Observational studies of the massive star formation triggered by cloud-cloud collision

• Project/Area Number: 15K17607
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan (2016-2017); Nagoya University (2015)
• Principal Investigator: TORII Kazufumi 国立天文台, 野辺山宇宙電波観測所, 特任助教 (20444383)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 星形成 / 電波天文 / 分子雲 / 分子雲衝突 / 大質量星 / 大質量星形成 / 電波天文学 / 野辺山45m電波望遠鏡 / FUGIN / 銀河面サーベイ / 電波望遠鏡

Outline of Final Research Achievements

In this study, we aimed at understanding the mechanism of high-mass stars by observing natal molecular clouds in the various high-mass star forming regions. We especially focused on the high-mass star formation triggered by cloud-cloud collision (CCC).
First, we established observationally diagnostics of cloud-cloud collision by comparing between numerical calculations and observations of CCC, resulted in finding the importance of "complementary distribution" and "intermediate velocity feature" between two molecular clouds with different radial velocities. Second, we applied these diagnostics to the high-mass star forming regions in the galactic plane and Large Magellanic cloud. As a result, we discovered evidence of CCCs in more than 40 high-mass star forming regions. These results strongly indicate that CCC is one of the major modes of the high-mass star formation in the Galaxy.

Research Products

• [Int'l Joint Research] Imperial College London(英国)
• [Int'l Joint Research] Imperial College London(United Kingdom)
• [Int'l Joint Research] ケンブリッジ大学(英国)
• [Journal Article] Molecular clouds in the NGC6334 and NGC6357 region: Evidence for a 100 pc-scale cloud-cloud collision triggering the Galactic mini-starbursts (2018)
  • Author(s): Fukui Yasuo、Kohno Mikito、Yokoyama Keiko、Torii Kazufumi、Hattori Yusuke、Sano Hidetoshi、Nishimura Atsushi、Ohama Akio、Yamamoto Hiroaki、Tachihara Kengo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 41-41
  • DOI: 10.1093/pasj/psy017
  • Peer Reviewed / Open Access
• [Journal Article] Large-scale CO J=1-0 observations of the giant molecular cloud associated with the infrared ring N35 with the Nobeyama 45-m telescope (2018)
  • Author(s): Torii Kazufumi, Fujita, Shinji, Matsuo, Mitsuhiro, Nishimura, Atsushi, Kohno, Mikito, Kuriki, Mika, Tsuda, Yuya, Minamidani, Tetsuhiro, Umemoto, Tomofumi, Kuno, Nario, Hattori, Yusuke, Yoshiike, Satoshi, Ohama, Akio, Tachihara, Kengo, Shima, Kazuhiro, Habe, Asao, Fukui, Yasuo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 51-51
  • DOI: 10.1093/pasj/psy019
  • Peer Reviewed / Open Access
• [Journal Article] Formation of the young compact cluster GM24 triggered by a cloud-cloud collision (2018)
  • Author(s): Fukui Yasuo、Kohno Mikito、Yokoyama Keiko、Nishimura Atsushi、Torii Kazufumi、Hattori Yusuke、Sano Hidetoshi、Ohama Akio、Yamamoto Hiroaki、Tachihara Kengo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 44-44
  • DOI: 10.1093/pasj/psx144
  • Peer Reviewed / Open Access
• [Journal Article] FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN): Molecular clouds toward W33; possible evidence for a cloud-cloud collision triggering O-star formation (2018)
  • Author(s): Kohno Mikito、Torii Kazufumi、Tachihara Kengo、Umemoto Tomofumi、Minamidani Tetsuhiro、Nishimura Atsushi、Fujita Shinji、Matsuo Mitsuhiro、Yamagishi Mitsuyoshi、Tsuda Yuya、Kuriki Mika、Kuno Nario、Ohama Akio、Hattori Yusuke、Sano Hidetoshi、Yamamoto Hiroaki、Fukui Yasuo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 50-50
  • DOI: 10.1093/pasj/psx137
  • Peer Reviewed / Open Access
• [Journal Article] High-mass star formation possibly triggered by cloud-cloud collision in the HII region RCW34 (2018)
  • Author(s): Hayashi Katsuhiro、Sano Hidetoshi、Enokiya Rei、Torii Kazufumi、Hattori Yusuke、Kohno Mikito、Fujita Shinji、Nishimura Atsushi、Ohama Akio、Yamamoto Hiroaki、Tachihara Kengo、Hasegawa Yutaka、Kimura Kimihiro、Ogawa Hideo、Fukui Yasuo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 48-48
  • DOI: 10.1093/pasj/psx141
  • Peer Reviewed / Open Access
• [Journal Article] RCW36 in the Vela Molecular Ridge: Evidence for high-mass star-cluster formation triggered by cloud-cloud collision (2018)
  • Author(s): Sano Hidetoshi、Enokiya Rei、Hayashi Katsuhiro、Yamagishi Mitsuyoshi、Saeki Shun、Okawa Kazuki、Tsuge Kisetsu、Tsutsumi Daichi、Kohno Mikito、Hattori Yusuke、Yoshiike Satoshi、Fujita Shinji、Nishimura Atsushi、Ohama Akio、Tachihara Kengo、Torii Kazufumi、et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 43-43
  • DOI: 10.1093/pasj/psy006
  • NAID: 120006517678
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN). III. Possible evidence for formation of NGC 6618 cluster in M17 by cloud-cloud collision (2018)
  • Author(s): Nishimura Atsushi、Minamidani Tetsuhiro、Umemoto Tomofumi、Fujita Shinji、Matsuo Mitsuhiro、Hattori Yusuke、Kohno Mikito、Yamagishi Mitsuyoshi、Tsuda Yuya、Kuriki Mika、Kuno Nario、Torii Kazufumi、Tsutsumi Daichi、Okawa Kazuki、Sano Hidetoshi、Tachihara Kengo、Ohama Akio、Fukui Yasuo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 42-42
  • DOI: 10.1093/pasj/psx149
  • Peer Reviewed / Open Access
• [Journal Article] Detailed CO(J=1-0, 2-1, and 3-2) observations toward an HII region RCW32 in the Vela Molecular Ridge (2018)
  • Author(s): Enokiya Rei、Sano Hidetoshi、Hayashi Katsuhiro、Tachihara Kengo、Torii Kazufumi、Yamamoto Hiroaki、Hattori Yusuke、Hasegawa Yutaka、Ohama Akio、Kimura Kimihiro、Ogawa Hideo、Fukui Yasuo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中 Issue: SP2 Pages: 49-49
  • DOI: 10.1093/pasj/psy015
  • Peer Reviewed / Open Access
• [Journal Article] CO observations of the molecular gas in the galactic HII region Sh2-48; Evidence for cloud-cloud collision as a trigger of high-mass star formation (2018)
  • Author(s): Torii Kazufumi, Hattori Yusuke, Matsuo Mitsuhiro, Fujita Shinji, Nishimura Atsushi, Kohno Mikito, Kuriki Mika, Tsuda Yuya, Minamidani Tetsuhiro, Umemoto Tomofumi, Kuno Nario, Yoshiike Satoshi, Ohama Akio, Tachihara Kengo, Fukui Yasuo, Shima Kazuhiro, Habe Asao, Haworth Thomas J.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] FOREST unbiased Galactic plane imaging survey with the Nobeyama 45 m telescope (FUGIN). I. Project overview and initial results (2017)
  • Author(s): Umemoto, Tomofumi et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 69 Issue: 5 Pages: 78-96
  • DOI: 10.1093/pasj/psx061
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Triggered O Star Formation in M20 via Cloud-Cloud Collision: Comparisons between High-resolution CO Observations and Simulations (2017)
  • Author(s): Torii, K., Hattori, Y., Hasegawa, K., Ohama, A., Haworth, T. J., Shima, K., Habe, A., Tachihara, K., Mizuno, N., Onishi, T., Mizuno, A., and Fukui, Y.
  • Journal Title: The Astrophysical Journal Volume: 835 Issue: 2 Pages: 142-153
  • DOI: 10.3847/1538-4357/835/2/142
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] A massive molecular outflow in the dense dust core AGAL G337.916-00.477 (2017)
  • Author(s): Torii, K., Hattori, Y., Hasegawa, K., Ohama, A., Yamamoto, H., Tachihara, K., Tokuda, K., Onishi, T., Hattori, Y., Ishihara, D., Kaneda, H., Fukui, Y.
  • Journal Title: The Astrophysical Journal Volume: 印刷中
  • Peer Reviewed / Open Access
• [Journal Article] The Two Molecular Clouds in RCW 38: Evidence for the Formation of the Youngest Super Star Cluster in the Milky Way Triggered by Cloud-Cloud Collision (2016)
  • Author(s): Fukui, Y.; Torii, K.; Ohama, A.; Hasegawa, K.; Hattori, Y.; Sano, H.; Ohashi, S.; Fujii, K.; Kuwahara, S.; Mizuno, N.; Dawson, J. R.; Yamamoto, H.; Tachihara, K.; Okuda, T.; Onishi, T.; Mizuno, A.
  • Journal Title: The Astrophysical Journal Volume: 820 Issue: 1 Pages: 26-42
  • DOI: 10.3847/0004-637x/820/1/26
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Cloud-Cloud Collision as a Trigger of the High-mass Star Formation: a Molecular Line Study in RCW120 (2015)
  • Author(s): Torii, K.; Hasegawa, K.; Hattori, Y.; Sano, H.; Ohama, A.; Yamamoto, H.; Tachihara, K.; Soga, S.; Shimizu, S.; Okuda, T.; Mizuno, N.; Onishi, T.; Mizuno, A.; Fukui, Y.
  • Journal Title: The Astrophysical Journal Volume: 806 Issue: 1 Pages: 7-27
  • DOI: 10.1088/0004-637x/806/1/7
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Isolating signatures of major cloud-cloud collisions using position-velocity diagrams (2015)
  • Author(s): Haworth, T. J.; Tasker, E. J.; Fukui, Y.; Torii, K.; Dale, J. E.; Shima, K.; Takahira, K.; Habe, A.; Hasegawa, K.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 450 Issue: 1 Pages: 10-20
  • DOI: 10.1093/mnras/stv639
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] High-mass Star Formation Triggered by Collision between CO Filaments in N159 West in the Large Magellanic Cloud (2015)
  • Author(s): Fukui, Yasuo; Harada, Ryohei; Tokuda, Kazuki; Morioka, Yuuki; Onishi, Toshikazu; Torii, Kazufumi et al.
  • Journal Title: The Astrophysical Journal Letters Volume: 807 Issue: 1 Pages: 4-9
  • DOI: 10.1088/2041-8205/807/1/l4
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Isolating signatures of major cloud-cloud collisions - II. The lifetimes of broad bridge features (2015)
  • Author(s): Haworth, T. J.; Shima, K.; Tasker, E. J.; Fukui, Y.; Torii, K.; Dale, J. E.; Takahira, K.; Habe, A.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 454 Issue: 2 Pages: 1634-1643
  • DOI: 10.1093/mnras/stv2068
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] 天の川銀河の分子雲観測と階層構造 (2018)
  • Author(s): 鳥居和史
  • Organizer: 「自然科学における階層と全体」シンポジウム
• [Presentation] FUGIN: FOREST Ultra-wide Galactic Plane Survey In Nobeyama (2017)
  • Author(s): 鳥居和史
  • Organizer: JCMT Users Meeting 2017
  • Place of Presentation: 南京（中国）
  • Year and Date: 2017-02-13
  • Int'l Joint Research
• [Presentation] FUGINが見た分子雲衝突 (2017)
  • Author(s): 鳥居和史
  • Organizer: 国立天文台研究集会「星形成と銀河構造における磁場の役割」
  • Invited
• [Presentation] 銀河中心領域の分子雲観測とMHD (2017)
  • Author(s): 鳥居和史
  • Organizer: MHD2017 磁気流体プラズマで探る高エネルギー天体現象研究会
  • Invited
• [Presentation] Nobeyama CO galactic plane survey (2017)
  • Author(s): 鳥居和史
  • Organizer: 2017 Asia-Pacific Regional IAU Meeting
  • Int'l Joint Research / Invited
• [Presentation] ALMAを用いた巨大星団RCW38に対する分子ガスと電離ガスの高分解能観測 (2017)
  • Author(s): 鳥居和史
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] 銀河面COサーベイを用いた大質量星/星団形成の研究 (2017)
  • Author(s): 鳥居和史
  • Organizer: 大小マゼラン雲における大質量星・星団形成
• [Presentation] 分子雲衝突が解き明かす大質量星形成の謎 (2017)
  • Author(s): 鳥居和史
  • Organizer: 星間現象ワークショップ
  • Place of Presentation: ホテルメルパルク名古屋（愛知県名古屋市）
  • Invited
• [Presentation] O star formation via cloud-cloud collision in M20 (2016)
  • Author(s): 鳥居和史
  • Organizer: VIALACTEA 2016
  • Place of Presentation: ローマ（イタリア）
  • Year and Date: 2016-09-26
  • Int'l Joint Research
• [Presentation] NRO 銀河面サーベイプロジェクト(FUGIN) ： Spitzer バブルN18 における分子雲衝突と大質量星形成 (2016)
  • Author(s): 鳥居和史
  • Organizer: 日本天文学会2016年秋季年会
  • Place of Presentation: 愛媛大学（愛媛県松山市）
  • Year and Date: 2016-09-14
• [Presentation] 巨大星団RCW38におけるO型星のフィードバックと分子雲の相互作用 (2016)
  • Author(s): 鳥居和史, 服部有祐, 長谷川敬亮, 大濱晶生, 佐野英俊, 山本宏昭, 立原研悟, 福井康雄 (名古屋 大学), 水野範和(国立天文台), 大西利和(大阪府立大学)
  • Organizer: 日本天文学会2016年春季年会
  • Place of Presentation: 首都大学東京
  • Year and Date: 2016-03-14
• [Presentation] サーベイデータで探る大質量星形成：分子雲衝突による誘発的星形成の観点から (2016)
  • Author(s): 鳥居和史
  • Organizer: 「あかり」サイエンスワークショップ
  • Place of Presentation: 国立天文台（東京都三鷹市）
  • Invited
• [Presentation] Spitzer bubble CO survey (2015)
  • Author(s): 鳥居和史, 服部有祐, 長谷川敬亮, 大濱晶生, 佐野英俊, 山本宏昭, 立原研悟, 福井康雄 (名古屋 大学), 水野範和(国立天文台), 大西利和(大阪府立大学)
  • Organizer: ミニワークショップ「分子雲衝突でさぐる星形成」
  • Place of Presentation: 北海道大学
  • Year and Date: 2015-10-29
  • Int'l Joint Research
• [Presentation] High-mass star formation via cloud-cloud collision (2015)
  • Author(s): 鳥居和史
  • Organizer: ALMA/45m/ASTE/Mopra Users Meeting
  • Place of Presentation: 国立天文台
  • Year and Date: 2015-10-20
  • Int'l Joint Research
• [Presentation] Massive Star Formation Triggered by Collisions of Molecular Clouds (2015)
  • Author(s): 鳥居和史
  • Organizer: TAO/SWIMS サイエンスワークショップ2015
  • Place of Presentation: 東京大学天文学教育研究センター
  • Year and Date: 2015-09-17
  • Int'l Joint Research / Invited
• [Presentation] SpitzerバブルS36に対する分子雲観測：分子雲衝突による大質量星形成 (2015)
  • Author(s): 鳥居和史, 服部有祐, 長谷川敬亮, 大濱晶生, 佐野英俊, 山本宏昭, 立原研悟, 福井康雄 (名古屋 大学), 水野範和(国立天文台), 大西利和(大阪府立大学)
  • Organizer: 日本天文学会2015年秋季年会
  • Place of Presentation: 甲南大学
  • Year and Date: 2015-09-09
• [Presentation] Formation of the twin galactic starburst regions NGC6334 and NGC6357 (2015)
  • Author(s): Torii Kazufumi; Hasegawa Keisuke; Ohama Akio; Yamamoto Hiroaki; Tachihara Kengo; Fukui Yasuo
  • Organizer: IAU General Assembly, Meeting #29
  • Place of Presentation: 米国ハワイ
  • Year and Date: 2015-08-11
  • Int'l Joint Research