Development of Polarization Sky Simulator toward Discovering the Intergalactic Medium

• Project/Area Number: 15K17614
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan (2017); Kagoshima University (2015-2016)
• Principal Investigator: Akahori Takuya 国立天文台, 水沢VLBI観測所, 特任研究員 (70455913)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 電波天文学 / 磁場 / 偏波 / 宇宙大規模構造 / SKA計画

Outline of Final Research Achievements

This research revealed polarization properties of various astronomical objects toward the Square Kilometre Array (SKA), and developed Faraday tomography which is thought to be a key technology for future radio polarimetry. We achieved formulation of depolarization in galaxies, and revealed that Fast Radio Bursts (FRBs) can be ideal extragalactic polarized sources for the study of the intergalactic magnetic field. We observed galaxy clusters and a local nebula. We applied Faraday tomography to the data, and achieved to distinguish some components along the lines-of-sight. We clarified how to apply Faraday tomography to the study of external galaxies, and showed the capability of sparse-modeling-based Faraday tomography for the study of the intergalactic magnetic field.

Research Products

• [Int'l Joint Research] SRON/Radboud University Nijmegen(オランダ)
• [Int'l Joint Research] UNIST(韓国)
• [Int'l Joint Research] University of Toronto(Canada)
• [Int'l Joint Research] Radboud University Nijmegen(オランダ)
• [Int'l Joint Research] UNIST(韓国)
• [Int'l Joint Research] University of Toronto(Canada)
• [Int'l Joint Research] University of Sydney(Australia)
• [Int'l Joint Research] University of Cape Town(南アフリカ)
• [Int'l Joint Research] Radboud University Nijmegen/ASTRON(オランダ)
• [Int'l Joint Research]
• [Journal Article] Magnetic field analysis of the bow and terminal shock of the SS 433 jet (2018)
  • Author(s): Sakemi H., Machida M., Akahori T., Nakanishi H., Akamatsu H., Kurahara K., Farnes J.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 1-14
  • DOI: 10.1093/pasj/psy003
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Cosmic magnetism in centimeter- and meter-wavelength radio astronomy (2017)
  • Author(s): Akahori Takuya、Nakanishi Hiroyuki、Sofue Yoshiaki、Fujita Yutaka、Ichiki Kiyotomo、Ideguchi Shinsuke、Kameya Osamu、Kudoh Takahiro、Kudoh Yuki、Machida Mami、Miyashita Yoshimitsu、Ohno Hiroshi、Ozawa Takeaki、Takahashi Keitaro、Takizawa Motokazu、Yamazaki Dai G
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 1 Pages: 1-44
  • DOI: 10.1093/pasj/psx123
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Study of the Vertical Magnetic Field in Face-on Galaxies Using Faraday Tomography (2017)
  • Author(s): Ideguchi Shinsuke、Tashiro Yuichi、Akahori Takuya、Takahashi Keitaro、Ryu Dongsu
  • Journal Title: The Astrophysical Journal Volume: 843 Issue: 2 Pages: 146-146
  • DOI: 10.3847/1538-4357/aa79a1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Properties of the cosmological filament between two clusters: A possible detection of a large-scale accretion shock by Suzaku (2017)
  • Author(s): Akamatsu H.、Fujita Y.、Akahori T.、Ishisaki Y.、Hayashida K.、Hoshino A.、Mernier F.、Yoshikawa K.、Sato K.、Kaastra J. S.
  • Journal Title: Astronomy & Astrophysics Volume: 606 Pages: 1-8
  • DOI: 10.1051/0004-6361/201730497
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Probing WHIM around Galaxy Clusters with Fast Radio Bursts and the Sunyaev-Zel'dovich effect (2017)
  • Author(s): Y. Fujita, T, Akahori, K. Umetsu, C. L. Sarazin, & K.-W. Wong
  • Journal Title: The Astrophysical Journal Volume: 834 Issue: 1 Pages: 13-13
  • DOI: 10.3847/1538-4357/834/1/13
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Interacting Large-Scale Magnetic Fields and Ionised Gas in the W50/SS433 System (2017)
  • Author(s): J. Farnes, B. M. Gaensler, C. Purcell, X. H. Sun, M. Haverkorn, E. Lenc, S. P. O’Sullivan, T. Akahori
  • Journal Title: Monthly Notice of the Royal Astronomical Society Volume: 467 Issue: 4 Pages: 4777-4801
  • DOI: 10.1093/mnras/stx338
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Fast Radio Bursts as Probes of Magnetic Fields in Filaments of Galaxies (2016)
  • Author(s): T. Akahori, D. Ryu, B. M. Gaensler
  • Journal Title: The Astrophysical Journal Volume: 824 Issue: 2 Pages: 123-132
  • DOI: 10.3847/0004-637x/824/2/105
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] The Sunyaev-Zel'dovich effect at 5″: RX J1347.5-1145 imaged by ALMA (2016)
  • Author(s): T. Kitayama, S. Ueda, S. Takakuwa, T. Tsutsumi, E. Komatsu, T. Akahori, D. Iono, T. Izumi, R. Kawabe, K. Kohno, H. Matsuo, N. Ota, Y. Suto, M. Takizawa, K. Yoshikawa
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 68 Issue: 5 Pages: 88-106
  • DOI: 10.1093/pasj/psw082
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Discovery of a nearby early-phase major cluster merger CIZA J1358.9-4750 (2015)
  • Author(s): Y. Kato, K. Nakazawa, L. Gu, T. Akahori, M. Takizawa, Y. Fujita & K. Makishima
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 67 Issue: 4 Pages: 71-71
  • DOI: 10.1093/pasj/psv029
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] JVLA S- and X-band polarimetry of the merging cluster Abell 2256 (2015)
  • Author(s): Takeaki Ozawa, Hiroyuki Nakanishi, Takuya Akahori, Kenta Anraku, Motokazu Takizawa, Ikumi Takahashi, Sachiko Onodera, Yuya Tsuda, Yoshiaki Sofue
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 67 Issue: 6 Pages: 110-110
  • DOI: 10.1093/pasj/psv082
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Using the Rotation Measure Grid to Reveal the Mysteries of the Magnetized Universe (2015)
  • Author(s): M. Johnston-Hollitt, F. Govoni, R. Beck, S. Dehghan, L. Pratley, T. Akahori, G. Heald, I. Agudo, A. Bonafede, E. Carretti, T. Clarke, S. Colafrancesco, T.A. Ensslin, L. Feretti, B. Gaensler, M. Haverkorn, S.A. Mao, N. Oppermann, L. Rudnick, A. Scaife, D. Schnitzeler, J. Stil, A. R. Taylor, and V. Vacca
  • Journal Title: Advancing Astrophysics with the Square Kilometre Array Volume: 92 Pages: 1-18
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] SKA Deep Field and Cosmic Magnetism (2015)
  • Author(s): A. R. Taylor, I. Agudo, T. Akahori, R. Beck, B. M. Gaensler, G. H. Heald, M. Johnston-Hollitt, M. Langer, L. Rudnick, D. Ryu, A. Scaife, D. Schleicher, J. M. Stil
  • Journal Title: Advancing Astrophysics with the Square Kilometre Array Volume: 113 Pages: 1-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Measuring Magnetism in the Milky Way with the Square Kilometre Array (2015)
  • Author(s): M. Haverkorn, T. Akahori, E. Carretti, K. Ferriere, P. Frick, B. Gaensler, G. Heald, M. Johnston-Hollitt, D. Jones, T. Landecker, S. A. Mao, A. Noutsos, N. Oppermann, W. Reich, T. Robishaw, A. Scaife, D. Schnitzeler, R. Stepanov, X. Sun, R. Taylor
  • Journal Title: Advancing Astrophysics with the Square Kilometre Array Volume: 96 Pages: 1-19
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Broadband Polarimetry with the Square Kilometre Array: A Unique Astrophysical Probe (2015)
  • Author(s): B. M. Gaensler, I. Agudo, T. Akahori, J. Banfield, R. Beck, E. Carretti, J. Farnes, M. Haverkorn, G. Heald, D. Jones, T. Landecker, S. A. Mao, R. Norris, S. O'Sullivan, L. Rudnick, D. Schnitzeler, N. Seymour, X. Sun
  • Journal Title: Advancing Astrophysics with the Square Kilometre Array Volume: 103 Pages: 1-13
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Unravelling the Origin of Large-Scale Magnetic Fields in Galaxy Clusters (2015)
  • Author(s): A. Bonafede, F. Vazza, M. Brüggen, T. Akahori, E. Carretti, S. Colafrancesco, L. Feretti, C. Ferrari, G. Giovannini, F. Govoni, M. Johnston-Hollitt, M. Murgia, L. Rudnick, A. Scaife, V. Vacca
  • Journal Title: Advancing Astrophysics with the Square Kilometre Array Volume: 95 Pages: 1-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] SKAによる突発天体 (2018)
  • Author(s): 赤堀卓也
  • Organizer: SKAJPパルサー・突発天体研究会
  • Int'l Joint Research / Invited
• [Presentation] 高速電波バーストのUHF全帯域観測で探る宇宙磁場 (2017)
  • Author(s): 赤堀卓也
  • Organizer: 重力波＆電磁波サーベイ＆突発天体研究会
  • Place of Presentation: 山口大学（山口県・山口市）
  • Year and Date: 2017-03-23
  • Invited
• [Presentation] 衝突銀河団CIZA J1358.9-4750領域の広がった電波放射の探査 (2017)
  • Author(s): 赤堀卓也, 加藤佑一, 中澤知洋, 小澤武揚, Gu Lyli, 滝沢元和, 藤田裕, 中西裕之, 岡部信広, 牧島一夫
  • Organizer: 日本天文学会2017春季年会
  • Place of Presentation: 九州大学（福岡県・福岡市）
  • Year and Date: 2017-03-15
• [Presentation] UHF全帯域で探る宇宙磁場・パルサー・突発現象・星間物質 (2017)
  • Author(s): 赤堀卓也
  • Organizer: 宇宙電波懇談会シンポジウム
  • Place of Presentation: 国立天文台（東京都・三鷹市）
  • Year and Date: 2017-02-22
  • Invited
• [Presentation] Exploring the Diffuse Ionized Gas in Our Galaxy by means of Long Wavelength Radio Observation (2016)
  • Author(s): 赤堀卓也
  • Organizer: 第六回DTAシンポジウム
  • Place of Presentation: 国立天文台（東京都・三鷹市）
  • Year and Date: 2016-11-24
  • Invited
• [Presentation] The Cosmic Web: A new discovery space in the SKA generation (2016)
  • Author(s): T. Akahori
  • Organizer: SKA 2016: Science for the SKA generation
  • Place of Presentation: Goa (India)
  • Year and Date: 2016-11-07
  • Int'l Joint Research
• [Presentation] 宇宙磁場・星間現象・パルサー・突発天体が集合する意義～汎用大型観測装置SKAのUHF帯コメンサルサーベイ～ (2016)
  • Author(s): 赤堀卓也
  • Organizer: 日本SKA合同サイエンス会議「銀河系内現象から大規模構造へ」
  • Place of Presentation: ルーセントタカミヤ（山形県・山形市）
  • Year and Date: 2016-10-27
• [Presentation] Recent SKA-Related Activities in Japan (2016)
  • Author(s): T. Akahori
  • Organizer: Asia-Pacific Radio Science Conference
  • Place of Presentation: Seoul (Korea)
  • Year and Date: 2016-08-21
  • Int'l Joint Research / Invited
• [Presentation] Probing the IGM (2016)
  • Author(s): T. Akahori
  • Organizer: Boutique & Experiments 2016: Radio
  • Place of Presentation: Pasadena (USA)
  • Year and Date: 2016-07-21
  • Int'l Joint Research / Invited
• [Presentation] The SKA Project (2016)
  • Author(s): T. Akahori
  • Organizer: Australia-Japan Joint Workshop on Low Frequency Astrometry
  • Place of Presentation: 鹿児島大学（鹿児島県鹿児島市）
  • Year and Date: 2016-03-28
  • Int'l Joint Research / Invited
• [Presentation] SKAで探る宇宙 (2016)
  • Author(s): 赤堀卓也
  • Organizer: 高エネルギー宇宙物理学懇談会シンポジウム
  • Place of Presentation: 東京理科大学（東京都新宿区）
  • Year and Date: 2016-03-23
  • Invited
• [Presentation] SKA時代のFRBを用いた銀河間物質の探査 (2016)
  • Author(s): 赤堀卓也, D. Ryu, B. M. Gaensler
  • Organizer: 日本天文学会
  • Place of Presentation: 首都大学東京（東京都八王子市）
  • Year and Date: 2016-03-14
• [Presentation] センチ波偏波観測のサイエンスと将来計画 (2016)
  • Author(s): 赤堀卓也
  • Organizer: 宇宙電波懇談会シンポジウム
  • Place of Presentation: 国立天文台（東京都三鷹市）
  • Year and Date: 2016-03-09
  • Invited
• [Presentation] センチ波偏波観測のサイエンスと将来計画 (2016)
  • Author(s): 赤堀卓也
  • Organizer: 偏波・偏光研究会
  • Place of Presentation: 茨城大学（茨城県水戸市）
  • Year and Date: 2016-01-28
  • Invited
• [Presentation] MWAによる宇宙磁場研究 (2016)
  • Author(s): 赤堀卓也
  • Organizer: MWA-Japanキックオフミーティング
  • Place of Presentation: 名古屋大学（愛知県・名古屋市）
• [Presentation] FRBで探る銀河間物質 (2015)
  • Author(s): 赤堀卓也
  • Organizer: 日本SKAサイエンス会議「宇宙磁場」2015(第4回)
  • Place of Presentation: 鹿児島大学（鹿児島県鹿児島市）
  • Year and Date: 2015-09-17
• [Presentation] SKAで探るミッシングバリオンと銀河間磁場 (2015)
  • Author(s): 赤堀卓也
  • Organizer: 日本天文学会
  • Place of Presentation: 甲南大学（兵庫県神戸市）
  • Year and Date: 2015-09-09
• [Presentation] Proving RM due to the IGMF with SKA (2015)
  • Author(s): T. Akahori
  • Organizer: Origin, Evolution, and Signature of Cosmological Magnetic Fields
  • Place of Presentation: Stockholm (Sweden)
  • Year and Date: 2015-06-22
  • Int'l Joint Research