分类: 天文学 >> 天文学 提交时间: 2024-05-10 合作期刊: 《Research in Astronomy and Astrophysics》
摘要: The overabundance of the red and massive candidate galaxies observed by the James Webb Space Telescope (JWST) implies efficient structure formation or large star formation efficiency at high redshift z ∼ 10. In the scenario of a low or moderate star formation efficiency, because massive neutrinos tend to suppress the growth of structure of the universe, the JWST observation tightens the upper bound of the neutrino masses. Assuming Λ cold dark matter cosmology and a star formation efficiency ∈[0.05, 0.3] (flat prior), we perform joint analyses of Planck+JWST and Planck+BAO+JWST, and obtain improved constraints ∑mν < 0.196 eV and ∑mν < 0.111 eV at 95% confidence level, respectively. Based on the above assumptions, the inverted mass ordering, which implies ∑mν ≥ 0.1eV, is excluded by Planck+BAO+JWST at 92.7% confidence level.
分类: 天文学 >> 天文学 提交时间: 2024-05-10 合作期刊: 《Research in Astronomy and Astrophysics》
摘要: We develop a Python tool to estimate the tail distribution of the number of dark matter halos beyond a mass threshold and in a given volume in a light-cone. The code is based on the extended Press–Schechter model and is computationally efficient, typically taking a few seconds on a personal laptop for a given set of cosmological parameters. The high efficiency of the code allows a quick estimation of the tension between cosmological models and the red candidate massive galaxies released by the James Webb Space Telescope, as well as scanning the theory space with the Markov Chain Monte Carlo method. As an example application, we use the tool to study the cosmological implication of the candidate galaxies presented in Labbé et al. The standard Λ cold dark matter (ΛCDM) model is well consistent with the data if the star formation efficiency can reach ∼0.3 at high redshift. For a low star formation efficiency ∼ 0.1, the ΛCDM model is disfavored at ∼2σ–3σ confidence level.