Boylan-Kolchin Michael
Department of Astronomy, The University of Texas at Austin, Austin, TX USA.
Nat Astron. 2023;7(6):731-735. doi: 10.1038/s41550-023-01937-7. Epub 2023 Apr 13.
Early data from the James Webb Space Telescope (JWST) have revealed a bevy of high-redshift galaxy candidates with unexpectedly high stellar masses. An immediate concern is the consistency of these candidates with galaxy formation in the standard CDM cosmological model, wherein the stellar mass () of a galaxy is limited by the available baryonic reservoir of its host dark matter halo. The mass function of dark matter haloes therefore imposes an absolute upper limit on the number density (>, ) and stellar mass density (>, ) of galaxies more massive than at any epoch . Here I show that the most massive galaxy candidates in JWST observations at ≈ 7-10 lie at the very edge of these limits, indicating an important unresolved issue with the properties of galaxies derived from the observations, how galaxies form at early times in CDM or within this standard cosmology itself.
詹姆斯·韦布空间望远镜（JWST）的早期数据揭示了大量具有意外高恒星质量的高红移星系候选体。一个直接的问题是，这些候选体与标准冷暗物质（CDM）宇宙学模型中的星系形成是否一致，在该模型中，星系的恒星质量（）受到其宿主暗物质晕中可用重子物质储量的限制。因此，暗物质晕的质量函数对任何时期质量大于的星系的数密度（>，）和恒星质量密度（>，）施加了一个绝对上限。在这里，我表明，JWST在≈7 - 10观测到的质量最大的星系候选体正处于这些极限的边缘，这表明从观测中得出的星系属性存在一个重要的未解决问题，即星系在CDM中或在这个标准宇宙学本身中如何在早期形成。
