The thesan project: Lyman-α emitter luminosity function calibration
The thesan project: Lyman-α emitter luminosity function calibration
复制标题
论文项目：Lyman-α发射器光度函数校准
DOI：
10.1093/mnras/stad789
复制
发表时间：
2023
影响因子：
4.8
通讯作者：
Hernquist, Lars
中科院分区：
文献类型：
--
作者：
Xu, Clara;Smith, Aaron;Borrow, Josh;Garaldi, Enrico;Kannan, Rahul;Vogelsberger, Mark;Pakmor, Rüdiger;Springel, Volker;Hernquist, Lars
再电离时期 Lyα 发射星系（LAE）的可观测性可以为不断演变的中性氢气分布提供灵敏的探测，从而为区分不同的再电离模型设置有价值的约束。在这项研究中，我们利用新的大容量宇宙辐射-流体动力学模拟套件来直接模拟单个星系的 Lyα 发射以及随后通过星系际介质的传输。thesan 将区域辐射-流体动力学求解器与 IllustrisTNG 星系形成模型相结合，包括高分辨率和中分辨率模拟，旨在研究晕质量相关的逃逸分数、替代暗物质模型和数值收敛的影响。我们发现基于再电离历史、气泡形态、线中心频率偏移和星系亮度的 Lyα 传输存在重要差异。对于给定的全局中性分数，当低质量晕主导再电离而不是高质量晕时，Lyα 传输会减少。此外，单个星系的视线变化大于所有星系的变化。这共同影响 LAE 的可见度，直接影响观测到的 Lyα 光度函数 (LF)。我们使用 SWIFTE 模拟器进行高斯过程回归，快速约束灰尘逃逸分数和出现的谱线轮廓的经验模型，以匹配观察到的 LF。我们发现尘埃强烈影响Lyα传输和覆盖MUV≲ -19星系在晕中的部分，使得非LAE中去除Lyα光子的主要模式从低IGM传输转变为z∼7附近的高尘埃吸收。
The observability of Lyα emitting galaxies (LAEs) during the Epoch of Reionization can provide a sensitive probe of the evolving neutral hydrogen gas distribution, thus setting valuable constraints to distinguish different reionization models. In this study, we utilize the newthesansuite of large-volume () cosmological radiation-hydrodynamic simulations to directly model the Lyα emission from individual galaxies and the subsequent transmission through the intergalactic medium.thesancombines thearepo-rtradiation-hydrodynamic solver with the IllustrisTNG galaxy formation model and includes high- and medium-resolution simulations designed to investigate the impacts of halo-mass-dependent escape fractions, alternative dark matter models, and numerical convergence. We find important differences in the Lyα transmission based on reionization history, bubble morphology, frequency offset from line centre, and galaxy brightness. For a given global neutral fraction, Lyα transmission reduces when low-mass haloes dominate reionization over high-mass haloes. Furthermore, the variation across sightlines for a single galaxy is greater than the variation across all galaxies. This collectively affects the visibility of LAEs, directly impacting observed Lyα luminosity functions (LFs). We employ Gaussian Process Regression usingSWIFTEmulatorto rapidly constrain an empirical model for dust escape fractions and emergent spectral-line profiles to match observed LFs. We find that dust strongly impacts the Lyα transmission and covering fractions ofMUV≲ −19 galaxies inhaloes, such that the dominant mode of removing Lyα photons in non-LAEs changes from low-IGM transmission to high dust absorption aroundz∼ 7.