Unraveling the Nature of Radio Jets Governing the Formation of Massive Galaxies

• Project/Area Number: 21K13968
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Yamashita Takuji 国立天文台, ハワイ観測所, 特任研究員 (20800759)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2022: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2021: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 銀河 / 活動銀河核 / ブラックホール / 電波 / 赤外線 / 大規模データ / 光赤外線 / 銀河天文学 / 超巨大ブラックホール / 電波銀河 / すばる望遠鏡

Outline of Research at the Start

大質量銀河は宇宙初期から既に形成していたことが近年示されているが、そのような早期の質量成長は現在に至るまでに速やかに停止される必要があり、その機構は謎である。有力な候補機構として、電波銀河が持つ超巨大ブラックホールに駆動された電波ジェットがある。しかし、宇宙初期の電波銀河の探査は著しく停滞しているため理解が進んでいない。本研究は、最新の高感度かつ広域の可視光探査「すばる望遠鏡Hyper Suprime-Camサーベイ」大規模データと広域電波探査データを用いて、初期宇宙における電波銀河の探査を開拓し、宇宙初期の大質量銀河と電波ジェットの相互作用を評価し、大質量銀河の形成史を探る。

Outline of Final Research Achievements

The nature of massive galaxies suggests that they were already formed in the early universe, and radio-jets emitted by radio galaxies are strong candidates for the mechanism that halts their further mass growth. However, exploration of radio galaxies in the distant universe has been limited so far, and the understanding of the relationship between the formation of massive galaxies in the early universe and radio-jets has been inadequate. This research aims to pioneer the exploration of radio galaxies in the early universe using data from the Subaru Hyper Suprime-Cam survey and wide-field radio surveys, in order to elucidate the relationship between the formation of massive galaxies in the early universe and radio jets. In this project, we constructed, for the first time, a sample of distant radio galaxies with a redshift of 4 or higher and conducted follow-up spectroscopic observations, revealing the large-scale structures associated with these distant radio galaxies.

Academic Significance and Societal Importance of the Research Achievements

現在の宇宙に存在する全星質量の多くを占める大質量銀河の形成と進化を解き明かすことは天文学の一大課題である。本研究では、最新のすばる望遠鏡Hyper Suprime-Camサーベイデータと電波サーベイデータを活用することで、高赤方偏移での電波銀河サンプル構築方法を確立した。本研究が先駆けとなり、本手法による遠方電波銀河探査と関連する研究が国内外で始動し、停滞していた遠方電波銀河探査を打開することができた。

Research Products

• [Int'l Joint Research] NSF's NOIRLab(米国)
• [Int'l Joint Research] University of Bath(英国)
• [Int'l Joint Research] University of Bath/University College London(英国)
• [Int'l Joint Research] NSF's NOIRLab(米国)
• [Int'l Joint Research] ASIAA(その他の国・地域)
• [Journal Article] Detection of Extended Millimeter Emission in the Host Galaxy of 3C 273 and Its Implications for QSO Feedback via High Dynamic Range ALMA Imaging (2022)
  • Author(s): Shinya Komugi, Yoshiki Toba, Yoshiki Matsuoka, Toshiki Saito, Takuji Yamashita
  • Journal Title: Astrophysical Journal Volume: 930 Issue: 1 Pages: 1-7
  • DOI: 10.3847/1538-4357/ac616e
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VII. Redshift Evolution of Radio Galaxy Environments at z = 0.3?1.4 (2022)
  • Author(s): Uchiyama Hisakazu、Yamashita Takuji、Nagao Tohru、Ichikawa Kohei、Toba Yoshiki、Ishikawa Shogo、Kubo Mariko、Kajisawa Masaru、Kawaguchi Toshihiro、Kawakatu Nozomu、Lee Chien-Hsiu、Noboriguchi Akatoki
  • Journal Title: The Astrophysical Journal Volume: 934 Issue: 1 Pages: 68-68
  • DOI: 10.3847/1538-4357/ac77ee
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). IX. The most overdense region at <i>z</i> ? 5 inhabited by a massive radio galaxy (2022)
  • Author(s): Uchiyama Hisakazu、Yamashita Takuji、Nagao Tohru、Ono Yoshiaki、Toshikawa Jun、Ichikawa Kohei、Kawakatu Nozomu、Kajisawa Masaru、Toba Yoshiki、Matsuoka Yoshiki、Kubo Mariko、Imanishi Masatoshi、Ito Kei、Kawaguchi Toshihiro、Lee Chien-Hsiu、Saito Tomoki
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 74 Issue: 6 Pages: 27-32
  • DOI: 10.1093/pasj/psac075
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VI. Distant Filamentary Structures Pointed Out by High-z Radio Galaxies at z ? 4 (2022)
  • Author(s): Uchiyama Hisakazu、Yamashita Takuji、Toshikawa Jun、Kashikawa Nobunari、Ichikawa Kohei、Kubo Mariko、Ito Kei、Kawakatu Nozomu、Nagao Tohru、Toba Yoshiki、Ono Yoshiaki、Harikane Yuichi、Imanishi Masatoshi、Kajisawa Masaru、Lee Chien-Hsiu、Liang Yongming
  • Journal Title: The Astrophysical Journal Volume: 926 Issue: 1 Pages: 76-76
  • DOI: 10.3847/1538-4357/ac441c
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS): Co-evolution of Radio Galaxies and the Surrounding Galaxies at Various Cosmic Epochs (2023)
  • Author(s): Hisakazu Uchiyama, Takuji Yamashita, et al.
  • Organizer: Tracing the SMBH growth: outlook beyond the HSC-SSP, and future collaborations
  • Int'l Joint Research
• [Presentation] The Nature of New z~4 High-z Radio Galaxies from HSC-SSP and VLA/FIRST (2023)
  • Author(s): Yuta Yamamoto, Tohru Nagao, Hisakazu Uchiyama, Takuji Yamashita, Yoshiki Toba, Mariko Kubo, Akatoki Noboriguchi, Yoshiaki Ono, Yuichi Harikane, and the WERGS team
  • Organizer: Subaru Users Meeting FY2022
• [Presentation] 高赤方偏移電波銀河の分光追観測 (2022)
  • Author(s): 山下拓時, WERGS コラボレーション
  • Organizer: 日本天文学会2022年秋季年会
• [Presentation] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS): z = 4.72 の電波銀河周辺環境 (2022)
  • Author(s): 内山久和, 山下拓時, 長尾透, 鍛冶澤賢, 松岡良樹, 久保真理子, 小野宜昭, 利川潤, 市川幸平, 川勝望, 鳥羽儀樹, 今西昌俊, 伊藤慧, 川口俊宏, Chien-Hsiu Lee, 斎藤智樹
  • Organizer: 日本天文学会2022年秋季年会
• [Presentation] 赤方偏移 4 における遠方電波銀河の探査と性質調査 (2022)
  • Author(s): 山本優太, 長尾透, 久保真理子, 内山久和, 山下拓時, 鳥羽儀樹, 登口暁, 播金優一, 小野宜昭
  • Organizer: 日本天文学会2022年秋季年会
• [Presentation] WERGS project status and follow-up observations (2022)
  • Author(s): Takuji Yamashita, Wanqiu He, Kohei Ichikawa, Bovornpratch Vijarnwannaluk, Hisakazu Uchiyama, Tohru Nagao, Yuta Yamamoto, and WERGS collaboration
  • Organizer: Tracing the SMBH growth: outlook beyond the HSC-SSP, and future collaborations
  • Int'l Joint Research
• [Presentation] A new z~4 radio galaxy survey with HSC-SSP and VLA/FIRST (2022)
  • Author(s): Yuta Yamamoto, Tohru Nagao, Kubo Mariko, Hisakazu Uchiyama, Takuji Yamashita, Yoshiki Toba, Akatoki Noboriguchi, Yuichi Harikane, Yoshiaki Ono
  • Organizer: Tracing the SMBH growth: outlook beyond the HSC-SSP, and future collaborations
  • Int'l Joint Research
• [Presentation] Radio galaxy catalog in the Subaru/HSC Joint catalog field (2022)
  • Author(s): Kohei Ichikawa, Itsna Khoirul Fitriana, Takuji Yamashita, Hikaru Fukuchi, Masayuki Akiyama, Yu-Yen Chang, Andrew Battisti, Elisabete da Cunha, WERGS team, HSC-Joint catalog team
  • Organizer: Tracing the SMBH growth: outlook beyond the HSC-SSP, and future collaborations
  • Int'l Joint Research
• [Presentation] GREX-PLUSによる電波銀河観測 (2022)
  • Author(s): 山下拓時
  • Organizer: GREX-PLUS サイエンス検討会 FY2021
  • Invited
• [Presentation] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS): z = 0.3 － 1.4 の電波銀河周辺環境の統計的理解 (2022)
  • Author(s): 内山 久和 (愛媛大), 山下 拓時 (国立天文台), 長尾 透, 久保 真理子, 鍛冶澤 賢 (愛媛大), 市川 幸平, 登口 暁 (東北大), 鳥羽 儀樹 (京都大), 石川 将吾 (国立天文台), 川口 俊宏 (尾道大), 川勝 望 (呉高 専), Chien-Hsiu Lee (NOIRLab), and WERGS members
  • Organizer: 日本天文学会2022年春季年会
• [Presentation] Radio galaxies in the early universe found in Subaru HSC-SSP (2021)
  • Author(s): Takuji Yamashita
  • Organizer: ALMA-J Seminar
  • Int'l Joint Research / Invited
• [Presentation] A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS): z ~ 4 の暗い電波銀河周辺環境の統計的理解 (2021)
  • Author(s): 内山 久和 (愛媛大), 山下 拓時 (国立天文台), 利川 潤 (Bath univ.), 柏川 伸成 (東京大), 市川 幸平 (東北大), 久保 真理子, 長尾 透, 鍛冶澤 賢 (愛媛大), 鳥羽 儀樹 (京都大), 伊藤 慧, Yongming Liang (総研大), 川勝 望 (呉高専), 小野 宜昭, 播金 優一 (宇宙線研), 今西 昌俊 (国立天文台), Chien-Hsiu Lee (NOIRLab)
  • Organizer: 日本天文学会2021年秋季年会