronomical Society, Feb. 2010, [Reviewed]
  • Simulation of the Optical System for the ASTRO-G Offset Cassegrain Antenna
    K. Kimura; T. Toshikawa; N. Shiroyama; A. Kurozumi; T. K. Ojima; Y. Abe; Y. Yonekura; H. Ogawa; H. Ujihara; Y. Murata; M. Tsuboi; T. Kasuga, We are developing the satellite (ASTRO-G) for the space VLBI mission, called VSOP-2 (Hirabayashi et al. 2004). This system will have an offset cassegrain antenna, and the three multi-mode feed horns (8, 22, 43 GHz bands) will be chosen by the Cassegrain focus position. We are designing the antenna optics of the three band receivers by using the GRASP physical optics software package on simulated feed configurations. The result of these simulations shows low cross-polarization level, a good radiation pattern, and the antenna efficiencies are 63-68 percent in these bands, assuming a perfect reflector. In this paper, we present these results of simulation of ASTRO-G antenna optics., ASTRONOMICAL SOC PACIFIC
    APPROACHING MICRO-ARCSECOND RESOLUTION WITH VSOP-2: ASTROPHYSICS AND TECHNOLOGY, 2009, [Reviewed]
  • High-Resolution Studies of the Multiple-Core Systems toward Cluster-Forming Regions including Massive Stars
    Hiro Saito; Masao Saito; Yoshinori Yonekura; and Fumitaka Nakamura, We present the results of C(18)O observations by the Nobeyama Millimeter Array toward dense clumps with radii of similar to 0.3 pc in six cluster-forming regions including massive (proto) stars. We identified 171 cores, whose radius, line width, and molecular mass range from 0.01 to 0.09 pc, 0.43 to 3.33 km s(-1), and 0.5 to 54.1 M(circle dot), respectively. Many cores with various line widths exist in one clump, and the index of the line width-radius relationship of the cores and the parental clump differs from core to core in the clump. This indicates that the degree of dissipation of the turbulent motion varies for each core in one clump. Although the mass of the cores increases with the line width, most cores are gravitationally bound by the external pressure. In addition, the linewidth and the external pressure of the cores tend to decrease with the distance from the center of the clump, and these dependencies may be caused by the inner H(2) density structure of the clump that affects the physical properties of the cores. Moreover, the number density of the cores and the number density of young (proto) stars have a similar relationship to the average H(2) density of the clumps. Thus, our findings suggest that the cluster is formed in the clump through the formation of such multiple cores, whose physical properties would have been strongly related to the H(2) density structure and the turbulent motion of the clump., IOP PUBLISHING LTD
    Astrophys. J. Suppl. Series, Oct. 2008, [Reviewed]
  • THE SECOND SURVEY OF THE MOLECULAR CLOUDS IN THE LARGE MAGELLANIC CLOUD BY NANTEN. I. CATALOG OF MOLECULAR CLOUDS
    Y. Fukui; A. Kawamura; T. Minamidani; Y. Mizuno; Y. Kanai; N. Mizuno; T. Onishi; Y. Yonekura; A. Mizuno; H. Ogawa; M. Rubio, The second survey of the molecular clouds in the Large Magellanic Cloud in (CO)-C-12 (J = 1-0) was carried out by NANTEN. The sensitivity of this survey is twice as high as that of the previous NANTEN survey, leading to a detection of molecular clouds with M-CO greater than or similar to 2 x 10(4) M-circle dot. We identified 272 molecular clouds, 230 of which are detected at three or more observed positions. We derived the physical properties, such as size, line width, and virial mass, of the 164 GMCs that have an extent more than the beam size of NANTEN in both the major and minor axes. The CO luminosity and virial mass of the clouds show a good correlation of M-vir proportional to L-CO(1.1 +/- 0.1), with a Spearman rank correlation of 0.8, suggesting that the clouds are in nearly virial equilibrium. Assuming the clouds are in virial equilibrium, we derived an X-CO-factor of similar to 7 x 10(20) cm(-2) (K km s(-1))(-1). The mass spectrum of the clouds is fitted well by a power law of N-cloud(> M-CO) proportional to M-CO(-0.75 +/- 0.06) above the completeness limit of 5 x 10(4) M-circle dot. The slope of the mass spectrum becomes steeper if we fit only the massive clouds, e. g., N-cloud(> M-CO) proportional to M-CO(-1.2 +/- 0.2) for M-CO >= 3 x 10(5) M-circle dot., IOP PUBLISHING LTD
    ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, Sep. 2008, [Reviewed]
  • A new 100-GHz band front-end system with a waveguide-type dual-polarization sideband-separating SIS receiver for the NRO 45-m radio telescope
    Taku Nakajima; Takeshi Sakai; Shin'ichiro Asayama; Kimihiro Kimura; Masayuki Kawamura; Yoshinori Yonekura; Hideo Ogawa; Nario Kuno; Takashi Noguchi; Masato Tsuboi; Ryohei Kawabe, We developed a waveguide-type dual-polarization sideband-separating SIS receiver system of the 100-GHz band for the 45-m radio telescope at the Nobeyama Radio Observatory, Japan. This receiver is composed of an orthomode transducer and two sideband-separating SIS mixers, which are both based on a waveguide technique. The receiver has four intermediate frequency (IF) bands of 4.0-8.0 GHz. Over the radio frequency range of 80-120 GHz, the single-sideband receiver noise temperatures are 50-100 K, and the image rejection ratios (IRRs) are greater than 10 dB. We developed new matching optics for the telescope beam as well as new IF chains for the four IF signals. The new receiver system was installed in the telescope, and we successfully observed the 12CO, 13CO, and C18O emission lines simultaneously toward the Sagittarius B2 region to confirm the performance of the receiver system. The SSB noise temperature of the system, including the atmosphere, became approximately half of that of the previous receiver system. The IRRs of the two 2SB mixers were estimated from the 12CO and HCO+ spectra from the W 51 giant molecular cloud, resulting in > 20 dB for one polarization and > 12 dB for the other polarization. © 2008. Astronomical Society of Japan.
    Publications of the Astronomical Society of Japan, 2008, [Reviewed]
  • A New 60-cm Radio Survey Telescope with the Sideband-Separating SIS Receiver for the 200 GHz Band               
    Taku Nakajima; Masahiro Kaiden; Jun Korogi; Kimihiro Kimura; Yoshinori Yonekura; Hideo Ogawa; Shingo Nishiura; Kazuhito Dobashi; Toshihiro Handa; Kotaro Kohno; Jun-Ichi Morino; Shin'ichiro Asayama; Takashi Noguchi
    Publ. Astron. Soc. Japan, Oct. 2007, [Reviewed]
  • Molecular Loops in the Galactic Center: Evidence for Magnetic Flotation               
    Y. Fukui; H. Yamamoto; M. Fujishita; N. Kudo; K. Torii; S. Nozawa; K. Takahashi; R. Matsumoto; M. Machida; A. Kawamura; Y. Yonekura; N. Mizuno; T. Onishi; A. Mizuno, 銀河系中心部で特異なループ構造を持つ分子雲ループを観測した。その結果、従来の超新星爆発とは異なる構造を明らかにした。それはは太陽表面で見られる「パーカー不安定」による現象を銀河系中心部に応用するものであり、サイズとしては太陽表面のループ現象より12桁ほど巨大なものであった。そこで、その構造を理論的に解明するために、銀河ループ構造のモデルの検証として二次元電磁流体シミュレーションを用い、そのモデルが正しいことを提唱した(担当:計算、解析、結果分析)
    Science, 2006, [Reviewed]
  • A CO survey of the LMC with NANTEN: II. Catalog of molecular clouds
    N Mizuno; R Yamaguchi; A Mizuno; M Rubio; R Abe; H Saito; T Onishi; Y Yonekura; N Yamaguchi; H Ogawa; Y Fukui, From a (CO)-C-12 (J = 1-0) survey with the NANTEN telescope, we present a complete catalog of giant molecular clouds (GMCs) in the Large Magellanic Cloud. In total, 107 CO clouds have been identified, 55 of which were detected at more than 3 observed positions. For the 55 clouds, the physical properties, such as size, line-width, virial mass, and CO luminosity, are cataloged. From a statistical analysis of these quantities, we show that GMCs in the LMC are close to gravitational equilibrium. A comparison with Hi data indicates that most of the CO clouds are distributed in dense parts of 14 1 gas, whose H I column density is greater than 10(21) cm(-2). It is notable that the mass ratio of the molecular-to-atomic hydrogen of the lower radial velocity component of gas is similar to 0.2, which is a factor of 2 higher than Chat of the gaseous-disk component, similar to 0.1. Molecular clouds are apparently formed efficiently in the parent atomic clouds in the lower velocity component. The CO Arc, which is a few kpc scale ordered structure of CO clouds along the southern optical edge of the galaxy, corresponds well to the the lower velocity component of HI gas., OXFORD UNIV PRESS
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Dec. 2001, [Reviewed]
  • A CO Survey of the LMC with NANTEN; III. Formation of Stellar Clusters and Evolution of Molecular Clouds
    R. Yamaguchi; N. Mizuno; A. Mizuno; M. Rubio; R. Abe; H. Saito; Y. Moriguchi; K. Matsunaga; T. Onishi; Y. Yonekura; Y. Fukui
    Publ. of the Astron. Soc. Japan, Dec. 2001, [Reviewed]
  • Statistical study of dense cores in nearby star forming regions
    K Tachihara; A Hara; T Onishi; A Mizuno; Y Fukui; A Obayashi; Y Yonekura, We have carried out dense core surveys in (CO)-O-18 (J = 1-0) with NANTEN and the 4m radio telescopes in Nagoya University. In total 160 dense cores have been catalogued in nearby star forming regions, i.e., Taurus, L1333, Ophiuchus, Lupus, Corona Australis, and Chamaeleon (Onishi et al. 1996; Obayashi et al. 1998; Tachihara et al. 2000; Hara et al. 1999; Yonekura et al. 1999; Mizuno et al. 1999). This is one of the largest samples of the dense cores ever taken. We made a statistical study of star and cluster formation with the cores. The physical parameters of M, R, DeltaV, N(H-2), and n(H-2) of the (CO)-O-18 cores range 1.1-540 Mcircle dot, 0.07-0.45 pc, 0.32-1.94 km s(-1), (2.4-72) x 10(21) cm(-2), and (1.9-51) x 10(3) cm(-3), respectively. The total mass spectrum of the (CO)-O-18 cores is obtained, and we found that it is hardly expressed as a single power-law function and there seems to be turnover around M similar to 10Mcircle dot. In order to characterize the properties of the cares in terms of star forming activity, we categorized the cores into 3 groups as starless, star-forming, and cluster-forming cores according to the number of associated YSOs, and compared the physical parameters among them. Star-forming cores tend to be larger than starless cores in all the physical parameters except for DeltaV, and the cluster-forming cores are significantly larger than the others in all these parameters except for R. The virial analysis shaves that the star-forming cores have smaller virial ratios, M-Vir/M, i.e., more gravitationally bound, while the starless cores are not. The cluster-forming cores have moderate virial ratios. These facts imply that star-formation requires turbulence in the cores to be dissipated, and the formed clusters may enhance the turbulence. It seems that some of the cluster-forming cores will be dissipated in the near future., ASTRONOMICAL SOC PACIFIC
    FROM DARKNESS TO LIGHT: ORIGIN AND EVOLUTION OF YOUNG STELLAR CLUSTERS, 2001, [Reviewed]
  • First results of a CO survey of the Large Magellanic Cloud with NANTEN; Giant molecular clouds as formation sites of populous clusters
    Y Fukui; N Mizuno; R Yamaguchi; A Mizuno; T Onishi; H Ogawa; Y Yonekura; A Kawamura; K Tachihara; KC Xiao; N Yamaguchi; A Hara; T Hayakawa; S Kato; R Abe; H Saito; S Mano; K Matsunaga; Y Mine; Y Moriguchi; H Aoyama; S Asayama; N Yoshikawa; M Rubio, A new survey of the LMC has been completed in 2.6 mm carbon monoxide emission with NANTEN. This survey has revealed 107 giant molecular clouds, the first complete sample of giant molecular clouds in a single galaxy at a linear resolution of similar to 40 pc. The cloud mass ranges from similar to 6 x 10(4) to 2 x 10(6) M., and the total molecular mass has been estimated to be 4-7 x 10(7) M. for a molecular column density of greater than or similar to 1.0 x 10(21) cm(-2), corresponding to 5-10% of the atomic mass. The molecular clouds exhibit a good spatial correlation with the youngest stellar clusters whose ages are less than or similar to 10 Myr, demonstrating that cluster formation is on-going in these clouds. On the other hand, they show little correlation with older clusters or with supernova remnants, suggesting that the molecular clouds are being rapidly dissipated in several Myrs, probably due to the UV photons of massive stars in clusters., OXFORD UNIV PRESS
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Dec. 1999, [Reviewed]
  • A new derivation of the extinction-to-CO column density ratio in the Chamaeleon I dark cloud
    T Hayakawa; A Mizuno; T Onishi; Y Yonekura; A Hara; R Yamaguchi; Y Fukui, We have analyzed new datasets of (CO)-C-13 (J = 1-0)and (CO)-O-18 (J = 1-0) emission obtained with NANTEN and visual extinction, Av, derived from DENIS J-band observations in the Chamaeleon I dark cloud. The column densities of both molecular isotopes, N((CO)-C-13) and N((CO)-O-18), have been derived assuming LTE. Both N((CO)-C-13) and IV((CO)-O-18) are linearly correlated with Av in the range Av less than or similar to 10 mag. WE established the relationships N((CO)-C-13)(cm(-2)) = (1.2 +/- 0.1) x 10(15)Av(mag) + (0.7 +/- 0.3) x 10(15) and N((CO)-O-18)(cm(-2)) = (3.5 +/- 0.3) x 10(14)Av(mag) - (5.7 +/- 13) x 10(14). In a region of clustered T Tauri stars, however, both the AV-N(13CO) and Av-N((CO)-O-18) relationships are by a factor of similar to 2 steeper than the above. This may be mainly due to underestimates of the A(V) values, and the J-band star count might deserve a more careful examination for possible underestimates of associated young stars. Compared with the relationships for the other clouds, the slope of the A(V)-N((CO)-C-13) relationship is relatively shallower and that of the A(V)-N((CO)-O-18) relationship in a non-cluster forming region is slightly steeper. These facts suggest that cloud-to-cloud variation is significant in the A(V)-N(CO) relationships., OXFORD UNIV PRESS
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Dec. 1999, [Reviewed]
  • Search for Molecular Clouds toward Intermediate-to-High Latitude IRAS Sources in the Southern Sky
    Y. Yonekura; T. Hayakawa; N. Mizuno; Y. Mine; A. Mizuno; H. Ogawa; Y. Fukui
    Publ. of the Astron. Soc. Japan, Dec. 1999, [Reviewed]
  • Distribution and Kinematics of the Molecular Clouds in the Gum Nebula
    N. Yamaguchi; N. Mizuno; Y. Moriguchi; Y. Yonekura; A. Mizuno; Y. Fukui
    Publ. of the Astron. Soc. Japan, Dec. 1999, [Reviewed]
  • NANTEN Observations of Dense Cores in the Corona Australis Molecular Cloud
    Y. Yonekura; N. Mizuno; H. Saito; A. Mizuno; H. Ogawa; Y. Fukui
    Publ. of the Astron. Soc. Japan, Dec. 1999, [Reviewed]
  • Molecular clouds in the LMC observed with NANTEN II. Comparison with stellar clusters
    R Yamaguchi; R Abe; A Hara; T Hayakawa; S Kato; A Kawamura; A Mizuno; N Mizuno; H Ogawa; T Onishi; H Saito; K Tachihara; KC Xiao; N Yamaguchi; Y Fukui; Y Yonekura, We have made (CO)-C-12(J=1-0) observations of the LMC with the NANTEN millimeter-wave telescope and identified about 100 distinct giant molecular clouds (GMCs). A detailed comparison of the GMCs with stellar clusters and a UV image is discussed., ASTRONOMICAL SOC PACIFIC
    NEW VIEWS OF THE MAGELLANIC CLOUDS, 1999, [Reviewed]
  • Molecular clouds in the LMC observed with NANTEN I. Physical properties of the clouds
    N Mizuno; R Abe; A Hara; T Hayakawa; S Kato; A Kawamura; A Mizuno; H Ogawa; T Onishi; H Saito; K Tachihara; KC Xiao; N Yamaguchi; R Yamaguchi; Y Fukui; Y Yonekura, Fully sampled (CO)-C-12(J=1-0) observations of the whole extent of the LMC have been made with a linear resolution of similar to 30 pc at a detection limit of N(H-2) = 2 x 10(21) cm(-2). In addition, several selected regions have been mapped with higher sensitivity corresponding to a detection limit of 1 x 10(21) cm(-2). Based on these results, a new estimate of the molecular mass in the LMC is presented., ASTRONOMICAL SOC PACIFIC
    NEW VIEWS OF THE MAGELLANIC CLOUDS, 1999, [Reviewed]
  • Interaction between a massive molecular outflow and dense gas associated with IRAS 22142+5206
    K Dobashi; Y Yonekura; Y Hayashi; F Sato; H Ogawa, We report results of (CO)-C-12, (CO)-C-13, and (CO)-O-18 (J = 1-0) observations made toward the luminous protostellar candidate IRAS 22142 + 5206 (similar to 16,100 L., at its kinematic distance of 4.5 kpc) using the 45 m telescope at Nobeyama Radio Observatory. We have discovered a massive CO outflow with a molecular mass of similar to 33 M., which is among the more massive outflows reported to date. The outflow lobes extend to over similar to 2 pc from the IRAS source. Dense gas (similar to 1140 M.) with an elliptical shape is also found around the source, with a velocity gradient of similar to 0.5 km s(-1) pc(-1) along its major axis. We find a cavity in the dense gas at positions where the CO outflow is prominent. We discuss the origin of the cavity, estimating the mechanical momentum and kinetic energy of the outflow, and conclude that the cavity was most likely created by the high-velocity jet of the outflow, which may have swept up part of the dense gas. We also carried out extensive (CO)-C-13 observations toward the IRAS source using the Nagoya 4 m telescope in order to reveal the overall distribution of molecular gas around the source. The results of these observations indicate that the IRAS source is embedded in a molecular cloud with a mass of 7300 M.., IOP PUBLISHING LTD
    ASTRONOMICAL JOURNAL, Feb. 1998, [Reviewed]
  • Relations between star formation and the interstellar medium
    Y Fukui; Y Yonekura, We review observational results concerning star formation and dense molecular clouds, the interstellar medium most relevant to star formation process, as well as future prospects., SPRINGER
    NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS, 1998, [Reviewed]
  • Molecular Clouds in Cepheus and Cassiopeia
    Y. Yonekura; K. Dobashi; A. Mizuno; H. Ogawa; Y. Fukui
    Astrophys. J. Suppl., May 1997, [Reviewed]
  • A large-scale (CO)-C-13 distribution of the galaxy - A global view of star forming clouds
    K Tachihara; Y Yonekura; A Kawamura; A Mizuno; H Ogawa; Y Fukui, A large-scale (CO)-C-13 (J = 1-0) survey project is now on-going with two m millimeter-wave radio telescopes of Nagoya University. The purpose of this survey is to reveal the distribution of dense moleclar clouds, probable sites of star formation, along the Galactic plane and to investigate the physical conditions for star formation. This survey covers all area of l similar to 0 degrees - 230 degrees and b similar to -20 degrees - 20 degrees, corresponding to similar to 6060deg(2). This includes nearby star-forming regions such as Orion, Taurus, Cepheus, Cygnus, Serpens, Ophiuchus, and Lupus. The find the (CO)-C-13 distribution is highly clumpy. By using this dataset, we identified individual clouds at 3 sigma noise level and catalogued more than 1000 clouds having a wide mass range of similar to 10(1-4)M.. In this contribution, we briefly describe the results, focusing on the following three aspects; (1) mass spectra of star forming molecular clouds, (2) gravitational stabilities of these clouds, and (3) their star forming activities. At the end, we give a prospect on the southern sky survey to be made with the 4 m telescope recently installed at the Las Campanas Observatory in Chile., KLUWER ACADEMIC PUBL
    IMPACT OF LARGE SCALE NEAR-IR SKY SURVEYS, 1997, [Reviewed]
  • OVERALL DISTRIBUTION OF DENSE MOLECULAR GAS AND STAR-FORMATION IN THE TAURUS CLOUD COMPLEX
    A MIZUNO; T ONISHI; Y YONEKURA; T NAGAHAMA; H OGAWA; Y FUKUI, We carried out a survey for dense molecular clouds in the Taurus complex in the (CO)-C-13 (J = 1-0) molecular emission at 2.7 mm wavelength with two 4 m millimeter-wave telescopes at Nagoya University. We obtained 37,720 spectra at a 1'.9 (l) x 2'.0 (b) grid spacing with a 2'.7 beam. Total molecular mass is estimated to be similar to 6800 M(.). There are three massive clouds, HCL2, B18, and L1495, and 13 small molecular clouds. Most of the clouds are connected with each other at a low intensity level. Among 94 young stellar objects (YSOs) identified in the Taurus complex, 59 are revealed to be associated with dense clouds having molecular column density greater than 3 x 10(21) cm(-2). Molecular gas of highest column density is associated with the youngest invisible protostellar objects, suggesting that star formation takes place in gas with high column density. Fifty of the 59 YSOs are associated with the massive clouds, and the remaining nine YSOs with the small clouds. Star formation efficiencies both in the massive and small clouds show similar values, suggesting that we may not neglect the contribution of small clouds toward global star formation. The basic structure of the molecular gas is filamentary, and we identified similar to 30 filamentary components distributed as a network. This suggests the importance of the process of gas condensation into a filamentary shape., IOP PUBLISHING LTD
    ASTROPHYSICAL JOURNAL, Jun. 1995, [Reviewed]
  • A NEW LOOK AT THE DARK CLOUD L1251 - SENSITIVE OBSERVATIONS OF THE MOLECULAR-EMISSION
    F SATO; A MIZUNO; T NAGAHAMA; T ONISHI; Y YONEKURA; Y FUKUI, High-sensitivity observations in the (CO)-C-12, (CO)-C-13, (CO)-O-18, (HCO+)-C-13, and SiO lines have been made of the dark cloud L1251 in Cepheus. The (CO)-C-13 gas shows a cometary distribution with a U-shaped dense ''head'' having a highly ordered velocity gradient in the direction parallel to the minor axis of the cloud. Five (CO)-O-18 cores characterized by a mass of similar to 50 M. and a mean density of similar to 3 x 10(3) cm(-3) are embedded in the (CO)-C-13 cloud. Three of them have associated far-infrared sources, suggesting that stars have recently formed there. High angular resolution (CO)-C-12 observations have revealed a well-collimated compact outflow confined in the most massive, densest (CO)-O-18 core. Its driving source is embedded in a small (HCO+)-C-13 core With a mass of similar to 1-3 M.. A possibility is suggested that the U shape of the cloud and its well-defined velocity gradient may have resulted from some dynamical interaction with the ambient matter., UNIV CHICAGO PRESS
    ASTROPHYSICAL JOURNAL, Nov. 1994, [Reviewed]
  • Unbiased surveys for dense cloud cores
    Y Fukui; A Mizuno; H Ogawa; K Dobashi; T Nagahama; JP Bernard; T Tsuboi; T Onishi; Y Yonekura, EDITIONS FRONTIERES
    COLD UNIVERSE, 1994, [Reviewed]
  • (CO)-C-12 AND (CO)-C-13 OBSERVATIONS OF THE DARK CLOUD COMPLEX NEAR IC5146
    K DOBASHI; Y YONEKURA; A MIZUNO; Y FUKUI, A large scale survey of a dark cloud complex in the vicinity of IC5146 has been made in the (CO)-C-12(J = 1 - 0) and (CO)-C-13(J = 1 - 0) emission lines. 3000 spectra were obtained with 2' grid spacing for each line for an area of approximately 3-degrees X 2-degrees. Five CO clouds and fifteen (CO)-C-13 clumps are identified, and physical parameters such as mass, temperature, density of H-2 Molecules are derived for each clump. Total molecular mass of the dark cloud complex is estimated to be approximately 4500M. by assuming LTE, about 50% larger than that of the Taurus complex. The clumps are found to be nearly in virial equilibrium. There are 18 candidates for the young stellar objects in the region, and 13 of them are concentrated into two (CO)-C-13 clouds. Most active star formation is found in the most massive member of the complex having molecular mass of -2200M.. The cloud consists of two (CO)-C-13 clumps, whose masses are approximately 1 X 10(3)M., respectively, and is associated with six candidates for the young stellar objects. The velocity distribution of the entire cloud complex is characterized by a velocity gradient of 0.17 km s-1 pc-1 along the elongation of the complex over 2-degrees, in addition to a velocity gradient of approximately 0.27 km s-1 pc-1 orthogonal to the elongation at some places., AMER INST PHYSICS
    ASTRONOMICAL JOURNAL, Oct. 1992, [Reviewed]

MISC

  • Japanese VLBI Network observation of NVSS J151100+054916 near new gamma-ray source found in the positional error of high-energy neutrino event IceCube-191119A               
    K. Niinuma; Y. Yonekura; K. Motogi; K. Fujisawa; K. Ohta; and K. Kawabata
    The Astronomer's Telegram, 24 Dec. 2019
  • Bursting activity of the 6.668-GHz CH3OH maser detected in G 358.93-00.03 using the Hitachi 32-m               
    K. Sugiyama; Y. Saito; Y. Yonekura; and M. Momose
    The Astronomer's Telegram, 29 Jan. 2019
  • MAXI and NICER observations of a long flare from UX Ari               
    W. Iwakiri; R. Sasaki (Chuo U.); K. Gendreau; Z. Arzoumanian; M. F. Corcoran; K. Hamaguchi (NASA/GSFC); Y. Tsuboi; H. Kawai; T. Sato (Chuo U.); T. Mihara; S. Nakahira (RIKEN); M. Serino (AGU); H. Negoro (Nihon U.); M. Shidatsu (Ehime U.); T. Enoto (Kyoto U.); Y. Yonekura (Ibraki U.); K. Fujisawa; K. Niinuma; T. Aoki; Y. Furuya; K. Shiotani; Y. Kojima; S. Sukehiro; Y. Imaizumi; T. Ogura; A. Hirano; K. Fujimoto; M. Nakamura; K. Mori (Yamaguchi U.); T. Umemoto (NRO); K. Takefuji (NICT)
    The Astronomer's Telegram, 29 Nov. 2018
  • 6.7-GHz observations of the RS CVn type star HR1099 after the large X-ray flare               
    K. Takefuji; Y. Yonekura; K. Niinuma; H. Kawai; and Y. Tsuboi
    The Astronomer's Telegram, 27 Sep. 2017
  • Moderate flux rises of 6.668-GHz CH3OH maser related to the H2O maser bursts in G 025.65+01.05 using the Hitachi 32-m               
    K. Sugiyama; Y. Saito; H. Akitaya; Y. Yonekura; and M. Momose
    The Astronomer's Telegram, 19 Sep. 2017
  • AMANOGAWA-2SB survey: a northern galactic plane survey in 12CO (J = 2 - 1) and 13CO (J = 2 - 1) with the Amanogawa telescope               
    T. Handa; T. Yoda; K. Kohno; T. Nakajima; J. Morino; Y. Yonekura; H. Ogawa; K. Kimura; K Dobashi
    Proceedings of the International Astronomical Union, Mar. 2013
  • 45m鏡搭載用100GHz帯導波管型両偏波・2SB超伝導受信機の開発
    川村雅之; 中島拓; 木村公洋; 米倉覚則; 小川英夫; 酒井剛; 久野成夫; 川辺良平; 浅山信一郎; 野口卓; 坪井昌人
    日本天文学会年会講演予稿集, 20 Feb. 2008
  • Development of a waveguide-type dual-polarization sideband-separating SIS receiver system in 100 GHz band for the NRO 45-m telescope
    Taku Nakajima; Takeshi Sakai; Shin'ichiro Asayama; Kimihiro Kimura; Masayuki Kawamura; Yoshinori Yonekura; Hideo Ogawa; Nario Kuno; Takashi Noguchi; Masato Tsuboi; Ryohei Kawabe
    Proceedings of the 19th International Symposium on Space Terahertz Technology, ISSTT 2008, 2008, [Reviewed]
  • ASTRO‐G/VSOP‐2搭載用8GHz帯マルチモードホーンの開発
    利川達也; 黒住聡丈; 城山典久; 木村公洋; 阿部安宏; 米倉覚則; 小川英夫; 氏原秀樹; 三谷友彦; 橋本弘藏; 村田泰宏; 坪井昌人; 春日隆
    日本天文学会年会講演予稿集, 20 Aug. 2007
  • ASTRO‐G搭載用8GHz帯常温HEMTアンプの開発~導波管入力型~
    黒住聡丈; 阿部安宏; 小嶋崇文; 川村雅之; 城山典久; 利川達也; 木村公洋; 中島拓; 米倉覚則; 小川英夫; 村田泰宏; 坪井昌人; 春日隆
    日本天文学会年会講演予稿集, 20 Aug. 2007
  • Molecular loops in the Galactic centre; Evidence for magnetic floatation accelerating molecular gas
    H. Yamamoto; Y. Fukui; M. Fujishita; K. Torii; N. Kudo; S. Nozawa; K. Takahashi; K. Takahashi; R. Matsumoto; M. MacHida; A. Kawamura; Y. Yonekura; N. Mizuno; T. Onishi; A. Mizuno
    Proceedings of the International Astronomical Union, 01 Aug. 2006
  • High-Mass Cloud Cores in the η Carinae Giant Molecular Cloud
    Y. Yonekura; S. Asayama; K. Kimura; H.Ogawa; Y. Kanai; N. Yamaguchi; Peter J. Barnes; Y. Fukui
    The Astrophysical Journal, 2005
  • Study of molecular clouds and star formation in the region of IC 2118
    M Kun; H Aoyama; N Yoshikawa; A Kawamura; Y Yonekura; T Onishi; Y Fukui
    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Dec. 2001
  • A New Look at CO Outflows in the Dark Cloud Complex near IC 5146               
    K. Dobashi; Y. Yonekura; Y. Hayashi
    Publications of the Astronomical Society of Japan, Dec. 2001
  • 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. Oagwa
    Publications of the Astronomical Society of Japan, Jun. 2001
  • The Most Luminous Protostars in Molecular Clouds               
    K. Dobashi; Y. Yonekura; F. Sato; J.P. Bernard; H. Ogawa
    Proceedings of the 33rd ESLAB Symp."Star Formation from the Small to the Large Scale" (ESA, Noordwijk), Oct. 2000
  • A Survey of Molecular Clouds at Nagoya University               
    A. Kawamura; T. Onishi; Y. Yonekura; K. Dobashi; A. Mizuno; H. Ogawa; Y. Fukui
    Proceedings of Star Formation 1999 (Nagoya Univ., Nagoya),, Dec. 1999
  • A 13CO Survey of Molecular Clouds in Gemini and Auriga               
    A. Kawamura; T. Onishi; Y. Yonekura; K. Dobashi; A. Mizuno; H. Ogawa; Y. Fukui
    Astrophysical Journal Suppl., Jul. 1998
  • A Head-Tail-Structured Molecular Cloud and a CO Outflow Associated with IRAS 22103+5828 in S134               
    Y. Yonekura; K. Dobashi; Y. Hayashi; H. Ogawa; Y. Fukui
    Astronomical Journal, May 1998
  • Molecular Clouds in Cygnus. I. A Large Scale13CO Survey               
    K. Dobashi; J.P. Bernard; Y. Yonekura; Y. Fukui
    Astrophysical Journal Suppl., Dec. 1994
  • A Large Scale13CO(J=1-0) Survey in Cygnus               
    K. Dobashi; J.P. Bernard; Y. Yonekura; A. Mizuno; H. Ogawa; Y. Fukui
    the Abstract of the XXIVth General Assembly of the International Union of Radio Science (URSI, Kyoto), Aug. 1993

Books and other publications

  • シリーズ現代の天文学 第6巻 星間物質と星形成               
    福井康雄; 犬塚修一郎; 大西利和; 中井直正; 舞原俊憲; 水野亮編, Joint work
    日本評論社, Sep. 2008

Lectures, oral presentations, etc.

  • Detection of the longest periodic variability in 6.7 GHz methanol masers with iMet               
    Yoshihiro Tanabe and Yoshinori Yonekura (Ibaraki U.)
    International Astronomical Union Symposium 380: Cosmic Masers: Proper Motion toward the Next-Generation Large Projects, 23 Mar. 2023
    20230320, 20230324
  • The water and methanol masers in the face-on accretion system around the high-mass protostar G353.273+0.641               
    Kazuhito Motogi (Yamaguchi U.); Tomoya Hirota (NAOJ; SOKENDAI); Masahiro N. Machida (Kyusyu U.); Kei E. I. Tanaka (Titech); Yoshinori Yonekura (Ibaraki U.)
    International Astronomical Union Symposium 380: Cosmic Masers: Proper Motion toward the Next-Generation Large Projects, 22 Mar. 2023
    20230320, 20230324
  • The Astrometric Animation of Water Masers toward the Mira Variable BX Cam               
    Shuangjing XU (KASI; SHAO); Hiroshi IMAI (Kagoshima U.); Youngjoo YUN (KASI); Bo ZHANG (SHAO); María J. RIOJA (CSIRO; IGN); Richard DODSON (ICRAR); Se-Hyung CHO (SNU; KASI); Jaeheon KIM (KASI); Lang CUI (XAO); Andrey M. SOBOLEV (UFU); James O. CHIBUEZE (NWU; U. Nigeria); Dong-Jin KIM (MIT; MPIfR); Kei AMADA (Kagoshima U.); Jun-ichi NAKASHIMA (Sun Yat-sen U.); Gabor OROSZ (JIVE); Miyako OYADOMARI (Kagoshima U.); Sejin OH (KASI); Yoshinori YONEKURA (Ibaraki U.); Yan SUN (SHAO; UCAS); Xiaofeng MAI (SHAO; UCAS); Jingdong ZHANG (SHAO; UCAS); Shiming WEN (SHAO); and Taehyun JUNG (KASI)
    International Astronomical Union Symposium 380: Cosmic Masers: Proper Motion toward the Next-Generation Large Projects, 21 Mar. 2023
    20230320, 20230324
  • High-cadence 6.7 GHz methanol maser monitoring observations by Hitachi 32-m radio telescope               
    Yoshinori Yonekura; Yoshihiro Tanabe; and Ren Moriizumi (Ibaraki U.)
    International Astronomical Union Symposium 380: Cosmic Masers: Proper Motion toward the Next-Generation Large Projects, 20 Mar. 2023
    20230320, 20230324
  • 大質量星形成領域 G24.33+0.14 におけるミリ波メタノール輝線の増光               
    廣田朋也、砂田和良 、BURNS Ross A. (国立天文台)、金美京 (大妻女子大学)、元木業人 (山口大学)、 杉山孝一郎 (タイ国立天文学研究所)、米倉覚則 (茨城大学)、Maser Monitoring Organization (M2O)
    日本天文学会2023年春季年会, 16 Mar. 2023, 日本天文学会
    20230313, 20230316
  • 高萩・日立 32 m 電波望遠鏡の整備運用・状況 2023A               
    米倉覚則; 田辺義浩; 森泉怜; 百瀬宗武 (茨城大); 知念翼; 孫赫陽; 抱江柊利; 小川英夫 (大阪公大); 清 水祐亮; 元木業人; 新沼浩太郎; 藤沢健太 (山口大); 須藤広志 (岐阜大); 久野成夫 (筑波大); 中川亜紀 治 (鹿児島大); 本間希樹; 小林秀行 (国立天文台); 他 JVN 関係者; 近藤哲朗
    日本天文学会2023年春季年会, 14 Mar. 2023, 日本天文学会
    20230313, 20230316
  • 茨城観測局電波望遠鏡搭載広帯域 CX 帯円偏波分離器の開発 4               
    知念翼; 孫赫陽; 抱江柊利; 米山翔; 川下紗奈; 増井翔; 山崎康正; 野曽原千晟; 長谷川豊; 澤田-佐藤聡 子; 岡田望; 小川英夫; 大西利和 (大阪公立大学); 米倉覚則 (茨城大学); 清水裕亮; 松原空洋; 新沼浩太 郎; 藤澤健太 (山口大学)
    日本天文学会2023年春季年会, 13 Mar. 2023, 日本天文学会
    20230313, 20230316
  • High-cadence 6.7 GHz methanol maser monitoring observations by Hitachi 32-m radio telescope               
    Yoshinori Yonekura (Ibaraki University)
    A half century of millimeter and submillimeter astronomy: Impact on astronomy/astrophysics and the future, 15 Dec. 2022
    20221215, 20221218
  • 茨城観測局電波望遠鏡搭載広帯域 CX 帯受信機の開発 3               
    知念翼; 孫赫陽; 抱江柊利; 米山翔; 川下紗奈; 増井翔; 山崎康正; 野曽原千晟; 長谷川豊; 澤田-佐藤聡 子; 小川英夫; 大西利和 (大阪公立大学); 岡田望 (JAXA); 米倉覚則 (茨城大学); 清水裕亮; 新沼浩太郎; 藤澤健太 (山口大学)
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • 広帯域 CX 帯同軸導波管変換の開発とそれを用いた TRL 校正               
    抱江柊利; 孫赫陽; 野曽原千晟; 知念翼; 米山翔; 川下紗奈; 山崎康正; 増井翔; 長谷川豊; 澤田-佐藤聡子; 大西利和; 小川英夫 (大阪公立大学); 米倉覚則 (茨城大学); 清水裕亮; 新沼浩太郎; 藤澤健太 (山口大学)
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • 茨城観測局電波望遠鏡搭載広帯域 CX 位相遅延器の開発               
    孫赫陽; 抱江柊利; 野曽原千晟; 知念翼; 米山翔; 川下紗奈; 山崎康正; 増井翔; 長谷川豊; 澤田-佐藤聡子; 大西利和; 小川英夫 (大阪公大); 米倉覚則 (茨城大); 清水裕亮; 新沼浩太郎; 藤澤健太 (山口大)
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 2022B               
    米倉覚則; 田辺義浩; 森泉怜; 百瀬宗武 (茨城大); 知念翼; 増井翔; 山崎康正; 孫赫陽; 抱江柊利; 小川英 夫 (大阪公大); 岡田望 (JAXA); 清水祐亮; 元木業人; 新沼浩太郎; 藤沢健太 (山口大); 須藤広志 (岐阜 大); 久野成夫 (筑波大); 中川亜紀治 (鹿児島大); 本間希樹; 小林秀行 (国立天文台); 他 JVN 関係者
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • HINOTORI (Hybrid Integration Project in Nobeyama, Triple-band Oriented) 進捗報告               
    今井 裕; 新永浩子; 甘田 渓; 松坂 怜; 中島圭佑; 沈 嘉耀(鹿児島大学); 新沼浩太郎; 清水祐亮(山口大学); 小川英夫; 澤田佐藤聡子; 米山 翔(大阪公立大学); 小山友明; 西村 淳; 宮澤千栄子; 高橋敏一; 亀野誠二; 廣田朋也(国立天文台); 岡田 望 (JAXA); 米倉覚則(茨城大学)
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • 野辺山 45 m 鏡 eQ 受信機のコミッショニング観測結果               
    山崎康正 (大阪公大); 中村文隆 (NAOJ); Chau-Ching Chiong (ASIAA); 西村淳 (NRO); Ross Burns; 谷口琴美; 川邊良平 (NAOJ); 米山翔; 川下紗奈; 知念翼; 西本晋平; 野曽原千晟; 孫赫陽; 小西亜侑; 小川英夫; 大西利和 (大阪公大); 米倉覚則 (茨城大); 土橋一仁 (東京学芸大); 下井倉ともみ (大妻女子大) ほか eQ チーム
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • 臼田 64 m アンテナを用いた FRB 20201124A からの 2 GHz における高フルエンスバースト検出               
    池邊蒼太 (東大/国立天文台); 岳藤一宏; 村田泰宏; 竹内央 (JAXA); 寺澤敏夫 (東大); 本間希樹; 赤堀卓也; 吉浦伸太郎; 鈴木駿策; 小山友明 (国立天文台); Eie Sujin(東大/国立天文台); 橋本哲也 (国立中興大学); 木坂将大 (広島大); 榎戸輝揚 (理研); 米倉覚則 (茨城大); 新沼浩太郎 (山口大); 関戸衛 (NICT)
    日本天文学会2022年秋季年会, 14 Sep. 2022, 日本天文学会
    20220913, 20220915
  • eQ NRO45 observations of the G358.93-0.03 high-mass star forming region               
    Ross Burns (NAOJ) Yasumasa Yamazaki (Osaka Public Univ.); Fumitaka Nakamura (NAOJ); Chau-Ching Chiong (ASIAA); Atsushi Nishimura (NRO); Kotomi Taniguchi; Ryohei Kawabe (NAOJ); Sho Yoneyama; Sana Kawashita; Tsubasa Chiken; Shinpei Nishimoto; Chiaki Nosohara; Ayo Son; Ayu Konishi; Hideo Ogawa; Toshikazu Onishi (Osaka Public Univ.); Kennori Yonekura (Ibaraki Univ.); Kazuhito Dobashi (Tokyo Gakugei Univ.); Tomomi Shimoikura (Otsuma Women’s Univ.); eQ Team members
    日本天文学会2022年秋季年会, 13 Sep. 2022, 日本天文学会
    20220913, 20220915
  • 周期的な強度変動を示す 6.7 GHz メタノールメーザーに対するなゆた望遠鏡を用いた近赤外線モニター観測 I               
    田辺義浩; 米倉覚則(茨城大学); 土橋一仁; 荒川琉嘉(東京学芸大学); 岩田悠平(国立天文台); 杉山孝一郎(タイ国立天文学研究所); 内山瑞穂(宇宙航空研究開発機構); 高山正輝(兵庫県立大学)
    日本天文学会2022年秋季年会, 13 Sep. 2022, 日本天文学会
    20220913, 20220915
  • JVN 山口-日立基線 VLBI を用いた超高エネルギーガンマ線 AGN 候補天体の探査               
    藤田大輔; 新沼浩太郎; 藤澤健太; 元木業人 (山口大学); 米倉覚則 (茨城大学)
    日本天文学会2022年秋季年会, 13 Sep. 2022, 日本天文学会
    20220913, 20220915
  • Hitachi and Takahagi 32-m radio telescopes: recent updates               
    Yoshinori Yonekura; Yoshihiro Tanabe (Ibaraki University; Japan); Kenta Fujisawa; Kotaro Niinuma (Yamaguchi University; Japan); Hideo Ogawa (Osaka Metropolitan University; Japan); Koichiro Sugiyama (National Astronomical Research Institute of Thailand; Thailand); Kazuhiro Takefuji (USUDA Deep Space Center; JAXA; Japan); Mareki Honma; Hideyuki Kobayashi (Mizusawa VLBI Observatory; National Astronomical Observatory of Japan; The Graduate University for Advanced Studies (SOKENDAI); Japan); and members of JVNK
    2022 URSI-Japan Radio Science Meeting, 01 Sep. 2022, the Japan National Committee of URSI
    20220901, 20220902
  • 多波長同時観測で迫るおひつじ座 UX 星で生じた巨大フレアの特徴 (2)               
    北古賀智紀; 坪井陽子; 岩切渉; 河合広樹; 佐々木亮 (中央大学); 米倉覚則 (茨城大学); 岳藤一宏 (JAXA); 新沼浩太郎; 元木業人; 藤沢健太; 青木貴弘 (山口大学); 下条圭美; 梅本智文 (NAOJ)
    日本天文学会2022年春季年会, 03 Mar. 2022, 日本天文学会
    20220302, 20220305
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 2022A               
    米倉 覚則; 田辺 義浩; 岩田 悠平; 岡田 望; 伊藤 美穂; 高木 奏人; 永野 稜大; 百瀬 宗武 (茨城大); 知念 翼; 増井 翔; 山崎 康正; 孫 赫陽; 抱江 柊利; 小川 英夫 (大阪府大); 元木 業人; 新沼 浩太郎; 藤沢 健太 (山口大); 須藤 広志 (岐阜大); 久野 成夫 (筑波大); 中川 亜紀治 (鹿児島大); 本間 希樹; 小林 秀行 (国立天文台); 他大学間連携 VLBI group
    日本天文学会2022年春季年会, 02 Mar. 2022, 日本天文学会
    20220302, 20220305
  • 茨城観測局電波望遠鏡搭載広帯域 CX 帯円偏波分離器の開発 2               
    知念翼; 孫赫陽; 抱江柊利; 米山翔; 川下紗奈; 増井翔; 山崎康正; 野曽原千晟; 小川英夫; 大西利和 (大阪府大); 岡田望; 米倉覚則 (茨城大); 清水祐亮; 新沼浩太郎; 藤澤健太 (山口大); 金子慶子; 神澤富雄; 三ツ井健司 (国立天文台)
    日本天文学会2022年春季年会, 02 Mar. 2022, 日本天文学会
    20220302, 20220305
  • 野辺山45m鏡に搭載されたeQ受信機計画の概要と現状               
    中村文隆(NAOJ)、Chau-Ching Chiong (ASIAA)、西村淳(NRO)、Ross Burns、谷口琴美、川邊良平、藤井泰範(NAOJ)、山崎康正、小川英夫(大阪府立大)、米倉覚則(茨城大)、土橋一仁(東京学芸大)、下井倉ともみ(大妻女子大)ほかeQチーム
    日本天文学会2022年春季年会, 02 Mar. 2022, 日本天文学会
    20220302, 20220305
  • 野辺山 45 m 鏡 eQ 受信機の搭載及び光学系の評価               
    山崎康正 (大阪府大)、中村文隆 (NAOJ)、Chau-Ching Chiong (ASIAA)、西村淳 (NRO)、Ross Burns、谷口琴美、川邊 良平 (NAOJ)、米山翔、川下紗奈、知念翼、小西亜侑、西本晋平、孫赫陽、小川英夫、大西利和 (大阪府大)、米倉覚則 (茨城大)、土橋一仁 (東京学芸大)、 下井倉ともみ (大妻女子大) ほか eQ チーム
    日本天文学会2022年春季年会, 02 Mar. 2022, 日本天文学会
    20220302, 20220305
  • Multiple wavelengths observation of large stellar flares on the active RS CVn-type star UX Ari with MAXI, NICER, Ibaraki-Yamaguchi radio interferometer, and CAT               
    Satoki Kitakoga; Yohko Tsuboi; Wataru Iwakiri; Hiroki Kawai; Ryo Sasaki (Chuo University); Yoshinori Yonekura (Ibaraki University); Kazuhiro Takefuji (JAXA); Kenta Fujisawa; Kotaro Niinuma; Takahiro Aoki; Kazuhito Motogi (Yamaguchi University); Masumi Shimojo; Tomohumi Umemoto (NAOJ)
    Particle Acceleration in Solar Flares and the Plasma Universe -- Deciphering its features under magnetic reconnection, 18 Nov. 2021, IPMU, Univ. Tokyo
    20211115, 20211118
  • ALMA による重力不安定な円盤を伴う大質量原始星からの分子ガスアウトフロー観測               
    元木業人 (山口大学); 廣田朋也 (国立天文台); 町田正博 (九州大学); 米倉覚則 (茨城大学); 本間希樹 (国立天文台); 高桑繁久 (鹿児島大学); 松下聡樹 (ASIAA)
    日本天文学会2021年秋季年会, 15 Sep. 2021, 日本天文学会
    20210913, 20210915
  • 茨城観測局電波望遠鏡搭載広帯域 CX 帯円偏波分離器の開発               
    知念翼; 米山翔; 川下紗奈; 増井翔; 山崎康正; 長谷川豊; 大西利和; 小川英夫 (大阪府立大学); 米倉覚則 (茨城大学); 清水裕亮; 新沼浩太郎; 藤澤健太 (山口大学)
    日本天文学会2021年秋季年会, 15 Sep. 2021, 日本天文学会
    20210913, 20210915
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 2021B               
    米倉覚則; 田辺義浩; 岩田悠平; 伊藤美穂; 高木奏人; 永野稜大; 百瀬宗武 (茨城大); 知念翼; 増井翔; 山崎康正; 小川英夫 (大阪府大); 元木業人; 新沼浩太郎; 藤沢健太 (山口大); 須藤広志 (岐阜大); 久野成夫 (筑波大); 中川亜紀治 (鹿児島大); 本間希樹; 小林秀行 (国立天文台); 他大学間連携 VLBI group
    日本天文学会2021年秋季年会, 15 Sep. 2021, 日本天文学会
    20210913, 20210915
  • 多波長同時観測で迫るおひつじ座 UX 星で生じた巨大フレアの特徴               
    北古賀智紀; 岩切渉; 坪井陽子; 河合広樹; 佐々木亮 (中央大学); 米倉覚則 (茨城大学); 岳藤一宏 (JAXA); 新沼浩太郎; 青木貴弘; 元木業人; 藤沢健太 (山口大学); 下条圭美; 梅本智文 (NAOJ)
    日本天文学会2021年春季年会, 19 Mar. 2021, 日本天文学会
    20210316, 20210319
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 2021A               
    米倉 覚則; 田辺 義浩; 上地 康仁; 川上 泰輝; 平原 慶裕; 渡辺 雅人; 伊藤 美穂; 高木 奏人; 永野 稜大; 百瀬 宗武 (茨城大); 小川 英夫 (大阪府大); 藤沢 健太 (山口大); 須藤 広志 (岐阜大); 久野 成夫 (筑波大); 中川 亜紀治 (鹿児島大); 本間 希樹; 小林 秀行 (国立天文台); 他大学間連携 VLBI group
    日本天文学会2021年春季年会, 18 Mar. 2021, 日本天文学会
    20210316, 20210319
  • VERA と ALMA を用いた大質量原始星 S255 NIRS 3 における水メーザー観測               
    廣田朋也; Burns; Ross A.; 砂田和良 (国立天文台); Cesaroni; Riccardo; Moscadelli; Luca (アルチェトリ天文台); 杉山孝一郎 (タイ国立天文研究所); Kim; Jungha (韓国天文研究院); 米倉覚則 (茨城大学)
    日本天文学会2021年春季年会, 17 Mar. 2021, 日本天文学会
    20210316, 20210319
  • かにパルサーの巨大電波パルスに伴う X 線超過の発見               
    榎戸輝揚 (理研); 寺澤敏夫 (東京大; 国立天文台); 木坂将大 (広島大); Chin-Ping Hu(National Changhua Univ. of Education; 理研); 村田泰宏; 竹内央 (ISAS/JAXA); 岳藤一宏 (UDSC/JAXA; NICT); 関戸 衛 (NICT); 米倉覚則 (茨城大); 三澤浩昭; 土屋史紀 (東北大); 青木貴弘 (山口大); 徳丸宗利 (名古屋大); 本間希樹; 亀谷收; 小山友明 (国立天文台); 浅野勝晃 (東京大); 柴田晋平 (山形大); 田中周太 (青山学院大); Zaven Arzoumanian; Keith C. Gendreau(NASA/GSFC); and the NICER collaboration
    日本天文学会2021年春季年会, 16 Mar. 2021, 日本天文学会
    20210316, 20210319
  • かにパルサーの巨大電波パルスに伴う X 線超過の理論モデル               
    木坂将大 (広島大); 榎戸輝揚 (理研); 寺澤敏夫 (東京大; 国立天文台); Chin-Ping Hu(National Changhua Univ. of Education; 理研); 村田泰宏; 竹内央 (ISAS/JAXA); 岳藤一宏 (UDSC/JAXA; NICT); 関戸 衛 (NICT); 米倉覚則 (茨城大); 三澤浩昭; 土屋史紀 (東北大); 青木貴弘 (山口大); 徳丸宗利 (名古屋大); 本間希樹; 亀谷收; 小山友明 (国立天文台); 浅野勝晃 (東京大); 柴田晋平 (山形大); 田中周太 (青山学院大); Zaven Arzoumanian; Keith C. Gendreau(NASA/GSFC); and the NICER collaboration
    日本天文学会2021年春季年会, 16 Mar. 2021, 日本天文学会
    20210316, 20210319
  • かにパルサーの巨大電波パルス: X 線との相関解析のためのデータベース概要               
    寺澤敏夫 (東京大; 国立天文台); 榎戸輝揚 (理研); 木坂将大 (広島大); Chin-Ping Hu(National Changhua Univ. of Education; 理研); 村田泰宏; 竹内央 (ISAS/JAXA); 岳藤一宏 (UDSC/JAXA; NICT); 関戸 衛 (NICT); 米倉覚則 (茨城大); 三澤浩昭; 土屋史紀 (東北大); 青木貴弘 (山口大); 徳丸宗利 (名古屋大); 本間希樹; 亀谷收; 小山友明 (国立天文台); 浅野勝晃 (東京大); 柴田晋平 (山形大); 田中周太 (青山学院大); Zaven Arzoumanian; Keith C. Gendreau(NASA/GSFC); and the NICER collaboration
    日本天文学会2021年春季年会, 16 Mar. 2021, 日本天文学会
    20210316, 20210319
  • メタノールメーザーにおける電波と光の共同観測               
    米倉覚則
    第11回光赤外線天文学大学間連携ワークショップ, 11 Nov. 2020, [Invited]
    20201110, 20201112
  • 茨城32m鏡メタノールメーザー観測による大質量星形成時のaccretion burstの検出とフォローアップ観測               
    米倉覚則
    Nobeyama Science Workshop 2020, 15 Sep. 2020, [Invited]
    20200915, 20200916
  • 6-23 GHz 天文観測用超広帯域フィードアンテナの開発               
    長谷川 豊; 山崎 康正; 小川 英夫 ( 大阪府立大学 ); 川上 泰輝; 米倉 覚則 ( 茨城大学 ); 木村 公洋 ( JAXA ); 赤堀 卓也 ( NAOJ )
    日本天文学会2020年秋季年会, 10 Sep. 2020, 日本天文学会
    20200908, 20200910
  • 茨城 32-m 電波望遠鏡による 6.7 GHz メタノールメーザー源の単一鏡強度モニターを活用した突発現象天文学および大学教育               
    米倉 覚則; 齋藤 悠; 百瀬 宗武; 杉山 孝一郎
    日本天文学会2020年春季年会, Mar. 2020, 日本天文学会
  • 鹿島-日立VLBIによる核融合開始直後の大質量星に付随する極小HII領域の大規模探査               
    小倉達也; 元木業人; 青木貴弘; 新沼浩太郎; 藤沢健太; 米倉覚則; 関戸衛; 岳藤一宏
    日本天文学会2020年春季年会, Mar. 2020, 日本天文学会
  • OISTERと電波源突発現象とのシナジー               
    内山瑞穂; 杉山孝一郎; 米倉覚則; 藤沢健太
    日本天文学会2020年春季年会, Mar. 2020, 日本天文学会, [Invited]
  • ALMA Cycle 6による重力不安定な円盤を伴う大質量原始星からの分子ガスア ウトフロー観測               
    元木業人; 廣田朋也; 町田正博; 米倉覚則; 本間希 樹; 高桑繁久; 松下聡樹; ASIAA
    日本天文学会2020年春季年会, Mar. 2020, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (19)               
    米倉覚則; 齋藤悠; 佐藤公紀; 上地康仁; 川上泰輝; 平原慶裕; 渡辺雅人; 百瀬宗武; 小川 英夫; 藤沢 健太; 高羽 浩; 久野 成夫; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2019年秋季年会, Sep. 2019, 日本天文学会
  • 大質量星形成領域G 358.93-00.03における降着バースト的増光現象の検出               
    杉山孝一郎; 米倉覚則; 齋藤悠; 百瀬宗武; 廣田朋也; R. A. Burns; 本間希樹; 元木業人; 藤沢健太; G. C. MacLeod; HartRAO; O. S. Bayandina (RAS; J. Bra; INAF; X. Chen; Guangzhou Univ; S. Breen; iv. of; Sydn; M2O collaboration
    日本天文学会2019年秋季年会, Sep. 2019, 日本天文学会
  • ALMA Long BaselineによるFace-on大質量原始星候補天体の撮像観測2: 降着円盤               
    元木業人; 廣田朋也; 町田正博; 米倉覚則; 本間希 樹; 高桑繁久; 松下聡樹; ASIAA
    日本天文学会2019年秋季年会, Sep. 2019, 日本天文学会
  • SPART 10-m電波望遠鏡を用いた230 GHz国際ミリ波VLBI観測               
    青木貴弘; 前澤裕之; 増井翔; 岡田望; 西村淳; 築山大輝; 冨原彩加; 小川英夫; 新沼浩太郎; 甘利涼湖; 堤稔喜; 藤澤健太; 米倉覚則; 上地康仁; 井上允 (ASIAA; 立天文
    日本天文学会2019年秋季年会, Sep. 2019, 日本天文学会
  • 拡張相互相関分光法による6.7GHzメタノールメーザー解析               
    岳藤一宏; 米倉覚則; 齋藤悠; 青木貴弘; 藤澤健太; 杉山孝一郎; 今井裕
    日本天文学会2019年秋季年会, Sep. 2019, 日本天文学会
  • 銀河中心方向のコンパクト電波源の探査               
    助廣沙知; 藤沢健太; 米倉覚則
    日本天文学会2019年秋季年会, Sep. 2019, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (18)               
    米倉覚則; 齋藤悠; 佐藤公紀; 会川航平; 大島理穂; 齋藤偉; 百瀬宗武; 小川英夫; 藤沢 健太; 高羽 浩; 久野 成夫; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2019年春季年会, Mar. 2019, 日本天文学会
  • 6.7 GHzメタノールメーザーが付随する大質量原始星に対するCH3CN熱的輝線放射観測               
    石川果奈; 百瀬宗武; 米倉覚則; 杉山孝一郎; 塚越崇
    日本天文学会2019年春季年会, Mar. 2019, 日本天文学会
  • ALMA Long BaselineによるFace-on大質量原始星候補天体の撮像観測1: 回転降着エンベロープ               
    元木業人; 廣田朋也; 町田正博; 米倉覚則; 本間希樹; 高桑繁久; 松下聡樹; ASIAA
    日本天文学会2019年春季年会, Mar. 2019, 日本天文学会
  • 日韓 VLBI による、43GHz 帯偏波 VLBI 試験観測経過報告及び活動銀河核ジェット収束機構の研究               
    萩原喜昭; 河野祐介; 鈴木駿策; 秦和弘; 小山友明; 宇賀裕哉; 松枝知佳; 藤沢健太; 新沼浩太郎; 嶺重慎; 米倉覚則; 笹田真人
    日本天文学会2019年春季年会, Mar. 2019, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡を用いた対応天体探査の可能性について               
    米倉覚則; 齋藤悠; 百瀬宗武; 藤沢健太; 新沼浩太郎; 元木業人; 青木貴弘; 岳藤 一宏; 他大学間連携; LBI group
    日本天文学会2018年秋季年会, Sep. 2018, 日本天文学会
  • 大学 VLBI 連携観測網による突発天体の追観測体制               
    青木 貴弘; 元木 業人; 新沼 浩太郎; 藤沢 健太; 米倉 覚則; 齋藤 悠; 百瀬 宗武; 岳藤 一宏; 他大学間連携; LBI group
    日本天文学会2018年秋季年会, Sep. 2018, 日本天文学会
  • X 線、Hα 線、電波による巨大恒星フレアの同時多波長観測体制の構築               
    河合広樹; 坪井陽子; 米倉覚則; 岳藤一宏; 岩切渉; 佐々木亮; 梅本智文; 新沼浩太郎; 青木貴弘
    日本天文学会2018年秋季年会, Sep. 2018, 日本天文学会
  • 大質量原始星の近赤外線変光の検出               
    吉田 泰; 宮田 隆志; 内山 瑞穂; 杉山 孝一郎; 米倉 覚則; 斎藤 悠; 中岡竜也; 川端美穂; 黄 若晨; 川端弘治; 山中雅之; 伊藤亮介; 他広島大学かな; 観測チーム
    日本天文学会2018年秋季年会, Sep. 2018, 日本天文学会
  • VERA43GHz 帯用両偏波受信システムの開発と活動銀河核ジェットの生成・収束機構の研究               
    萩原喜昭; 河野祐介; 鈴木駿策; 秦和弘; 小山友明; 宇賀裕哉; 松枝知佳; 藤澤健太; 新沼浩太郎; 嶺重慎; 米倉覚則; 笹田真人
    日本天文学会2018年秋季年会, Sep. 2018, 日本天文学会
  • JVN 大規模電波源探査に向けた感度測定試験観測 2 コヒーレンス時間の実測               
    元木業人; 小倉達也; 青木貴弘; 新沼浩太郎; 藤沢健太; 米倉覚則; 関戸衛; 岳藤一宏
    日本天文学会2018年秋季年会, Sep. 2018, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (16)               
    米倉覚則; 齋藤悠; Kang-Lou SOON; 会川航平; 大島理穂; 齋藤偉; 青木健悟; 山口貴大; 百瀬宗武; 小川 英夫; 藤沢 健太; 高羽 浩; 中井 直正; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2018年春季年会, Mar. 2018, 日本天文学会
  • 気球 VLBI 地上振り子試験               
    河野裕介; 土居明広(JA; 木村公洋; 小山友明; 中原聡美(JA; 鈴木駿策; 保田大輔; 岡田望; 長谷川豊(JA; 亀谷收; 米倉覚則; 関戸衛(NICT; 村田泰弘(JA; 山下一芳; 松本尚子; 本間希樹
    日本天文学会2018年春季年会, Mar. 2018, 日本天文学会
  • JVN 大規模電波源探査に向けた感度測定試験観測               
    元木業人; 小倉達也; 青木貴弘; 新沼浩太郎; 藤沢健太; 米倉覚則; 関戸衛; 岳藤一宏
    日本天文学会2018年春季年会, Mar. 2018, 日本天文学会
  • 2017.11.7 Crab pulsar large glitch観測速報(1):概要               
    寺澤敏夫; 徳丸宗利; 俵海人; 岳藤一宏; 関戸衛; 三澤浩昭; 土屋史紀; 村田泰宏; 竹内 央; 米倉覚則; 青木貴弘; 新沼浩太郎; 藤澤健太; 本間希樹; 小山友明; 榎戸輝揚; 木 坂将大; 柴田晋平; 浅野勝晃; 田中周太; 理研; 情報通信研究機構; 宇宙航空研究開発機構; 国立天文台; 青山学院
    日本天文学会2018年春季年会, Mar. 2018, 日本天文学会
  • 2017.11.7 Crab pulsar large glitch観測速報(2):波形変化の有無検証               
    木坂将大; 榎戸輝揚; 寺澤敏夫; 徳丸宗利; 俵海人; 岳藤一宏; 関戸衛; 三澤浩昭; 土屋史紀; 村田泰宏; 竹内央; 米倉覚則; 青木貴弘; 新沼浩太郎; 藤澤健太; 本間希樹; 小山友明; 柴田晋平; 浅野勝晃; 田中周太; 理研; 情報通信研; 宇宙航空研究開発機構; 国立天文台
    日本天文学会2018年春季年会, Mar. 2018, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (16)               
    米倉覚則; 秋田谷洋; 齋藤悠; 青木健悟; 山口貴大; 會川航平; 大島理穂; 齋藤偉; 百瀬宗武; 小川 英夫; 藤沢 健太; 高羽 浩; 中井 直正; 面高 俊宏; 本間 希樹; 小林 秀行; 杉山 孝一郎; 他大学間連携; LBI group
    日本天文学会2017年秋季年会, Sep. 2017, 日本天文学会
  • 大阪府大 1.8 m 電波望遠鏡の K 帯給電系開発と気球 VLBI 実験               
    保田大介; 岡田望; 木村公洋; 小川英夫; 真鍋武嗣; 土居明広; 長谷川豊; 村田泰宏; ISA; 中原聡美; ISAS; 河野裕介; 小山友明; 亀谷收; 鈴木駿策; 米倉覚則; 関戸衛 (NIC
    日本天文学会2017年秋季年会, Sep. 2017, 日本天文学会
  • 野辺山 45m 電波望遠鏡複周波数バンド同時観測プロジェクト (Hybrid Installation Project in Nobeyama, Triple-band Oriented)               
    澤田-佐藤聡子; 今井裕; 半田利弘; 新永浩子; 水窪耕兵; 小川英夫; 真鍋武嗣; 木村公洋; 岡田望; 橋本育実; 南谷哲宏; 小山友明; 河野裕介; 砂田和良; 田村良明; 坂井伸行; 沢; VLBI 観測; 朝木義晴; 亀野誠二; 新沼浩太郎; 藤澤健太; 米倉覚則
    日本天文学会2017年秋季年会, Sep. 2017, 日本天文学会
  • 短基線 VLBI を用いた大質量原始星候補天体周囲の非定常電離ガス探査とモニター観測               
    元木業人; 新沼浩太郎; 青木貴弘; 藤沢健太; 米倉覚則; 杉山孝一郎
    日本天文学会2017年秋季年会, Sep. 2017, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (15)               
    米倉覚則; 杉山孝一郎; 齋藤悠; 青木健悟; 山口貴大; 足立弘; 大橋拓人; 佐藤宏樹; 柴田裕輝; 宮本 祐輔; 百瀬 宗武; 小川 英夫; 藤沢 健太; 高羽 浩; 中井 直正; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2017年春季年会, Mar. 2017, 日本天文学会
  • 臼田宇宙空間観測所 64m アンテナの電波天文観測に向けた性能評価               
    藏原昂平; 中西裕之; 今井裕; 齊田智恵; 村田泰宏; 坪井昌人; 研究所; 上原顕太; 石川聡一; 土橋一仁; 下井倉ともみ; 京学芸大; 藤沢健太; 青木貴弘; 山本宏昭; 米倉覚則; 春日隆
    日本天文学会2017年春季年会, Mar. 2017, 日本天文学会
  • 大質量星形成領域G9.62+0.20からの6.7 GHzメタノールメーザー放射に見られる周期強度変動要因の観測研究               
    佐藤宏樹; 杉山孝一郎; 齋藤悠; 米倉覚則; 百瀬宗武
    日本天文学会2017年春季年会, Mar. 2017, 日本天文学会
  • 3.8 m電波望遠鏡を用いたVLBI観測               
    高橋諒; 上田翔汰; 井上将徳; 岡田望; 長谷川豊; 木村公洋; 大西利和; 小川英夫; 米倉覚則; 藤澤健太; 徂徠和夫; 川畑亮二; 石本正芳; 福崎順洋; 近藤哲朗; ほか大学 VLBI; 連携グループ
    日本天文学会2017年春季年会, Mar. 2017, 日本天文学会
  • 気球 VLBI ミッションの検討 VII               
    土居明広; 宙航空研究開発機構; 河野裕介; 木村公洋; 松本尚子; 国立天文台; 岡田望; 馬場満久; 村田泰宏; 宙航空研究開発機構; 中原聡美; 小山友明; 鈴木駿策; 山下一芳; 中村拡; 米倉覚則; 亀谷收; 柴田克典; 本間希樹; 天文台; 関戸衛; 岳藤一宏; 報通信研究機構; ほか研究協力者
    日本天文学会2017年春季年会, Mar. 2017, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (14)               
    米倉 覚則; 齋藤 悠; 青木 健悟; 山口 貴大; 足立 弘; 大橋 拓人; 佐藤 宏樹; 柴田 裕輝; 宮本 祐輔; 杉山 孝一郎; 澤田-佐藤 聡子; 百瀬 宗武; 吉田 龍生; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2016年秋季年会, Sep. 2016, 日本天文学会
  • CORNISH HII 領域を対象とした 6.7 GHz メタノールメーザー探査に基づく大質量星形成過程の研究               
    柴田 裕輝; 杉山 孝一郎; 米倉 覚則; 百瀬 宗武
    日本天文学会2016年秋季年会, Sep. 2016, 日本天文学会
  • 日立 32-m 電波望遠鏡を用いた大規模な 6.7 GHz メタノール・メーザーモニターサーベイ: 1–2ヶ月周期天体の探査               
    杉山孝一郎; 米倉覚則; 齋藤悠; 佐藤宏樹; 宮本祐輔; 青木健悟; 山口貴大; 百瀬宗武; 元木業人; 本間希樹; 内山瑞穂; 蜂須賀一也; 藤沢健太; 稲吉恒平; 田中圭; 細川隆史
    日本天文学会2016年秋季年会, Sep. 2016, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (13)               
    米倉 覚則; 齋藤 悠; 沖本 有; 加古 琳一; 永瀬 桂; 安井 靖尭; 足立 弘; 大橋 拓人; 佐藤 宏樹; 柴田 裕輝; 宮本 祐輔; 杉山 孝一郎; 澤田-佐藤 聡子; 百瀬 宗武; 吉田 龍生; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2016年春季年会, Mar. 2016, 日本天文学会
  • 大質量原始星候補天体周囲の階層的降着構造に対する N2H+ 輝線観測               
    元木業人; Andrew; J. Walsh; 本間希樹; 廣田朋也; 新沼浩太郎; 蜂須賀一也; 徂徠和夫; 杉山孝一郎; 米倉覚則
    日本天文学会2016年春季年会, Mar. 2016, 日本天文学会
  • 日立 32-m 電波望遠鏡を用いた大規模な 6.7 GHz メタノール・メーザーモニターサーベイ: 短周期天体探査               
    杉山孝一郎; 米倉覚則; 齋藤悠; 永瀬桂; 安井靖尭; 佐藤宏樹; 宮本祐輔; 百瀬宗武; 元木業人; 本間希樹; 内山瑞穂; 藤沢健太; 蜂須賀一也; 稲吉恒平; 田中圭; 細川隆史
    日本天文学会2016年春季年会, Mar. 2016, 日本天文学会
  • G014.23-00.50 に付随する 6.7 GHz メタノールメーザーの高頻度モニター               
    永瀬桂; 安井靖尭; 杉山孝一郎; 米倉覚則; 百瀬宗武
    日本天文学会2016年春季年会, Mar. 2016, 日本天文学会
  • EAVN による 6.7 GHz メタノール・メーザーの VLBI サーベイ XI:ペア形状メーザー天体と多重原始星系               
    蜂須賀一也; 藤沢健太; 松本尚子; 国立天文台; 杉山孝一郎; 米倉覚則; 澤田-佐藤聡子; 元木業人; 村田泰宏(ISAS; JAXA)ほか
    日本天文学会2015年秋季年会, Sep. 2015, 日本天文学会
  • VLA による G353.273+0.641 周囲の階層的降着構造の発見               
    元木業人; 本間希樹; 廣田朋也; 立天文台; 新沼浩太郎; 蜂須賀一也; 藤沢健太; 徂徠和夫; 杉山孝一郎; 米倉覚則; Andrew; J. Walsh
    日本天文学会2015年秋季年会, Sep. 2015, 日本天文学会
  • 日立 32-m 電波望遠鏡を用いた大規模な 6.7 GHz メタノール・メーザーモニターサーベイ               
    杉山孝一郎; 米倉覚則; 齋藤悠; 永瀬桂; 安井靖尭; 佐藤宏樹; 宮本祐輔; 百瀬宗武; 元木業人; 本間希樹; 内山瑞穂; 藤沢健太; 蜂須賀一也; 稲吉恒平; 田中圭; 細川隆史
    日本天文学会2015年秋季年会, Sep. 2015, 日本天文学会
  • ダブルピーク広輝線を持つ電波銀河 3C332 の JVN による高分解能観測               
    中島大貴; 西川由恭; 徂徠和夫; 日浦皓一朗; 新沼浩太郎; 藤沢健太; 米倉覚則; 中井直正; 永井誠; 村田泰宏; 河野裕介; 小山友明
    日本天文学会2015年秋季年会, Sep. 2015, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (12)               
    米倉 覚則; 齋藤 悠; 沖本 有; 加古 琳一; 永瀬 桂; 安井 靖尭; 足立 弘; 大橋 拓人; 佐藤 宏樹; 柴田 裕輝; 宮本 祐輔; 杉山 孝一郎; 澤田-佐藤 聡子; 百瀬 宗武; 吉田 龍生; 近藤 哲朗; 関戸 衛; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 本間 希樹; 小林 秀行; 他大学間連携; LBI group
    日本天文学会2015年秋季年会, Sep. 2015, 日本天文学会
  • JVN による複数銀河核の高空間分解能探査観測:低赤方偏移の電波銀河               
    日浦皓一朗; 徂徠和夫; 中島大貴; 新沼浩太郎; 藤沢健太; 金子紘之; 澤田佐藤聡子; 米倉覚則; 河野裕介; 小山友明
    日本天文学会2015年秋季年会, Sep. 2015, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (11)               
    米倉 覚則; 齋藤 悠; Soon Kang Lo; 石井 翔太; 沖本 有; 永瀬 桂; 加古 琳一; 安井 靖尭; 杉山孝一郎; 宮本祐介; 百瀬 宗武; 吉田龍生; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 小林 秀行; 他大学間連携; VLBI group
    日本天文学会2015年春季年会, Mar. 2015, 日本天文学会
  • 近傍銀河 NGC 3079 中心領域のアンモニア分子吸収線観測2               
    宮本祐介; 中井直正; 瀬田益道; 久野成夫; Salak Dragan; 永井誠; 山内彩; 石井峻; 東; 米倉覚則
    日本天文学会2015年春季年会, Mar. 2015, 日本天文学会
  • ATCA による”face-on”大質量原始星候補天体の多周波観測– 7 mm 帯 –               
    元木業人; Andrew J. Walsh; Curtin University; 新沼浩太郎; 蜂須賀一也; 藤沢健太; 徂徠和夫; 杉山孝一郎; 米倉覚則; 本間希樹; 廣 田朋也
    日本天文学会2015年春季年会, Mar. 2015, 日本天文学会
  • EAVN による 6.7 GHz メタノール・メーザーの VLBI サーベイ X               
    杉山孝一郎; 藤沢健太; 蜂須賀一也; 元木業人; 平野大樹; 林京之介; 新沼浩太郎; 米倉覚則; 百瀬宗武; 齋藤悠; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 松本尚子; 村田泰宏; 土居明広; Shen, Zhiqiang; 小川英夫
    日本天文学会2015年春季年会, Mar. 2015, 日本天文学会
  • 多地点連携観測により得られたカニパルサー巨大電波パルスの広帯域スペクトル               
    三上諒; 寺澤敏夫; 浅野勝晃; 田中周太; 木坂将大; 関戸衛; 岳藤一宏; 川合栄治; 竹内央; 三澤浩昭; 土屋史紀; 北元; 米倉覚則; 亀谷收; 本間希樹; 藤沢健太; 新沼浩太郎; 青木貴弘
    日本天文学会2015年春季年会, Mar. 2015, 日本天文学会
  • 茨城観測局 高萩 / 日立 32 m 電波望遠鏡の立ち上げ               
    米倉 覚則; 齋藤 悠; Soon Kang Lou; 石井 翔太; 佐藤 雄貴; 沖本 有; 加古 琳一; 永瀬 桂; 安井 靖尭; 杉山 孝一郎; 宮本 祐介; 百瀬 宗武; 吉田 龍生; 横沢 正芳; 小川 英夫; 木村 公洋; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 亀野 誠二; 小山 友明; 河野 裕介; 小林 秀行; 川口 則幸; 他大学間連携; LBI group
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 大学連携VLBIおよび東アジアVLBI網におけるC-X帯、K帯フロントエンドの開発               
    木村公洋; 長谷川豊; 阿部安宏; 小川英夫; 大西利和; 氏原秀樹(NICT; Soon Kang Lou; 杉山孝一郎; 米倉覚則; 蜂須賀一也; 藤沢健太; 松本尚子; 本間希樹; 小林秀行; 川口則幸
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 東アジアVLBI観測網構築に向けた試験観測の状況               
    萩原喜昭; 小林秀行; 小山友明; 藤沢健太; 新沼浩太郎; 米倉覚則; 他EAVN 試験観測チー
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • EAVNによる 6.7 GHzメタノール・メーザーの固有運動計測プロジェクト               
    杉山孝一郎; 藤沢健太; 蜂須賀一也; 元木業人; 平野大樹; 林京之介; 新沼浩太郎; 米倉覚則; 百瀬宗武; 齋藤悠; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 松本尚子; 村田泰宏; 土居明広; Shen, Zhiqiang; 小川英夫
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 茨城 32-m 鏡による 6.7 GHz メタノールメーザー源の単一鏡強度モニター               
    米倉 覚則; 杉山 孝一郎; 齋藤 悠; 石井 翔太; 百瀬 宗武; 平本 信善; 元木 業人; 藤沢 健太
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • EAVNによる6.7GHzメタノール・メーザーのVLBIサーベイ VIII               
    松本尚子; 藤沢健太; 蜂須賀一也; 元木業人; 平野大輝; 林京之介; 新沼浩太郎; 杉山孝一郎; 米倉覚則; 齋藤悠; 茨; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 村田泰宏; 土居明広; 小川英夫
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 大質量原始星ジェットに付随する青方偏移卓越メーザー観測プロジェクト               
    元木業人; 新沼浩太郎; 蜂須賀一也; 藤沢健太; 徂徠和夫; 杉山孝一郎; 米倉覚則; 本間希樹; Andrew J. Walsh; Curtin Uni
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 大学VLBI連携を用いた近傍銀河AGNのアンモニア吸収線観測計画               
    宮本祐介; 中井直正; 久野成夫; 瀬田益道; Salak Dragan; 他; 山内彩; 米倉覚則
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • EAVNによる6.7 GHz メタノール・メーザーのVLBIサーベイ IX:ペア形状天体の内部固有運動               
    蜂須賀一也; 藤沢健太; 元木業人; 平野大樹; 林京之介; 杉山孝一郎; 米倉覚則; 澤田-佐藤聡子; 松本尚子; 村田泰宏(ISAS; JAXA)ほか
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • Sgr A* at 22 GHz around the G2 peri-center passing with Japanese VLBI Network               
    Y. Asaki; M. Tsuboi (ISAS/JAXA; Y. Yonekura; Y. Miyamoto; aki; H. Kaneko; M. Seta; N. Nakai; v. of Tsukuba; O. Kameya; M. Miyoshi (NAOJ; H. Takaba; K. Wakamatsu; Gifu Uni; Y. Fukuzaki (GSI; K. Uehara; iv. of Tokyo; M. Sekido (NICT; T. Oka; S. Takekawa; Keio; A. Takumi; The Open; University of Japa; S. Horiuchi; CSIRO; R. Dodson; v. of; W
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 大学間連携によるAGNジェットの多波長観測               
    伊藤亮介; 深沢泰司; 田中康之; 秋田谷洋; 川端弘治; 吉田道利; 植村誠; 森谷友由希; 上野一誠; 高木勝俊; 渡辺誠; 米倉覚則; 齋藤悠; 茨; 斉藤嘉彦; 大朝由美子; 永山貴宏; 笹田真人; 大島誠人; 新井彰; 高木悠平; 高橋隼; 奥村真一郎; 浦川聖太郎; スペースガード協会; 黒田大介; 磯貝瑞希; 泉浦秀行; 永山貴宏; 藤沢健太; 新沼浩太郎; ほか光; 赤外線大学間連携観測チーム
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会, [Invited]
  • 臼田宇宙空間観測所64m電波望遠鏡による中性水素原子ガス21cm線の観測               
    中西裕之; 齊田智恵; 村田泰宏; 坪井昌人; 米倉覚則; 土橋一仁; ほか臼; 鏡ライン観測WGメンバー
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 野辺山45m電波望遠鏡搭載45 GHz受信機(Z45)の試験観測               
    落合 哲; 土橋 一仁; 下井倉 ともみ; 米谷 夏樹; 米倉 覚則; 百瀬 宗武; 佐藤 雄貴; 中島 拓; 水野 いづみ; 国立天文台; 岡田 望; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 小川 英夫; 中村 文隆; 亀野 誠二; 新永 浩子; 久野 成夫; 高野 秀路; 伊王野 大介; 川辺 良平; 楠野 こず枝; 谷口 琴美
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 野辺山45m鏡搭載Z45受信機によるペルセウス座領域のCCSマッピング               
    米谷 夏樹; 土橋 一仁; 下井倉 ともみ; 落合 哲; 米倉 覚則; 百瀬 宗武; 佐藤 雄貴; 中島 拓; 水野 いづみ; 国立天文台; 岡田 望; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 小川 英夫; 中村 文隆; 亀野 誠二; 新永 浩子; 久野 成夫; 高野 秀路; 伊王野 大介; 川辺 良平; 楠野 こず枝; 谷口 琴美
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • JVLA/ATCAによる大質量原始星ジェット天体に付随する降着円盤候補の検出               
    元木業人; 新沼浩太郎; 蜂須賀一也; 藤沢健太; 徂徠和夫; 杉山孝一郎; 米倉覚則; 本間希樹; 廣田朋也; Andrew J. Walsh; Curtin; Uni
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • VERAとALMAを用いたオリオンKL水メーザーバースト天体の観測               
    廣田朋也; 本間希樹; 黒野泰隆; 金美京; 韓国天文研究院; 坪井昌人; 藤沢健太; 今井裕; 鹿児島; 米倉覚則
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • メタノールメーザーの強度変動を伴う天体MonR2-IRS3の近赤外線モニター観測               
    内山瑞穂; 宮田隆志; 酒向重行; 上塚貴史; 細川隆史; 山下智志; 面高俊宏; 宇井崇紘; 秋田谷洋; 森谷友由希; 川端弘治; 杉山孝一郎; 米倉覚則; 齋藤悠; 石井翔太; 百瀬宗武; 元木業人; 稲吉恒平; Columbia U; 田中圭(Univ. of Florid
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • No Microwave Flare of Sgr A* around the G2 Periastron Passing               
    M. Tsuboi; Y. Asaki (ISAS/JAXA; Y. Yonekura; Y. Miyamoto(Ibaraki Univ; H. Kaneko; M. Seta; N. Nakai; v. of Tsukuba; O. Kameya; M. Miyoshi (NAOJ; H. Takaba; K. Wakamatsu; Gifu Uni; Y. Fukuzaki (GSI; K. Uehara; iv. of Tokyo; M. Sekido (NI
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • VERA搭載用86 GHz帯セプタム型円偏波ポーラライザーの開発               
    Soon Kang Lou; 米倉 覚則; 百瀬 宗武; 長谷川 豊; 木村 公洋; 小川 英夫; 本間 希樹
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 野辺山45m鏡における40 GHz帯偏波計測システム               
    水野 いづみ; 国立天文台; 亀野 誠二; 中村 文隆; 楠野 こずえ; 新永 浩子; 高野 秀路; 土橋 一仁; 下井倉 ともみ; 落合 哲; 米谷 夏樹; 米倉 覚則; 小川 英夫; 岡田 望; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 谷口 琴美; 中島 拓; 久野 成夫; 受信機開発チー
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 野辺山40 GHz帯偏波システムによるゼーマン効果計測性能評価               
    亀野誠二; 水野いづみ; 中村文隆; 新永浩子; 高野秀路; 楠野こずえ; 土橋一仁; 下井倉ともみ; 落合哲; 米倉覚則; 小川英夫; 岡田望; 徳田一起; 長谷川豊; 阿部安宏; 木村公洋; 谷口琴美; 中島拓; 久野成夫; 受信機開発チー
    日本天文学会2014年秋季年会, Sep. 2014, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (10)               
    米倉 覚則; 齋藤 悠; 森 智彦; Soon Kang Lo; 石井 翔太; 佐藤 雄貴; 古川 尚子; 宮本祐介; 百瀬 宗武; 吉田龍生; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 小林 秀行; 川口 則幸; 他大学間連携; VLBI group
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • VERA搭載用86GHz受信機の開発               
    岡田 望; 木村 公洋; 田中 奏太; 阿部 安宏; 村岡 和幸; 前澤 裕之; 大西利和; 小川 英夫; 本間 希樹; 澤田-佐藤; 聡; Soon KangLou; 百瀬 宗武; 米倉 覚則
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • 単一鏡電波観測における偏波計測手法               
    水野 いづみ; 国立天文台; 亀野 誠二; 中村 文隆; 久野 成夫; 高野 秀路; 新永 浩子; 土橋 一仁; 下井倉 ともみ; 落合 哲; 米倉 覚則; 田中 智博; 小川 英夫; 岡田 望; 高津 湊; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 中島 拓; 受信機開発チー
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • 短基線VLBIによるSagittarius A* の2014年事象のモニター観測               
    坪井昌人; 朝木義晴(ISA; 米倉覚則; 金子紘之; 高羽 浩; 亀谷 收; 関戸 衛(NICT; ほかSgrA$^\ast$毎日モニタグループ一同
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • EAVNによる 6.7 GHzメタノール・メーザーのVLBIサーベイ VII:楕円形状天体の固有運動 まとめ               
    杉山孝一郎; 藤沢健太; 元木業人; 新沼浩太郎; 平野大樹; 蜂須賀一也; Shen, Zhiqiang; 米倉覚則; 百瀬宗武; 古川尚子; 齋藤悠; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 松本尚子; 村田泰宏; 土居明広; 小川英夫
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • 6.7 GHzメタノール・メーザーの周期強度変動探査 II:100日周期天体               
    杉山孝一郎; 元木業人; 藤沢健太; 齋藤悠; 石井翔太; 古川尚子; 米倉覚則; 百瀬宗武; 本間希樹; 稲吉恒平; 田中圭; 細川隆史; 内山瑞穂; 蜂須賀一也
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • SMAによる"face-on"大質量原始星候補天体G353の高分解能観測               
    元木業人; 松下聡樹; ASIAA)、Andrew J. Walsh; Curtin University; 藤沢健太; 杉山孝一郎; 新沼浩太郎; 徂徠和夫; 本間希樹; 廣田朋也; 米倉覚則; 蜂須賀一也
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • 鹿島局、山口局、茨城局のおけるアイソン彗星の電波観測               
    布施哲治; 藤沢健太; 米倉覚則; 亀崎達矢; 永山匠; 川合栄治; 関戸衛
    日本天文学会2014年春季年会, Mar. 2014, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (9)               
    米倉 覚則; 齋藤 悠; 森 智彦; Soon Kang Lo; 石井 翔太; 佐藤 雄貴; 古川 尚子; 百瀬 宗武; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 面高 俊宏; 小山友明; 河野裕介; 水野翔太; 小林 秀行; 川口 則幸; 他大学間連携; VLBI group
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 86GHz帯円偏波ポーラライザーの開発               
    Soon Kang Lou; 百瀬 宗武; 米倉 覚則; 長谷川 豊; 木村 公洋; 小川 英夫; 本間 希樹
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • ソフトウェア偏波分光計PolariSの開発II               
    水野 いづみ; 国立天文台; 亀野 誠二; 中村 文隆; 久野 成夫; 高野 秀路; 新永 浩子; 土橋 一仁; 下井倉 ともみ; 落合 哲; 米倉 覚則; 田中 智博; 小川 英夫; 岡田 望; 高津 湊; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 中島 拓; 受信機開発チー
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 野辺山 45 m 電波望遠鏡 45 GHz 帯受信機 (Z45) のアンテナ搭載試験               
    米倉 覚則; 土橋 一仁; 下井倉 ともみ; 落合 哲; 中島 拓; 水野 いづみ; 国立天文台; 田中 智博; 岡田 望; 高津 湊; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 小川 英夫; 中村 文隆; 亀野 誠二; 新永 浩子; 久野 成夫; 高野 秀路; 伊王野 大介; 川辺 良平
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 野辺山45 m電波望遠鏡搭載45 GHz受信機(Z45)の開発               
    岡田 望; 高津 湊; 田中 智博; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 村岡 和幸; 前澤 裕之; 大西 利和; 小川 英夫; 中村 文隆; 亀野 誠二; 新永 浩子; 久野 成夫; 高野 秀路; 伊王野 大介; 川辺 良平; 水野 いづみ; 島; 立天文台; 中島 拓; 米倉 覚則; 落合 哲; 下井倉 ともみ; 土橋 一仁
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 短基線VLBIによるSagittarius A*の2013年事象の観測 II:最初の4ヶ月の結果               
    坪井昌人; 朝木義晴(ISA; 米倉覚則; 金子紘之; 高羽 浩; 亀谷 收; 関戸 衛(NICT; ほかSgrA; 毎日モニタグループ一同
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 野辺山45m電波望遠鏡搭載45GHz受信機(Z45)の試験観測               
    落合 哲; 土橋 一仁; 下井倉 ともみ; 米倉 覚則; 中島 拓; 水 野いづみ; 国立天文台; 田中 智博; 岡田 望; 高津 湊; 徳田 一起; 長谷川 豊; 阿部 安宏; 木村 公洋; 小川 英夫; 中村 文隆; 亀野 誠二; 新永 浩子; 久野 成夫; 高野 秀路; 伊 王野; 大; 川辺 良平
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 野辺山45m鏡45GHz帯新受信機Z45を用いたCCSマッピング観測               
    中村文隆; 小川英夫; 土橋一仁; 米倉覚則; 亀野誠二; 水野いづみ; 下井倉ともみ; 西谷洋之; 中島拓; 落合哲; 田中智博; 木村公洋; 高津湊; 岡田望; 徳田一起; 高野秀路; 伊王野大介; 新永浩子; 久野成夫; 川辺良平; 大西利和; 百瀬宗武; 松本倫明; 山本智; 前澤裕之; 廣田朋也; ーム
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 6.7 GHzメタノール・メーザーの周期強度変動探査 I:プロジェクト概要               
    杉山孝一郎; 元木業人; 藤沢健太; 齋藤悠; 古川尚子; 米倉覚則; 百瀬宗武; 本間希樹; 稲吉恒平; 田中圭; 細川隆史
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • EAVNによる 6.7 GHzメタノール・メーザーのVLBIサーベイ VI:2010-2012年間における内部固有運動議論 その2               
    杉山孝一郎; 藤沢健太; 元木業人; 新沼浩太郎; 平野大樹; 山口; 蜂須賀一也; Shen, Zhiqiang; 天文; 米倉覚則; 百瀬宗武; 古川尚子; 齋藤悠; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 松本尚子; 村田泰宏; 土居明広; 小川英夫
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 大質量原始星G353に付随するコンパクトジェットと光学的に厚いエンベロープの検出               
    元木業人; Andrew J. Walsh; Curtin University; 藤沢健太; 杉山孝一郎; 新沼浩太郎; 徂徠和夫; 本間希樹; 廣田朋也; 米倉覚則
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • JVNによる恒星からの非熱的電波の観測               
    廣田朋也; 小山友明; 河野裕介; 水野翔太; 米倉覚則; 新沼浩太郎; 藤沢健太; 村田泰宏; 他VERA; JVNグループ
    日本天文学会2013年秋季年会, Sep. 2013, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (8)               
    米倉 覚則; 齋藤 悠; 斎藤 貴文; 森 智彦; Soon Kang Lo; 百瀬 宗武; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小山友明; 河野裕介; 水野翔太; 小林 秀行; 川口 則幸; 他大学間連携; VLBI group
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • 茨城 32 m 鏡搭載用 22 GHz 帯冷却受信機の開発               
    森智彦; Soon Kang Lou; 齋藤貴文; 齋藤悠; 米倉覚則; 百瀬宗武; 横沢正芳; 長谷川豊; 木村公洋; 小川英夫
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • ブレーザー天体 CTA 102の多波長光度・色・偏光短期変動観測               
    伊藤亮介; 深沢泰司; 田中康之; 秋田谷洋; 川端弘治; 吉田道利; 植村誠; 森谷友由希; 上野一誠; 高木勝俊; 渡辺誠; 米倉覚則; 齋藤悠; 茨; 斉藤嘉彦; 永山貴宏; 笹田真人; 大島誠人; 磯貝瑞希; 新井彰; 高木悠平; 高橋隼; 奥村真一郎; 浦川聖太郎; スペースガード協会; 黒田大介; 泉浦秀行; 宮ノ下亮; ほか光; 赤外線大学間連携観測チーム
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • 電波強度の強い狭輝線1型セイファート銀河RX\,J1633+4718のすざく、かなた、VLBIによる多波長準同時観測(2)               
    高橋宏明; 林田清; 穴吹直久; 秋田谷洋; 伊藤亮介; 藤沢健太; 新沼浩太郎; 杉山孝一郎; 米倉覚則; 土居明広
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • EAVN による 6.7GHz メタノール・メーザーの VLBI サーベイ IV ~G8.683-0.368 における内部固有運動の計測~               
    齋藤貴文; 米倉覚則; 百瀬宗武; 齋藤悠; 杉山孝一郎; 元木業人; 藤沢健太; 蜂須賀一也
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • EAVN による 6.7GHz メタノール・メーザーの VLBI サーベイ III:2010-2012年間における内部固有運動議論 その1               
    杉山孝一郎; 藤沢健太; 元木業人; 新沼浩太郎; 蜂須賀一也; Shen, Zhiqiang; 天; 米倉覚則; 百瀬宗武; 齋藤悠; 齋藤貴文; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 村田泰宏; 土居明広; 小川英夫
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • 短基線 VLBI による Sagittarius A∗ の 2013 年事象の観測               
    坪井昌人; 朝木義晴; IS; 米倉覚則; 宮本祐介; 高羽浩; 岐阜大; 亀谷 收; 国; ほか SgrA∗; 毎日モニタグループ一同
    日本天文学会2013年春季年会, Mar. 2013, 日本天文学会
  • The VLBI Imaging Survey of the 6.7 GHz Methanol Masers using the JVN/EAVN               
    K. Sugiyama; K. Fujisawa; K. Hachisuka; Y. Yonekura; K. Motogi; M. Honma; T. Hirota; S. Sawada-Satoh; K. Niinuma; Y. Murata; A. Doi; H. Ogawa; and Z.-Q. Shen
    New Trends in Radio Astronomy in the ALMA Era, Dec. 2012
  • New detection of an extremely blue-shift dominated jet in G353.273+0.641: A possible disk-jet system on 100 au scale               
    K. Motogi; K. Fujisawa; K. Sugiyama; K. Niinuma; K. Sorai; M. Honma; T. Hirota; Y. Yonekura; K. Hachisuka; A. Walsh
    New Trends in Radio Astronomy in the ALMA Era, Dec. 2012
  • High-resolution observations of centimeter/(sub)millimeter H2O masers in Orion KL with VERA and ALMA               
    T. Hirota; M. Tsuboi; K. Fujisawa; M. Honma; N. Kawaguchi; M. K. Kim; H. Kobayashi; Y. Kurono; H. Imai; T. Omodaka; K. M. Shibata; T. Shimoikura; Y. Yonekura
    New Trends in Radio Astronomy in the ALMA Era, Dec. 2012
  • 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
    New Trends in Radio Astronomy in the ALMA Era, Dec. 2012
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (7)               
    米倉 覚則; 齋藤 悠; 斎藤 貴文; 森 智彦; Soon Kang Lo; 百瀬 宗武; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; 他大学間連携; VLBI group
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • センチ波 (8.4 GHz) で見た金環日食               
    米倉 覚則; 齋藤 悠; 百瀬 宗武; 横沢 正芳; 辻 龍介; 吉田 龍生; 野澤 恵
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • 茨城 32 m 電波望遠鏡のアンテナ性能評価               
    齋藤悠; 森智彦; Soon Kang Lo; 米倉覚則; 百瀬宗武; 横沢正芳
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • 短基線VLBIによるSagittarius A*の毎日観測:2013年事象に向けて               
    坪井昌人; 朝木義晴(ISA; 米倉覚則; 宮本祐介; 高羽浩; 岐阜大)ほかSgrA; 毎日モニタグループ一同
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • 電波強度の強い狭輝線 1 型セイファート銀河 RX J1633+4718 のすざく、 かなた、VLBI による多波長準同時観測               
    高橋宏明; 林田清; 穴吹直久; 秋田谷洋; 伊藤亮介; 藤沢健太; 新沼浩 太郎; 杉山孝一郎; 米倉覚則; 土居明広
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • ATCAを用いた6.7GHzメタノール・メーザーのイメージングサーベイ               
    杉山孝一郎; 藤沢健太; 元木業人; 蜂須賀一也; 天文台; 、Richard Dodson; Maria Rioja (ICRAR; 米倉覚則; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 立天文; 村田泰宏; 土居明広; 小川英夫; Simon Ellingsen (UTAS
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • ALMA cycle 0 におけるオリオン KL 領域の観測               
    廣田朋也; 本間希樹; 金美京; 黒野泰隆; 坪井昌人; 藤沢健太; 今井裕; 下井倉ともみ; 米倉覚則
    日本天文学会2012年秋季年会, Sep. 2012, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (6)               
    米倉 覚則; 栗橋 潤; 齋藤 悠; 滝沢 美里; 田中 智明; 斎藤 貴文; 百瀬 宗武; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2012年春季年会, Mar. 2012, 日本天文学会
  • 茨城 32m 電波望遠鏡の単一鏡分光観測システム開発               
    田中智明; 栗橋潤; 齋藤悠; 滝沢美里; 米倉覚則; 百瀬宗武; 横沢正芳
    日本天文学会2012年春季年会, Mar. 2012, 日本天文学会
  • 茨城 32 m 電波望遠鏡・日立アンテナの指向誤差 (3)               
    齋藤悠; 栗橋潤; 滝沢美里; 田中智明; 米倉覚則; 百瀬宗武; 横沢正芳
    日本天文学会2012年春季年会, Mar. 2012, 日本天文学会
  • JVN / VERAを用いた大質量原始星ジェットのモニター計画               
    元木業人; 徂徠和夫; 藤沢健太; 杉山孝一郎; 本間希樹; 米倉覚則; 蜂須賀一也
    日本天文学会2012年春季年会, Mar. 2012, 日本天文学会
  • EAVNによる6.7GHzメタノール・メーザーのVLBIサーベイ II               
    杉山孝一郎; 藤沢健太; 蜂須賀一也; 米倉覚則; 百瀬宗武; 齋藤悠; 齋藤貴文; 本間希樹; 廣田朋也; 澤田-佐藤聡子; 村田泰宏; 土居明広; 元木業人; 小川英夫
    日本天文学会2012年春季年会, Mar. 2012, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (5)               
    米倉 覚則; 栗橋 潤; 齋藤 悠; 滝沢 美里; 田中 智明; 斎藤 貴文; 百瀬 宗武; 横沢 正芳; 木村 公洋; 西村 淳; 木澤 淳基; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • VERAによるオリオンKL水メーザーバースト天体の観測               
    廣田朋也; 坪井昌人; 本間希樹; 川口則幸; 金美京; 小林秀行; 柴田克典; 藤沢健太; 今井裕; 面高俊宏; 下井倉ともみ; 米倉覚則
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • マイクロクエイザーCyg X-3からの電波-γ線フレア (2011年)               
    小谷太郎; 秋山和徳; 遠藤渉; 河合誠之; 久野成夫; 坪井昌人; 土居明広; 中西康一郎; 中平聡志; 廣田晶彦; 藤沢健太; 宮崎敦史; 山岡和貴; 米倉覚則
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • 茨城32m鏡用ノイズソース法を用いた受信機雑音温度較正システムの開発               
    木村 公洋; 木澤 淳基; 古家野 誠; 前澤 裕之; 大西 利和; 小川 英夫; 滝沢 美里; 栗橋 潤; 齋藤 悠; 田中 智明; 米倉 覚則; 宮村 太基; 藤沢 健太; 川口 則幸; 小林 秀行
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • 茨城 32m 鏡搭載用 6.5-8.8GHz 帯低雑音広帯域受信機システム開発の進捗               
    滝沢美里; 栗橋潤; 齋藤悠; 田中智明; 米倉覚則; 百瀬宗武; 横沢正芳; 木澤淳基; 西村淳; 辻英俊; 阪口翼; 片瀬徹也; 木村公洋; 阿部安宏; 大西利和; 小川英夫; 小林秀行
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • 茨城 32m 電波望遠鏡・日立アンテナの能率測定               
    栗橋潤; 齋藤悠; 滝沢美里; 田中智明; 米倉覚則; 百瀬宗武; 横沢正芳
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • 茨城 32m 電波望遠鏡・日立アンテナの指向誤差 (2)               
    齋藤悠; 栗橋潤; 滝沢美里; 田中智明; 米倉覚則; 百瀬宗武; 横沢正芳
    日本天文学会2011年秋季年会, Sep. 2011, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (4)               
    米倉 覚則; 栗橋 潤; 齋藤 悠; 滝沢 美里; 田中 智明; 百瀬 宗武; 横沢 正芳; 木村 公洋; 西村 淳; 松本 浩平; 木澤 淳基; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2011年春季年会, Mar. 2011, 日本天文学会
  • 茨城32 m鏡搭載用6.5–8.8 GHz帯低雑音広帯域受信機システムの開発               
    滝沢 美里; 栗橋 潤; 齋藤 悠; 田中 智明; 米倉 覚則; 百瀬 宗武; 横沢 正芳; 木澤 淳基; 西村 淳; 松本 浩平; 辻 英俊; 阪口 翼; 片瀬 徹也; 木村 公洋; 阿部 安宏; 小川 英夫; 小林 秀行
    日本天文学会2011年春季年会, Mar. 2011, 日本天文学会
  • 茨城 32m 電波望遠鏡・日立アンテナの指向誤差               
    栗橋潤; 齋藤悠; 滝沢美里; 田中智明; 米倉覚則; 百瀬宗武; 横沢正芳
    日本天文学会2011年春季年会, Mar. 2011, 日本天文学会
  • 茨城・上海を含む東アジア VLBI 観測網によるメタノール・メーザ観測               
    藤沢健太; 杉山孝一郎; 蜂須賀一也; 米倉覚則; 土居明広; 望月奈々子; 澤田佐藤聡子; 元木業人; 小川英夫
    日本天文学会2011年春季年会, Mar. 2011, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況 (3)               
    米倉 覚則; 栗橋 潤; 齋藤 悠; 滝沢 美里; 田中 智明; 百瀬 宗武; 横沢 正芳; 木村 公洋; 西村 淳; 松本 浩平; 木澤 淳基; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2010年秋季年会, Sep. 2010, 日本天文学会
  • 6.7GHzメタノールメーザー、8GHz帯同時受信ポーラライザーの開発(II)               
    松本 浩平; 木村 公洋; 小川 英夫; 大西 利和; 氏原 秀樹; NI; 浅利 一善; 本間 希樹; 小林 秀行; 三谷 友彦; 米倉 覚則
    日本天文学会2010年秋季年会, Sep. 2010, 日本天文学会
  • ASTRO-G衛星搭載8GHz帯受信機の6.7GHz帯までの観測帯域拡張提案               
    小川英夫; 木村公洋; 松本浩平; 氏原秀樹(NIC; 藤沢健太; 米倉覚則; 村田泰宏(ISAS/JAXA
    日本天文学会2010年秋季年会, Sep. 2010, 日本天文学会
  • 高萩/日立32m電波望遠鏡の整備状況(2)               
    米倉 覚則; 百瀬 宗武; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2010年春季年会, Mar. 2010, 日本天文学会
  • 高萩 / 日立 32 m 電波望遠鏡の整備状況               
    米倉 覚則; 百瀬 宗武; 横沢 正芳; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • 1.85 m 電波望遠鏡観測プログラムの開発               
    竹中 敬雅; 辻 英俊; 國實 真人; 西村 淳; 箕輪 昌裕; 小嶋 崇文; 海田 正大; 木村 公洋; 阿部 安宏; 大西 利和; 小川 英夫; 米倉 覚則; 中島 拓; 久野 成夫; 半田 利弘; 秋里 昂; 土橋 一仁
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • 1.85m 電波望遠鏡 FFT 電波分光計システムの開発 (II): Acqiris AC240 のLinux 制御と Socket サーバー化               
    西村 淳; 阪口 翼; 竹中 敬雅; 國實 真人; 箕輪 昌裕; 海田 正大; 木村 公洋; 阿部 安宏; 大西 利和; 小川 英夫; 米倉 覚則; 大橋健次郎; 秋里 昂; 土橋 一仁; 中島 拓; 久野 成夫
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • 1.85 m 電波望遠鏡受信機・中間周波数系の開発               
    箕輪 昌裕; 八嶋 信平; 國實 真人; 西村 淳; 竹中 敬雅; 海田 正大; 木村公洋; 小嶋 崇文; 阿部 安宏; 大西 利和; 小川 英夫; 米倉 覚則; 中島 拓; 久野 成夫
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • 1.85m電波望遠鏡ファーストライト               
    木村 公洋; 海田 正大; 竹中 敬雅; 國實 真人; 箕輪 昌裕; 西村 淳; 松本 浩平; 黒岩 宏一; 小嶋 崇文; 阿部 安宏; 大西 利和; 小川 英夫; 米倉 覚則; 半田 利弘; 秋里 昂; 土橋 一仁; 中島 拓; 久野 成夫
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • 茨城—鹿島波長多重光通信回線の整備と利用計画               
    川口則幸; 河野裕介; 小山友明; 鈴木駿策; 原 哲也; 米倉覚則
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • NANTEN2プロジェクトの進捗               
    奥田 武志; 山本 宏昭; 河村 晶子; 福井 康雄; 前澤 裕之; 水野 亮; 大西 利和; 小川 英夫; 水野 範和; 米倉 覚則; Stutzki; ケルン大; F. Bertoldi; ボン大; B.C. Koo; ソウル国立大; L. Bronfman(チリ大; M. Burton (UNS; 、A. Benz; ETH Zurich; NANTEN2チーム
    日本天文学会2009年秋季年会, Sep. 2009, 日本天文学会
  • 茨城 32 m 電波望遠鏡 (高萩局、日立局) の整備計画               
    米倉 覚則; 百瀬 宗武; 横沢 正芳; 星 慶幸; 小川 英夫; 藤沢 健太; 高羽 浩; 徂徠 和夫; 中井 直正; 亀野 誠二; 小林 秀行; 川口 則幸; ほか大学間連携; VLBI グループ
    日本天文学会2009年春季年会, Mar. 2009, 日本天文学会
  • 茨城 32m 鏡搭載用 6.7GHz 帯冷却受信機の開発               
    西村 淳; 木村 公洋; 松本 浩平; 阿部 安宏; 小川 英夫; 米倉 覚則; 百瀬 宗武; 小林 秀行
    日本天文学会2009年春季年会, Mar. 2009, 日本天文学会
  • 1.85 m 電波望遠鏡のビーム伝送系の評価               
    國實 真人; 箕輪 昌裕; 竹中 敬雅; 栗本 裕厳; 海田 正大; 木村 公洋; 小嶋 崇文; 阿部 安宏; 小川 英夫; 米倉 覚則; 中島 拓; 久野 成夫; 半田 利弘; 秋里 昴; 土橋 一仁
    日本天文学会2009年春季年会, Mar. 2009, 日本天文学会
  • 4K GM冷凍機の温度振動低減法に関する開発               
    箕輪 昌裕; 國實 真人; 栗本 裕厳; 海田 正大; 木村 公洋; 小嶋 崇文; 阿部 安宏; 小川 英夫; 米倉 覚則; 中島 拓; 角田 泰啓; 西岡 孝
    日本天文学会2009年春季年会, Mar. 2009, 日本天文学会
  • NANTEN2:サブミリ波観測の進捗状況               
    山本 宏昭; 大西 利和; 福井 康雄; 水野 亮; 名大ST; 水野 範和(NA; 小川 英夫; 米倉覚則; J.Stutzki; ケルン大; F.Bertoldi (ボン大; B.C.Koo; ソウル国立大; L.Bronfman(チリ大; M.Burton (UNS; A.Benz (ETH Zurich; NANTEN2 consortium
    日本天文学会2009年春季年会, Mar. 2009, 日本天文学会

Courses

  • 2018 - Present
    茨城大学
  • 2018 - Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • Present
    茨城大学
  • 2018 - Mar. 2023
    茨城大学
  • 2018 - Mar. 2023
    茨城大学
  • 2011 - 2016
    茨城大学
  • 2015
    茨城大学
  • 2015
    茨城大学
  • 2015
    茨城大学

Affiliated academic society

  • Aug. 2000, International Astronomical Union
  • Apr. 1991, Astronomical Society of Japan

Research Themes

  • 中性子星の磁気圏物理から迫る Repeating FRB の解明               
    Grant-in-Aid for Scientific Research(B)
    Apr. 2022 - Mar. 2026
  • 大質量星形成時の間欠的質量降着に伴う増光現象アクリーションバーストに関する研究               
    Grant-in-Aid for Scientific Research(B)
    Apr. 2021 - Mar. 2025
  • 国内VLBIネットワーク事業               
    Apr. 2022 - Mar. 2023
  • メタノールメーザー高頻度観測による、大質量星形成時の質量降着率の時間変動の解明               
    新学術領域研究(研究領域提案型)(公募研究)
    Apr. 2021 - Mar. 2023
  • 国内VLBIネットワーク事業               
    Apr. 2021 - Mar. 2022
  • 茨城大学重点研究「宇宙科学教育研究センターを核とした宇宙惑星科学教育研究の新展開」               
    Apr. 2015 - Mar. 2022
  • 国内VLBIネットワーク事業               
    Apr. 2019 - Mar. 2020
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2018 - Mar. 2019
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2017 - Mar. 2018
  • 20-25GHz帯広帯域ダイレクトサンプラーによる高感度VLBI 観測システムの開発               
    Apr. 2016 - Mar. 2017
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2016 - Mar. 2017
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2015 - Mar. 2016
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2014 - Mar. 2015
  • 茨城大学推進研究プロジェクト「宇宙科学教育研究センターを核とした分野横断的宇宙惑星科学教育研究の展開」               
    Apr. 2012 - Mar. 2015
  • 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               
    Grant-in-Aid for Scientific Research(B)
    Apr. 2012 - Mar. 2015
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2013 - Mar. 2014
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2012 - Mar. 2013
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2011 - Mar. 2012
  • 高萩および日立32メートル電波望遠鏡を用いた2素子干渉計実験               
    Apr. 2011 - Mar. 2012
  • 茨城大学推進研究プロジェクト「宇宙科学教育研究センターを核とした分野横断的宇宙惑星科学教育研究の展開」               
    Apr. 2009 - Mar. 2012
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2010 - Mar. 2011
  • 茨城32メートル電波望遠鏡を用いたメタノールメーザーと水メーザーの同時観測システムの構築               
    Apr. 2010 - Mar. 2011
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2009 - Mar. 2010
  • 茨城32メートル電波望遠鏡の単一鏡分光観測システムの開発               
    Apr. 2009 - Mar. 2010
  • 大学間連携VLBI観測事業に係る研究 -先端的天文学研究の推進-               
    Apr. 2008 - Mar. 2009

Social Contribution Activities

  • 第14回公開天文台              
    appearance
    茨城大学, 22 Apr. 2023 - 22 Apr. 2023
  • 第13回公開天文台              
    appearance
    茨城大学, 24 Apr. 2022 - 24 Apr. 2022
  • 図書館土曜アカデミー読売新聞連携講座「茨大が探る宇宙の歴史!電波と隕石のメッセージ」              
    lecturer
    茨城大学, 07 Dec. 2019
  • 第10回公開天文台              
    appearance
    茨城大学, 21 Apr. 2019
  • 第9回公開天文台              
    appearance
    茨城大学, 15 Apr. 2018
  • 第8回公開天文台              
    appearance
    茨城大学, 16 Apr. 2017
  • 第7回公開天文台              
    appearance
    茨城大学, 17 Apr. 2016
  • 第6回公開天文台              
    appearance
    茨城大学, 19 Apr. 2015
  • 第5回公開天文台              
    appearance
    茨城大学, 13 Apr. 2014
  • 第4回公開天文台              
    appearance
    茨城大学, 14 Apr. 2013
  • 第3回公開天文台              
    appearance
    茨城大学, 15 Apr. 2012
  • 公開天文台              
    appearance
    茨城大学, 10 Apr. 2010 - 11 Apr. 2010