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arXiv 2402.14218astro-ph.GA
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IllustrisTNG中宁静星系的 velocity dispersions

Velocity Dispersions of Quiescent Galaxies in IllustirisTNG

Jubee Sohn, Margaret J. Geller, Josh Borrow, Mark Vogelsberger

AI总结:

本文利用IllustrisTNG模拟研究宁静星系中心恒星速度弥散,验证其受粒子识别、视线方向、计算方法和分辨率影响很小,并发现模拟在固定恒星质量下低估观测速度弥散,同时证明该量可约束暗物质子晕质量。

摘要:

我们基于IllustrisTNG宇宙学流体力学模拟,考察了子晕的中心恒星速度弥散。中心速度弥散是连接星系与其暗物质子晕的基本可观测量。我们仔细探索了用不同定义推导出的模拟恒星速度弥散,以评估可能的系统误差。我们探讨了成员恒星粒子识别方式、观测视线方向、速度弥散计算技术以及模拟分辨率变化所带来的影响。这些问题均未对速度弥散产生显著影响;任何系统不确定性都小于随机误差。我们将恒星质量-速度弥散关系作为对模拟的观测检验。在固定恒星质量下,观测到的速度弥散显著超过模拟结果。这一差异是IllustrisTNG模拟的一个有价值的基准,因为模拟并未被显式调参以匹配该关系。我们证明,恒星速度弥散提供了暗物质速度弥散和暗物质子晕质量的度量。

英文摘要:

We examine the central stellar velocity dispersion of subhalos based on IllustrisTNG cosmological hydrodynamic simulations. The central velocity dispersion is a fundamental observable that links galaxies with their dark matter subhalos. We carefully explore simulated stellar velocity dispersions derived with different definitions to assess possible systematics. We explore the impact of variation in the identification of member stellar particles, the viewing axes, the velocity dispersion computation technique, and simulation resolution. None of these issues impact the velocity dispersion significantly; any systematic uncertainties are smaller than the random error. We examine the stellar mass-velocity dispersion relation as an observational test of the simulations. At fixed stellar mass, the observed velocity dispersions significantly exceed the simulation results. This discrepancy is an interesting benchmark for the IllustrisTNG simulations because the simulations are not explicitly tuned to match this relation. We demonstrate that the stellar velocity dispersion provides measures of the dark matter velocity dispersion and the dark matter subhalo mass.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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