Exploring dynamic pictures of supermassive black holes with movie reconstruction from event-horizion-scale observations

• Project/Area Number: 19KK0081
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 16:Astronomy and related fields
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: 本間 希樹 国立天文台, 水沢VLBI観測所, 教授 (20332166)
• Co-Investigator(Kenkyū-buntansha): 笹田 真人 東京科学大学, 科学技術創成研究院, 特任助教 (10725352) ; 池田 思朗 統計数理研究所, 先端データサイエンス研究系, 教授 (30336101)
• Project Period (FY): 2019-10-07 – 2026-03-31
• Project Status: Granted (Fiscal Year 2024)
• Budget Amount: ¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000); Fiscal Year 2024: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2023: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2022: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2021: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2020: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2019: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 巨大ブラックホール / 超長基線干渉計 / 動画解析 / 超長基線電波干渉計 / 超長電波基線電波干渉計

Outline of Research at the Start

人類史上初めて巨大ブラックホールの影を静止画で捉えたEHT（Event Horizon Telescope）による観測的研究を発展させ、さらなる観測データの蓄積と画像解析方法の向上により画像に時間軸を導入した動画撮影を目指す。それによって、ブラックホール周辺で起こるガスの運動やジェットの放出現象などさまざまな物理現象の時間変動を捉え、ブラックホールおよびその周辺の動的な姿を明らかにする。

Outline of Annual Research Achievements

今年度もブラックホール動画解析の最重要天体であるM87といて座A＊について、VLBI観測に基づく研究を進めた。M87については、昨年度Event Horizon Telescope(EHT)で撮影した2018年の画像（動画の２コマ目に相当）に関して、理論シミュレーションによる解釈を実施し論文として成果を出版した。また2018年のM87の観測キャンペーンで得らえた多波長観測データについても論文化を進め、キャンペーン期間中のフレア検出に成功したことを報告した。これら結果は、ブラックホールの動画化による時間変動の研究を改めて示すものとなった。いて座A*については、VERAの43GHz観測によるモニター観測の結果がまとまり、劇的な強度変動は検出されなかった一方で、人類史上初の年周視差測定に成功した。測定されたいて座A*の距離は、いて座A*周辺ので恒星の運動から求められている値と合致した。
これらの観測的研究のとりまとめに加えて、将来のミリ波VLBIのさらなる性能向上のため、新たな観測局の検討や開発を実施するとともに、新たな解析手法の検討を行った。新たな観測局としては、ALMAのTotal Power ArrayのVLBI局化について関係者と検討を進めたほか、野辺山宇宙電波観測所45mの望遠鏡の1mm帯の観測の可能性についても議論を行った。また、さらに将来の可能性として、ミリ波スペースVLBI衛星BHEX（Black Hole Explorer）について、米国など世界の共同研究者と実現に向けた検討を実施した。解析手法の開発面では最適輸送法に基づく動画解析法のコードを完成させた。

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

M87の動画解析のためのデータ取得が進み、動画の２コマ目に関する成果が得られたり、多波長キャンペーンからも時間変動の重要性が改めて示されるなど、当該分野に関して想定していた通りの興味深い成果が得られた。また、将来に向けた新たな検討が国際共同研究として進むなど、国際的に新たな進展が見られたため、おおむねに順調に研究が進んでいると判断する。

Strategy for Future Research Activity

これまで得られたデータの解析と成果出版を進め、延長後の最終年度として成果のとりまとめを実施する。さらに、本研究で発展した国際共同研究を今後さらに進展させて成果を創出することを目指し、次期の研究計画を立案してその実施準備を進める。

Research Products

• [Int'l Joint Research] ハーバード大学/マサチューセッツ工科大学/アリゾナ大学(米国)
• [Int'l Joint Research] ペリメーター理論物理研究所(カナダ)
• [Int'l Joint Research] マックスプランク電波天文研究所(ドイツ)
• [Int'l Joint Research] 韓国天文研究院(韓国)
• [Int'l Joint Research] 台湾中央研究院(その他の国・地域（台湾）)
• [Int'l Joint Research] ハーバード大学/マサチューセッツ工科大学/アリゾナ大学(米国)
• [Int'l Joint Research] ペリメーター理論物理研究所(カナダ)
• [Int'l Joint Research] マックスプランク電波天文研究所(ドイツ)
• [Int'l Joint Research] 韓国天文研究院(韓国)
• [Int'l Joint Research] 台湾中央研究院(その他の国・地域)
• [Int'l Joint Research] ハーバード大学/マサチューセッツ工科大学/アリゾナ大学(米国)
• [Int'l Joint Research] ペリメーター理論物理学研究所(カナダ)
• [Int'l Joint Research] マックスプランク電波天文研究所(ドイツ)
• [Int'l Joint Research] 韓国天文研究院(韓国)
• [Int'l Joint Research] 台湾中央研究院(その他の国・地域)
• [Int'l Joint Research] マサチューセッツ工科大学/ハーバード大学/アリゾナ大学(米国)
• [Int'l Joint Research] ペリメーター理論物理学研究所(カナダ)
• [Int'l Joint Research] マックスプランク電波天文研究所(ドイツ)
• [Int'l Joint Research] 韓国天文研究院(韓国)
• [Int'l Joint Research] 台湾中央研究院(その他の国・地域)
• [Int'l Joint Research]
• [Int'l Joint Research] MIT Haystack Observatory/Harvard/Smithsonian CfA/University of Arizona(米国)
• [Int'l Joint Research] The Instituto Astrofosica Andalucia(スペイン)
• [Int'l Joint Research] MIT Haystack Observatory/Harvard/Smithsonian CfA(米国)
• [Int'l Joint Research] The Instituto Astrofosica Andalucia(スペイン)
• [Int'l Joint Research] KASI(韓国)
• [Journal Article] The persistent shadow of the supermassive black hole of M87: II. Model comparisons and theoretical interpretations (2025)
  • Author(s): Event Horizon Telescope Collaboreation, Kazunori Akiyama, Tomohisa Kawashima, et al.
  • Journal Title: Astronomy & Astrophysics Volume: 693 Pages: A265-A265
  • DOI: 10.1051/0004-6361/202451296
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Trigonometric parallax and proper motion of Sagittarius A* measured by VERA using the new broad-band back-end system OCTAVE-DAS (2024)
  • Author(s): Oyama T., Nagayama T., Yamauchi A., Sakai D., Imai H., Honma M., Asakura Y, Hada K., Hagiwara Y., Hirota T., Jike T., Kono Y., Suzuki S., Kobayashi H., Kawaguchi N.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 76 Issue: 2 Pages: 163-174
  • DOI: 10.1093/pasj/psad088
  • Peer Reviewed
• [Journal Article] The Black Hole Explorer: motivation and vision (2024)
  • Author(s): Johnson M. D., et al., including Honma M.
  • Journal Title: Proceedings of the SPIE Volume: 13092 Pages: 1-52
  • DOI: 10.1117/12.3019835
  • Int'l Joint Research
• [Journal Article] Broadband multi-wavelength properties of M87 during the 2018 EHT campaign including a very high energy flaring episode (2024)
  • Author(s): Algaba J. C.、Balokovic M.、Chandra S.、Cheong W.-Y.、Cui Y.-Z.、D’Ammando F.、Falcone A. D.、Ford N. M.、Giroletti M.、Goddi C.、Gurwell M. A.、Hada K.、Haggard D.、Jorstad S.、Kaur A.、Kawashima T.、Kerby S.、Kim J.-Y.、Kino M.、Kravchenko E. V.、Lee S.-S.、Lu R.-S.、Markoff S.、Michail J.、略、Mizuno T.、他
  • Journal Title: Astronomy & Astrophysics Volume: 692 Pages: A140-A140
  • DOI: 10.1051/0004-6361/202450497
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The persistent shadow of the supermassive black hole of M 87. I. Observations, calibration, imaging, and analysis (2024)
  • Author(s): Event Horizon Telescope Collaboration et al., incluing M. Honma, S. Ikeda, M. Sasada
  • Journal Title: Astronomy & Astronphysics Volume: 681 Pages: A79-A79
  • DOI: 10.1051/0004-6361/202347932
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization (2023)
  • Author(s): Event Horizon Telescope Collaboration et al., incluing M. Honma, S. Ikeda, M. Sasada
  • Journal Title: Astrophysical Journal Letters Volume: 957 Issue: 2 Pages: L20-L20
  • DOI: 10.3847/2041-8213/acff70
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Precessing jet nozzle connecting to a spinning black hole in M87 (2023)
  • Author(s): Cui Y. et al., incluing M. Honma
  • Journal Title: Nature Volume: 621 Issue: 7980 Pages: 711-715
  • DOI: 10.1038/s41586-023-06479-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Spectral analysis of a parsec-scale jet in M 87: Observational constraint on the magnetic field strengths in the jet (2023)
  • Author(s): Ro, H. et al., including M. Honma
  • Journal Title: Astronomy & Astrophysics Volume: 673 Pages: A159-A159
  • DOI: 10.1051/0004-6361/202142988
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A ring-like accretion structure in M87 connecting its black hole and jet (2023)
  • Author(s): Ru L. et al., including M. Honma
  • Journal Title: Nature Volume: 616 Issue: 7958 Pages: 686-690
  • DOI: 10.1038/s41586-023-05843-w
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Super-Resolved Image of M87 Observed with East Asian VLBI Network (2023)
  • Author(s): Tazaki F., et al., including Honma, M.,
  • Journal Title: Galaxies Volume: 11 Issue: 2 Pages: 39-39
  • DOI: 10.3390/galaxies11020039
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way (2022)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 930 Issue: 2 Pages: L12-L12
  • DOI: 10.3847/2041-8213/ac6674
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multiwavelength Observations, Data Processing, and Calibration (2022)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 930 Issue: 2 Pages: L13-L13
  • DOI: 10.3847/2041-8213/ac6675
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Sagittarius A* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole (2022)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 930 Issue: 2 Pages: L14-L14
  • DOI: 10.3847/2041-8213/ac6429
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass (2022)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 930 Issue: 2 Pages: L15-L15
  • DOI: 10.3847/2041-8213/ac6736
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole (2022)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 930 Issue: 2 Pages: L16-L16
  • DOI: 10.3847/2041-8213/ac6672
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric (2022)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 930 Issue: 2 Pages: L17-L17
  • DOI: 10.3847/2041-8213/ac6756
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Intrinsic Structure of Sagittarius A* at 1.3 cm and 7 mm (2022)
  • Author(s): Cho Ilje、Zhao Guang-Yao、Kawashima Tomohisa、Kino Motoki、Akiyama Kazunori、Johnson Michael D.、Issaoun Sara、Moriyama Kotaro、Cheng Xiaopeng、Algaba Juan-Carlos、Jung Taehyun、Sohn Bong Won、Krichbaum Thomas P.、Wielgus Maciek、Hada Kazuhiro、他51名
  • Journal Title: The Astrophysical Journal Volume: 926 Issue: 2 Pages: 108-108
  • DOI: 10.3847/1538-4357/ac4165
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] East Asian VLBI Network observations of active galactic nuclei jets: imaging with KaVA+Tianma+Nanshan (2021)
  • Author(s): Cui Yu-Zhu、Hada Kazuhiro、他75名
  • Journal Title: Research in Astronomy and Astrophysics Volume: 21 Issue: 8 Pages: 205-205
  • DOI: 10.1088/1674-4527/21/8/205
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign (2021)
  • Author(s): EHT Multi-wavelength Science Working Group et al.
  • Journal Title: The Astrophysical Journal Letters Volume: 911 Issue: 1 Pages: L11-L11
  • DOI: 10.3847/2041-8213/abef71
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First M87 Event Horizon Telescope Results. VII. Polarization of the Ring (2021)
  • Author(s): Akiyama Kazunori et al. including Hiroshi Nagai
  • Journal Title: The Astrophysical Journal Letters Volume: 910 Issue: 1 Pages: L12-L12
  • DOI: 10.3847/2041-8213/abe71d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon (2021)
  • Author(s): Event Horizon Telescope Collaboration
  • Journal Title: The Astrophysical Journal Letters Volume: 910 Issue: 1 Pages: L13-L13
  • DOI: 10.3847/2041-8213/abe4de
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope (2020)
  • Author(s): Wielgus Maciek et al. including Hiroshi Nagai
  • Journal Title: The Astrophysical Journal Volume: 901 Issue: 1 Pages: 67-67
  • DOI: 10.3847/1538-4357/abac0d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Black Hole Spin Measurement Based on Time-domain VLBI Observations of Infalling Gas Clouds (2019)
  • Author(s): Moriyama K., Mineshige S., Honma M., Akiyama K.,
  • Journal Title: Astrophysical Journal Volume: 887 Issue: 2 Pages: 227-227
  • DOI: 10.3847/1538-4357/ab505b
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Event Horizon Explorer ミッション(II): EHE-Japan の目指すもの (2024)
  • Author(s): 本間希樹、他
  • Organizer: 日本天文学会春季年会
• [Presentation] 電波干渉計を用いた巨大ブラックホールの撮像 (2022)
  • Author(s): 本間希樹
  • Organizer: 電子情報通信学会 第37回信号処理シンポジウム
  • Invited
• [Presentation] EHTによる超巨大ブラックホールシャドウの直接撮像：現状と今後 (2020)
  • Author(s): 本間希樹、他
  • Organizer: 日本天文学会秋季年会
• [Book] 宇宙の奇跡を科学する (2021)
  • Author(s): 本間希樹
  • Total Pages: 255
  • Publisher: 扶桑社
  • ISBN: 9784594087357
• [Remarks] Event Horizon Telescope Japan
  • URL: https://www.miz.nao.ac.jp/eht-j/
• [Remarks] Event Horizon Telescope
  • URL: https://eventhorizontelescope.org/
• [Remarks] Black Hole Explorer
  • URL: https://www.blackholeexplorer.org/
• [Remarks] Event Horzon Telescope Japan
  • URL: https://www.miz.nao.ac.jp/eht-j/
• [Remarks] Event Horizon Telescope Japan
  • URL: https://www.miz.nao.ac.jp/eht-j/top