Understanding Accretion of Young Massive Protostars

2020 Fiscal Year Annual Research Report

• Project/Area Number: 19K14774
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: ZHANG YICHEN 国立研究開発法人理化学研究所, 開拓研究本部, 基礎科学特別研究員 (50791943)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: Massive Star Formation / Accretion Disk

Outline of Annual Research Achievements

The whole project is to search, identify, and study the rotationally supported disks around massive protostars. In 2019, we have published a paper on the massive protostellar source G339 in the Astrophysical Journal, which we have reported direct observation of the transition from an infalling envelope to a rotationally supported disk accompanied by change of chemical signatures. This is the first time that such transition has been identified with chemical signatures in massive star formation, which provides important guide for our future search for such sources. In 2019, we also published a paper about another massive protostar G45 in the Astrophysical Journal Letters, which we have identify the disk via observation of recombination lines of ionized gas, which provide another approach to search disks around massive protostars. In 2020, we published a paperin the Astrophysical Journal Letters about another massive protostellar source IRAS16547, in which we have identified clear chemical patterns with certain molecules exclusively trace the rotationally supported disks, which may be used as reliable disk diagnostic tools in the future. In 2019, we have applied following-up observations of the ALMA telescope to perform more detailed observations for G339 and G45. Both projects are approved and assigned with top rank priority. However, the observation is delayed to 2021 due to the pandemic.

Research Products

• [Journal Article] Salt, Hot Water, and Silicon Compounds Tracing Massive Twin Disks (2020)
  • Author(s): Kei E. I. Tanaka, Yichen Zhang, Tomoya Hirota, Nami Sakai, Kazuhito Motogi, Kengo Tomida, Jonathan C. Tan, Viviana Rosero, Aya E. Higuchi, Satoshi Ohashi, Mengyao Liu, Koichiro Sugiyama
  • Journal Title: The Astrophysical Journal Letters Volume: 900 Pages: L2
  • DOI: 10.3847/2041-8213/abadfc
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The SOFIA Massive (SOMA) Star Formation Survey. III. From Intermediate- to High-mass Protostars (2020)
  • Author(s): Mengyao Liu, Jonathan C. Tan, James M. De Buizer, Yichen Zhang, Emily Moser, Maria T. Beltran, Jan E. Staff, Kei E. I. Tanaka, Barbara Whitney, Viviana Rosero, Yao-Lun Yang, Ruben Fedriani
  • Journal Title: The Astrophysical Journal Volume: 904 Pages: 75
  • DOI: 10.3847/1538-4357/abbefb
  • Peer Reviewed / Int'l Joint Research
• [Presentation] ALMA 1.3mm observations of massive star forming region G35.2-0.74 (2021)
  • Author(s): Yichen Zhang, Eva Greco, Yao-Lun Yang, Jonathan Tan, Kei Tanaka, James De Buizer, Ruben Fedriani, Mengyao Liu, Maite Beltran
  • Organizer: 237th Meeting of the American Astronomical Society
  • Int'l Joint Research
• [Presentation] Salt, Hot Water, and Silicon Compounds Tracing Massive Twin Disks (2021)
  • Author(s): Yichen Zhang, Kei E. I. Tanaka, Tomoya Hirota, Nami Sakai, Kazuhito Motogi, Kengo Tomida, Jonathan C. Tan, Viviana Rosero, Aya E. Higuchi, Satoshi Ohashi, Mengyao Liu, Koichiro Sugiyama
  • Organizer: 2021 Spring Annual Meeting of Astronomical Society of Japan
• [Presentation] ALMA View of the Innermost Regions of Massive Star Formation (2020)
  • Author(s): Yichen Zhang, Kei Tanaka, Jonathan Tan, Nami Sakai, Viviana Rosero, James De Buizer, Mengyao Liu, Diego Mardones, Maria Beltran, Kaitlin Kratter, Diego Mardones, Guido Garay
  • Organizer: 大質量星形成ワークショップ2020