ヒラノ シンゴ   Hirano Shingo
  平野 信吾
   所属   神奈川大学  工学部 応用物理学科
   職種   助教
言語種別 英語
発行・発表の年月 2024/04
形態種別 学術雑誌
査読 査読あり
標題 Low-mass Population III Star Formation due to the HD Cooling Induced by Weak Lyman-Werner Radiation
執筆形態 共著
掲載誌名 The Astrophysical Journal
掲載区分国外
出版社・発行元 American Astronomical Society
巻・号・頁 965(2),pp.141-151
担当区分 責任著者
著者・共著者 ◎Sho Nishijima, Shingo Hirano,Hideyuki Umeda
概要 We investigate the effects of LW radiation at 18 different intensities, ranging from JLW/J21 = 0 (no radiation) to 30 (H-cooling cloud), on the primordial star-forming gas cloud obtained from a three-dimensional cosmological simulation. Due to the HD cooling, however, the dependence of gas cloud temperature on JLW deviates from the aforementioned increasing trend for a specific range of intensities (JLW/J21 = 0.025-0.09). In HD-cooling clouds, the temperature remained below 200 K during 105 yr after the first formation of the high-density region, maintaining a low accretion rate. Finally, the HD-cooling clouds have only a low-mass dense core (above 108 cm−3) with about 1-16 Msun, inside of which a low-mass Pop III star with < 0.8 Msun (a so-called "surviving star") could form. The upper limit of star formation efficiency significantly decreases as HD cooling becomes effective.