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 2024/03
形態種別 学術雑誌
査読 査読あり
標題 Early Structure Formation from Primordial Density Fluctuations with a Blue, Tilted Power Spectrum: High-redshift Galaxies
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 963(1),pp.2-9
担当区分 筆頭著者,責任著者
著者・共著者 Shingo Hirano, Naoki Yoshida
概要 Recent observations by the James Webb Space Telescope (JWST) discovered unexpectedly abundant luminous galaxies at high redshift, posing possibly a severe challenge to popular galaxy formation models. We study early structure formation in a cosmological model with a blue, tilted power spectrum (BTPS). We run a set of cosmological N-body simulations and derive the abundance of dark matter halos and galaxies under simplified assumptions on star formation efficiency. The enhanced small-scale power allows rapid nonlinear structure formation at z > 7, and galaxies with stellar mass exceeding 1010Msun can be formed by z = 9. The BTPS model reproduces the observed stellar mass density at z = 7-9, and thus eases the claimed tension between galaxy formation theory and recent JWST observations. We conduct a systematic study by varying the slope of the small-scale power spectrum to derive constraints on the BTPS model from a set of observations of high-redshift galaxies.