Monitoring observation of near-infrared flares from supermassive black hole caused by gas accretion

• Project/Area Number: 25707012
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Astronomy
• Research Institution: Miyagi University of Education (2014-2016); National Astronomical Observatory of Japan (2013)
• Principal Investigator: Nishiyama Shogo 宮城教育大学, 教育学部, 准教授 (20377948)
• Research Collaborator: IWAMATSU Atsushi ; KAWAMATA Ikumi ; ONOZATO Hiroki ; ADACHI Rina ; SEKI Megumi
• Project Period (FY): 2013-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥11,050,000 (Direct Cost: ¥8,500,000、Indirect Cost: ¥2,550,000); Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000); Fiscal Year 2015: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2014: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2013: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
• Keywords: 赤外線天文学 / ブラックホール / 銀河系 / 銀河中心核 / 光赤外線天文学 / 宇宙科学 / 分光

Outline of Final Research Achievements

We have carried out near-infrared monitoring observations of the Galactic supermassive black hole, using the IRSF telescope in South Africa. The closest approach of a gas cloud to the supermassive black hole was in around March/April 2013, and flares from the black hole was expected. However, during our monitoring from 2013 to 2015, no clear flaring was detected. The K-band magnitudes of the black hole are fainter than 12 during the period. Our result is consistent with other monitoring observations in radio and X-ray wavelengths.
Using the same data sets, we have searched for variable stars in the central 7 arcmin region of our Galaxy. We have found new variable star candidates: 10 Mira variable stars, and one Cepheid variable. They are previously unknown variable stars.

Research Products

• [Journal Article] Broad-lined Supernova 2016coi with a Helium Envelope (2017)
  • Author(s): Masayuki Yamanaka et al. (including Nozomu Tominaga)
  • Journal Title: The Astrophysical Journal Volume: 837 Issue: 1 Pages: 1-8
  • DOI: 10.3847/1538-4357/aa5f57
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] V5852 Sgr: an unusual nova possibly associated with the Sagittarius stream (2016)
  • Author(s): E. Aydi, P. Mroz, P. A. Whitelock, S. Mohamed, L. Wyrzykowski, A. Udalski, P. Vaisanen, T. Nagayama, M. Dominik, A. Scholz, H. Onozato, R. E. Williams, S. T. Hodgkin, S. Nishiyama, M. Yamagishi, A. M. S. Smith, T. Ryu, A. Iwamatsu, I. Kawamata
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 461 Issue: 2 Pages: 1529-1538
  • DOI: 10.1093/mnras/stw1396
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spectroscopically identified intermediate age stars at 0.5-3 pc distance from Sagittarius A* (2016)
  • Author(s): S. Nishiyama, R. Schoedel, T. Yoshikawa, T. Nagata, Y. Minowa, M. Tamura
  • Journal Title: Astronomy & Astrophysics Volume: 588 Pages: A49-A49
  • DOI: 10.1051/0004-6361/201322392
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Number density distribution of near-infrared sources on a sub-degree scale in the Galactic center: Comparison with the Fe XXV Kα line at 6.7 keV (2015)
  • Author(s): Yasui, K.; Nishiyama, S.; Yoshikawa, T. et al.（12名中8番目）
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 67 Issue: 6
  • DOI: 10.1093/pasj/psv100
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Wide-field Infrared Polarimetry of the ρ Ophiuchi Cloud Core (2015)
  • Author(s): Kwon, J.; Tamura, M.; Hough, J. H. et al.（8名中2番目）
  • Journal Title: The Astrophysical Journal Supplement Series Volume: 220 Issue: 1 Pages: 17-33
  • DOI: 10.1088/0067-0049/220/1/17
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] SUBARU and e-Merlin observations of NGC3718. Diaries of an SMBH recoil? (2015)
  • Author(s): K. Markakis, J. Dierkes, A. Eckart, S. Nishiyama, S. Britzen, M. Garcia-Marin, M. Horrobin, T. Muxlow, J. A. Zensus
  • Journal Title: Astronomy and Astrophysics Volume: 印刷中
  • Peer Reviewed
• [Journal Article] Near-infrared Polarimetry and Interstellar Magnetic Fields in the Galactic Center (2015)
  • Author(s): S. Nishiyama, H. Hatano, T. Nagata, M. Tamura
  • Journal Title: Highlights of Astronomy Volume: 16 Issue: H16 Pages: 387-387
  • DOI: 10.1017/s1743921314011569
• [Journal Article] Kinematics of Classical Cepheids in the Nuclear Stellar Disk (2015)
  • Author(s): N. Matsunaga, K. Fukue, R. Yamamoto, N. Kobayashi, L. Inno, K. Genovali, G. Bono, J. Baba, M. S. Fujii, S. Kondo, Y. Ikeda, S. Hamano, S. Nishiyama, T. Nagata, W. Aoki, T. Tsujimoto
  • Journal Title: The Astrophysical Journal Volume: 799 Issue: 1 Pages: 46-46
  • DOI: 10.1088/0004-637x/799/1/46
  • Peer Reviewed
• [Journal Article] Near-IR Imaging Polarimetry toward a Bright-rimmed Cloud: Magnetic Field in SFO 74 (2015)
  • Author(s): Kusune, Takayoshi; Sugitani, Koji; Miao, Jingqi; Tamura, Motohide; Sato, Yaeko; Kwon, Jungmi; Watanabe, Makoto; Nishiyama, Shogo; Nagayama, Takahiro; Sato, Shuji
  • Journal Title: The Astrophysical Journal Volume: 798 Issue: 1 Pages: 60-75
  • DOI: 10.1088/0004-637x/798/1/60
  • Peer Reviewed / Open Access
• [Journal Article] Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster (2014)
  • Author(s): A. Feldmeier, N. Neumayer, A. Seth, R. Schodel, N. Lutzgendorf, P. T. de Zeeuw, M. Kissler-Patig, S. Nishiyama, C. J. Walcher
  • Journal Title: Astronomy & Astrophysics Volume: 570 Pages: A2-A2
  • DOI: 10.1051/0004-6361/201423777
  • Peer Reviewed
• [Journal Article] The Origin of the Galactic Center Diffuse X-ray Emission Investigated by Near-infrared Observations (2014)
  • Author(s): S.Nishiyama, K. Yasui, T. Nagata, T. Yoshikawa, H. Uchiyama, M. Tamura
  • Journal Title: Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, proceedings of a conference held 19-22 February, 2014 at Ehime University Volume: 1 Pages: 8-11
• [Journal Article] Young Stellar Object Search toward the Boundary of the Central Molecular Zone with Near-infrared Polarimetry (2014)
  • Author(s): Yoshikawa, Tatsuhito; Nishiyama, Shogo; Tamura, Motohide; Kwon, Jungmi; Nagata, Tetsuya
  • Journal Title: The Astrophysical Journal Supplement Volume: 213 Issue: 2 Pages: 22-22
  • DOI: 10.1088/0067-0049/213/2/22
  • Peer Reviewed
• [Journal Article] Multi-band, Multi-epoch Observations of the Transiting Warm Jupiter WASP-80b (2014)
  • Author(s): Akihiko Fukui, Yui Kawashima, Masahiro Ikoma, Norio Narita, Masahiro Onitsuka, Yoshifusa Ita, Hiroki Onozato, Shogo Nishiyama, Haruka Baba, Tsuguru Ryu, Teruyuki Hirano, et al.
  • Journal Title: The Astrophysical Journal Volume: 790 Issue: 2 Pages: 108-108
  • DOI: 10.1088/0004-637x/790/2/108
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Infrared Doppler instrument (IRD) for the Subaru telescope to search for Earth-like planets around nearby M-dwarfs (2014)
  • Author(s): Kotani, Takayuki; Tamura, Motohide; Suto, Hiroshi; Nishikawa, Jun; Sato, Bun'ei; Aoki, Wako; Usuda, Tomonori; Kurokawa, Takashi; Kashiwagi, Ken; Nishiyama, Shogo; Ikeda, Yuji;…; Kudo, Tomoyuki; Kusakabe, Nobuhiko;…; Hori, Yasunori; Omiya, Masashi;…; Harakawa, Hiroki;…; Hirano, Teruyuki; Kuzuhara, Masayuki et al.
  • Journal Title: Proceedings of the SPIE 2014 Volume: 9147 Pages: 914714-914714
  • DOI: 10.1117/12.2055075
  • Peer Reviewed
• [Journal Article] Surface Brightness Profile of the Milky Way's Nuclear Star Cluster (2014)
  • Author(s): R. Schodel, A. Feldmeier, D. Kunneriath, S. Stolovy, N. Neumayer, P. Amaro-Seoane, S. Nishiyama
  • Journal Title: Astronomy & Astrophysics Volume: 566 Pages: A47-A47
  • DOI: 10.1051/0004-6361/201423481
  • Peer Reviewed
• [Journal Article] The origin of the Galactic center diffuse X-ray emission investigated by near-infrared imaging and polarimetric observations (2014)
  • Author(s): S. Nishiyama, K. Yasui, T. Nagata, T. Yoshikawa, H. Uchiyama, M. Tamura
  • Journal Title: Proceedings of the International Astronomical Union Volume: 303 Issue: S303 Pages: 449-453
  • DOI: 10.1017/s1743921314001112
• [Journal Article] The Milky Way nuclear star cluster beyond 1 pc (2014)
  • Author(s): A. Feldmeier, N. Neumayer, A. Seth, P. T. de Zeeuw, R. Schodel, N. Lutzgendorf, M. Kissler-Patig, S. Nishiyama, C. J. Walcher
  • Journal Title: Proceedings of the International Astronomical Union Volume: 303 Issue: S303 Pages: 223-227
  • DOI: 10.1017/s1743921314000611
• [Journal Article] The Origin of the Galactic Center Diffuse X-ray Emission Investigated by Near-infrared Imaging and Polarimetric Observations (2014)
  • Author(s): Shogo Nishiyama, Kazuki Yasui, Tetsuya Nagata, et al.
  • Journal Title: Proceedings of IAU Symposium No. 303: The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus Volume: 未定
• [Journal Article] Surface Brightness Profile of the Milky Way's Nuclear Star Cluster (2014)
  • Author(s): R. Schodel, A. Fledmeier, D. Kunneriath, S. Stolovy, N. Neumayer, P. Amaro-Seoane, S. Nishiyama
  • Journal Title: Astronomy and Astrophysics Volume: 未定
  • Peer Reviewed
• [Journal Article] Magnetically Confined Interstellar Hot Plasma in the Nuclear Bulge of Our Galaxy (2013)
  • Author(s): Nishiyama, S., Yasui, K., Nagata, T., Yoshikawa, T., Uchiyama , H., Schödel, R., Hatano, H., Sato, S., Sugitani, K., Suenaga, T., Kwon, J., Tamura, M.
  • Journal Title: The Astrophysical Journal Volume: 769 Issue: 2 Pages: L28-L28
  • DOI: 10.1088/2041-8205/769/2/l28
  • Peer Reviewed
• [Journal Article] The Efficiency and Wavelength Dependence of Near-infrared Interstellar Polarization toward the Galactic Center (2013)
  • Author(s): Hirofumi Hatano, Shogo Nishiyama, Mikio Kurita, et al.
  • Journal Title: The Astronomical Journal Volume: 145 Issue: 4 Pages: 105-105
  • DOI: 10.1088/0004-6256/145/4/105
  • Peer Reviewed
• [Journal Article] IRSF SIRIUS JHKs Simultaneous Transit Photometry of GJ 1214b (2013)
  • Author(s): Narita, N., Nagayama, T., Suenaga, T., Fukui, A., Ikoma, M., Nakajima, Y., Nishiyama, S., Tamura, M.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 65 Issue: 2 Pages: 27-27
  • DOI: 10.1093/pasj/65.2.27
  • Peer Reviewed
• [Journal Article] Intrinsically Polarized Stars and Implication for Star Formation in the Central Parsec of Our Galaxy (2013)
  • Author(s): Tatsuhito Yoshikawa, et al.
  • Journal Title: The Astrophysical Journal Volume: 778 Issue: 2 Pages: 92-101
  • DOI: 10.1088/0004-637x/778/2/92
  • Peer Reviewed
• [Presentation] The universality of the interstellar extinction law in our Galaxy (2017)
  • Author(s): Shogo Nishiyama
  • Organizer: Workshop on Studies on variable stars and extinction law in the Milky Way and nearby galaxies
  • Place of Presentation: 東京大学本郷キャンパス, 東京都文京区
  • Year and Date: 2017-03-27
  • Int'l Joint Research
• [Presentation] セファイドを用いた銀河面偏光観測 (2017)
  • Author(s): 善光哲哉、栗田光樹夫、木野勝、長友竣、長田哲也、松永典之、西山 正吾、中島康
  • Organizer: 日本天文学会春季年会
  • Place of Presentation: 九州大学, 福岡県福岡市
  • Year and Date: 2017-03-15
• [Presentation] 銀河系バルジ領域における拡散X線強度と近赤外星数面密度の空間分布比較 (2017)
  • Author(s): 長友竣、長田哲也、栗田光樹夫、木野勝、善光哲哉、鶴剛、山内茂 雄、信川久実子、信川正順、西山正吾
  • Organizer: 日本天文学会春季年会
  • Place of Presentation: 九州大学, 福岡県福岡市
  • Year and Date: 2017-03-15
• [Presentation] Near-infrared Polarimetric Survey of the Central Region of Our Galaxy (2017)
  • Author(s): Shogo Nishiyama
  • Organizer: 2nd CORE-U Conference: Cosmic Polarimetry from Micro to Macro Scales
  • Place of Presentation: 広島大学 東広島キャンパス, 広島県東広島市
  • Year and Date: 2017-02-17
  • Int'l Joint Research / Invited
• [Presentation] Wolf-Rayet 星の食連星探査 (2017)
  • Author(s): 小野里宏樹
  • Organizer: 理学・生命科学 2研究科合同シンポジウム2017
  • Place of Presentation: 東北大学 青葉山キャンパス, 宮城県仙台市
• [Presentation] IRSF による Wolf-Rayet 星の食連星探査 (2017)
  • Author(s): 小野里宏樹
  • Organizer: 2016年度IRSF勉強会
  • Place of Presentation: 名古屋大学, 愛知県名古屋市
• [Presentation] 銀河系中心領域に存在するyoung, intermediate-age stars の起源の探査 (2016)
  • Author(s): 岩松篤史、板由房、西山正吾
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 愛媛大学, 愛媛県松山市
  • Year and Date: 2016-09-14
• [Presentation] 赤外線暗黒星雲 “ネッシー” 星雲の近赤外線偏光観測 (2016)
  • Author(s): 杉谷光司、楠根貴成、中村文隆、西山正吾、SIRPOL チーム
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 愛媛大学, 愛媛県松山市
  • Year and Date: 2016-09-14
• [Presentation] Astrometry and Narrow-band Imaging of the Galactic Center with ULTIMATE-Subaru (2016)
  • Author(s): Shogo Nishiyama
  • Organizer: ULTIMATE-Subaru Science Workshop 2016
  • Place of Presentation: 国立天文台三鷹キャンパス, 東京都三鷹市
  • Year and Date: 2016-06-16
  • Int'l Joint Research / Invited
• [Presentation] Interstellar Extinction Laws from Optical to Infrared Wavelengths in the Galaxy (2016)
  • Author(s): Shogo Nishiyama
  • Organizer: Astronomical Distance Determination in the Space Age
  • Place of Presentation: International Space Science Institute Beijing, China
  • Year and Date: 2016-05-23
  • Int'l Joint Research / Invited
• [Presentation] IRSFによるSgr A*の近赤外線モニター観測 (2016)
  • Author(s): 西山正吾、川俣育幹
  • Organizer: 第31回ブラックホール地平面勉強会
  • Place of Presentation: 宇宙科学研究所相模原キャンパス(神奈川県相模原市)
  • Year and Date: 2016-01-23
• [Presentation] Sgr A*近傍の星の観測とSMBH (2016)
  • Author(s): 西山正吾
  • Organizer: ブラックホール地平面勉強会
  • Place of Presentation: 宇宙科学研究所相模原キャンパス, 神奈川県相模原市
• [Presentation] 銀河系中心における拡散X線放射と星数密度分布との違いについて (2015)
  • Author(s): 西山正吾、長田哲也、長友竣、田村元秀
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 甲南大学(兵庫県神戸市)
  • Year and Date: 2015-09-09
• [Presentation] 鉄輝線放射率から探る銀河系拡散X線放射の放射源 (2015)
  • Author(s): 長友竣、長田哲也、西山正吾、永山貴宏
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 甲南大学(兵庫県神戸市)
  • Year and Date: 2015-09-09
• [Presentation] G2騒動は終わったか (2015)
  • Author(s): 西山正吾
  • Organizer: 第28回ブラックホール地平面勉強会
  • Place of Presentation: 宇宙科学研究所相模原キャンパス(神奈川県相模原市)
  • Year and Date: 2015-08-10
• [Presentation] 近赤外線観測で探る銀河系中心領域の拡散X線放射の起源 (2015)
  • Author(s): 西山正吾、長友竣、安井一樹、長田哲也、義川達人、田村元秀、内山秀樹
  • Organizer: 天の川銀河研究会 2015
  • Place of Presentation: 東京大学(東京都文京区)
  • Year and Date: 2015-03-23 – 2015-03-24
• [Presentation] 近赤外線による銀河系中心ブラックホール近傍の観測 (2015)
  • Author(s): 西山正吾
  • Organizer: 第８回ブラックホール磁気圏研究会
  • Place of Presentation: 広島大学(広島県東広島市)
  • Year and Date: 2015-03-02 – 2015-03-04
  • Invited
• [Presentation] 銀河中心の赤外線観測、Sgr A*周りの恒星、ガス雲G2の運動 (2014)
  • Author(s): 西山正吾
  • Organizer: 長野ブラックホール天文教育研究会
  • Place of Presentation: 二澤旅館(長野県長野市)
  • Year and Date: 2014-11-15 – 2014-11-16
• [Presentation] 星の偏光観測による銀河系磁場構造の測定 (2014)
  • Author(s): 西山正吾
  • Organizer: 「宇宙磁場」2014
  • Place of Presentation: 国立天文台(東京都三鷹市)
  • Year and Date: 2014-11-13 – 2014-11-14
  • Invited
• [Presentation] 超大質量ブラックホールSgr A*のスピン測定を目指して (2014)
  • Author(s): 西山正吾、田村元秀、濱野哲史、義川達人、長田哲也、高橋真聡、斉田浩見、孝森洋介
  • Organizer: 「超巨大ブラックホール研究推進連絡会」第２回ワークショップ
  • Place of Presentation: 筑波大学(茨城県つくば市)
  • Year and Date: 2014-11-03 – 2014-11-04
• [Presentation] SMBHを周回する星の視線速度モニター計画 (2014)
  • Author(s): 西山正吾、田村元秀、濱野哲史、義川達人、長田哲也、高橋真聡、斉田浩見、孝森洋介
  • Organizer: 第２４回ブラックホール地平面勉強会」研究会
  • Place of Presentation: 湯田温泉ビジネスホテル喜良久(山口県山口市)
  • Year and Date: 2014-10-04 – 2014-10-05
• [Presentation] 銀河系の中心で起きる不思議な現象 (2014)
  • Author(s): 西山正吾
  • Organizer: 日本物理教育学会東北支部総会
  • Place of Presentation: 宮城教育大学(宮城県仙台市)
  • Year and Date: 2014-06-28
  • Invited
• [Presentation] 銀河系中心だからこそできるブラックホール近傍のサイエンス (2014)
  • Author(s): 西山正吾
  • Organizer: 「活動銀河核ワークショップ ～2020年代への展望～」
  • Place of Presentation: 国立天文台(東京都三鷹市)
  • Year and Date: 2014-04-23 – 2014-04-24
  • Invited
• [Presentation] The Origin of the Galactic Center Diffuse X-ray Emission Investigated by Nearinfrared Observations (2014)
  • Author(s): Shogo Nishiyama
  • Organizer: Suzaku-MAXI 2014, Expanding the Frontiers of the X-ray Universe
  • Place of Presentation: Ehime University, Ehime
• [Presentation] 銀河系Nuclear Star Clusterに広く分布する年齢50-500Myrの星 (2014)
  • Author(s): 西山正吾
  • Organizer: 日本天文学会春期年会
  • Place of Presentation: 国際基督教大学
• [Presentation] 近赤外線観測で探る銀河系中心拡散X線放射の起源 (2013)
  • Author(s): 西山正吾
  • Organizer: 銀河系中心部ワークショップ２０１３
  • Place of Presentation: 名古屋大学
  • Invited
• [Presentation] Observations of the Galactic center with Subaru/GLAO (2013)
  • Author(s): Shogo Nishiyama
  • Organizer: Subaru Ground Layer AO Science Workshop
  • Place of Presentation: Hokkaido University
  • Invited
• [Presentation] 近赤外線観測で探る銀河系中心拡散X線放射の起源 (2013)
  • Author(s): 西山正吾
  • Organizer: 日本天文学会秋季年会
  • Place of Presentation: 東北大学
• [Presentation] The origin of the Galactic center diffuse X-ray emission investigated by near-infrared imaging and polarimetric observations (2013)
  • Author(s): Shogo Nishiyama
  • Organizer: The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus
  • Place of Presentation: La Fonda on the Plaza, Sante Fe, USA
• [Presentation] Probing Space-time Structure near Massive Black Hole with Orbiting Stars (2013)
  • Author(s): Shogo Nishiyama
  • Organizer: Astronomy in the TMT Era
  • Place of Presentation: Fukuracia Tokyo Station, Tokyo
• [Presentation] Large Scale Magnetic Field Configuration in the Galactic Center (2013)
  • Author(s): Shogo Nishiyama
  • Organizer: The Galactic Center Black Hole Laboratory
  • Place of Presentation: Instituto des Astrofisica de Andalusia, Granada, Spain