重子印记对暗物质晕的影响：利用CAMELS刻画浓度-质量完整概率分布

中文摘要 AI 辅助

晕浓度表征了晕内物质的分布，是模拟从兆秒差距到亚千秒差距尺度上物质分布的重要工具。尽管在连接天体物理学对平均浓度（作为晕质量的函数）的影响方面已取得显著进展，但同样的连接对浓度分布高阶矩的影响仍远未得到充分探索。我们利用CAMELS模拟套件中的IllustrisTNG运行，同时量化天体物理学和宇宙学对浓度-质量关系前四阶矩（均值、离散度、偏度和峰度）的依赖性。我们使用归一化流来模拟浓度分布，作为晕质量、红移以及六个宇宙学/天体物理学参数的函数。我们关注的质量范围为$M_{\rm vir} \in [10^{11}, 10^{14.5}] M_{\odot}/h$，红移范围为$z \in [0, 1]$。所有高阶矩都表现出对天体物理学和宇宙学的质量依赖性敏感性。在仅含暗物质的模拟中，其行为遵循已知的活跃并合效应以及较小晕中的潮汐剥离效应。一旦包含星系形成，离散度在银河系（MW）质量尺度上表现出非单调行为，且该行为的幅度强烈受重子分数和超新星（SNe）反馈参数的影响。偏度对重子分数也有较大敏感性，而对其他参数大多不敏感，而峰度则遵循偏度设定的行为。ASTRID模拟套件的结果显示出与IllustrisTNG相似的行为。这些高阶矩的宇宙学和天体物理学依赖性影响了那些对浓度-质量关系完整分布敏感的分析，特别是对于处于或低于银河系质量尺度的晕。

英文摘要

The halo concentration, which represents the distribution of matter within a halo, is a vital tool for modeling the matter distribution on scales ranging from megaparsecs to sub-kiloparsecs. While significant progress has been made on connecting the impact of astrophysics on the mean concentration as a function of halo mass, the same connection to higher moments of the concentration distribution remains far less explored. We employ the IllustrisTNG runs in the CAMELS simulation suite to simultaneously quantify the astrophysics and cosmology dependence of the first four moments of the concentration-mass relation; the mean, the scatter, the skewness, and the kurtosis. We use normalizing flows to model the concentration distribution as a function of halo mass, redshift, and six cosmological/astrophysical parameters. We focus on the mass range $M_{\rm vir} \in [10^{11}, 10^{14.5}] M_{\odot}/h$, and the redshift range $z \in [0, 1]$. All higher-order moments exhibit a mass-dependent sensitivity to both astrophysics and cosmology. The behavior in dark matter-only simulations follows the known effects of active mergers and of tidal stripping in smaller halos. Once galaxy formation is included, the scatter shows non-monotonic behavior at the Milky Way (MW) mass-scale, and the amplitude of this behavior is strongly influenced by the baryon fraction and supernovae (SNe) feedback parameters. The skewness has a large sensitivity to the baryon fraction as well and is mostly insensitive to the other parameters, while the kurtosis follows the behavior set by the skewness. Results for the ASTRID simulation suite show similar behavior as that of IllustrisTNG. The cosmology and astrophysics dependence of these higher-order moments impact analyses that are sensitive to the full distribution of the concentration-mass relation, particularly for halos at/below the MW mass scale.

发表机构

• University of Chicago（芝加哥大学）
• Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙物理学研究所）

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