Sabti Nashwan, Muñoz Julian B, Kamionkowski Marc
William H. Miller III Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA.
Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, Texas 78712, USA.
Phys Rev Lett. 2024 Feb 9;132(6):061002. doi: 10.1103/PhysRevLett.132.061002.
The early-science observations made by the James Webb Space Telescope (JWST) have revealed an excess of ultramassive galaxy candidates that appear to challenge the standard cosmological model (ΛCDM). Here, we argue that any modifications to ΛCDM that can produce such ultramassive galaxies in the early Universe would also affect the UV galaxy luminosity function (UV LF) inferred from the Hubble Space Telescope (HST). The UV LF covers the same redshifts (z≈7-10) and host-halo masses (M_{h}≈10^{10}-10^{12}M_{⊙}) as the JWST candidates, but tracks star-formation rate rather than stellar mass. We consider beyond-ΛCDM power-spectrum enhancements and show that any departure large enough to reproduce the abundance of ultramassive JWST candidates is in conflict with the HST data. Our analysis, therefore, severely disfavors a cosmological explanation for the JWST abundance problem. Looking ahead, we determine the maximum allowable stellar-mass function and provide projections for the high-z UV LF given our constraints on cosmology from current HST data.
詹姆斯·韦布空间望远镜（JWST）早期的科学观测揭示了大量超大质量星系候选体的存在，这似乎对标准宇宙学模型（ΛCDM）构成了挑战。在此，我们认为，对ΛCDM的任何修正，若能在早期宇宙中产生此类超大质量星系，也会影响从哈勃空间望远镜（HST）推断出的紫外星系光度函数（UV LF）。UV LF所涵盖的红移范围（z≈7 - 10）和宿主晕质量（M_h≈10^10 - 10^12 M⊙）与JWST候选体相同，但它追踪的是恒星形成率而非恒星质量。我们考虑了超越ΛCDM的功率谱增强情况，并表明任何足以重现JWST超大质量候选体丰度的偏离都与HST数据相冲突。因此，我们的分析强烈不支持对JWST丰度问题的宇宙学解释。展望未来，我们确定了最大允许恒星质量函数，并根据当前HST数据对宇宙学的限制，给出了高红移UV LF的预测。
