observational study of star-formation suppression in barred galaxies

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K03928
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: Kyoto University
• Principal Investigator: Ohta Kouji 京都大学, 理学研究科, 教授 (50221825)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 銀河 / 星形成 / 銀河進化

Outline of Final Research Achievements

Galaxies evolve by converting gas to stars. Thus, revealing condition for star formation is very important for the understanding of galaxy evolution. In barred galaxies, active star formation is seen in an arm region as well as a bar end. However, in a bar region star formation is not seen, i.e., star formation is suppressed in the bar region. In order to reveal cause(s) for the star formation suppression, we aimed to clarify conditions to suppress (or promote) star formation, using barred galaxies as a good laboratory. We found a fraction of diffuse molecular gas which does not contribute to star formation is large in the bar region, leading low star formation efficiency. We also found molecular cloud in bar region is less massive and a high velocity encounter between molecular clouds occurs, also leading to low star formation efficiency.

Free Research Field

銀河天文学

Academic Significance and Societal Importance of the Research Achievements

宇宙の構造やその中での天体の形成や進化を明らかにすることは、人類の世界観を構築し、その精神的バックボーンを形成するという意味で、極めて重要である。宇宙の主要構成要素である銀河の形成・進化を解明することはこのような観点から重要であると言える。本研究は、近傍宇宙に存在する銀河を実験室として、銀河における星形成がどのような条件で起こるのか・起こらないのかを明らかにすることで、銀河や星の形成・進化の解明に大きな一歩を加えており、その意義は高いものと考える。