AI 中文总结
本研究利用Magneticum Pathfinder模拟，探究空洞环境对星系和暗晕的影响，发现空洞暗晕质量更小，恒星形成符合常规，核心密度是影响空洞暗晕群体的关键参数。
AI 中文摘要
引力坍缩与宇宙加速膨胀的共同作用，使得宇宙中低密度空洞的体积占比随宇宙时间不断增加。这些区域因低密度呈现出独特环境，表现为类似拥有修正宇宙学参数的“口袋宇宙”。由于星系的形成与演化强烈依赖环境，本研究旨在明确空洞如何改变暗晕和星系，与宇宙中的一般群体存在何种差异。研究采用流体动力学宇宙学模拟套件Magneticum Pathfinder，并引入一组空洞暗晕质量函数（VHMFs），该函数追踪以空洞中心距离为变量的暗晕群体。研究发现，空洞中的星系暗晕总体质量小于模拟体积中的一般暗晕；随着空洞变得更欠致密，空洞暗晕与场暗晕的差异随时间演化，但在宇宙黎明时期两者群体仍非常相似。进一步评估空洞的特定属性是否影响VHMFs，发现与空洞暗晕群体相关的唯一重要参数是核心密度，即欠致密强度的度量。为评估密度环境对星系演化的影响，研究调查空洞星系与场星系在恒星属性上是否存在差异，计算恒星质量函数、暗晕质量-恒星质量关系及恒星形成主序，均采用相同的以空洞为中心的球壳。结果显示，尽管空洞总体包含的恒星质量更少，但星系沿恒星质量-暗晕质量的分布与其他区域一致，这表明空洞区域的恒星形成过程“符合常规”，与近期观测结果一致。
英文摘要
The combination of gravitational collapse and an accelerating expansion of the Universe drive an increasing fraction of volume toward becoming low-density voids across cosmic time. These regions present a unique environment due to their low density, which leads to them behaving similarly to "pocket universes" with modified cosmological parameters. Since the formation and evolution of galaxies is strongly tied to the environment, we aim to discern how voids alter halos and galaxies compared to the general population in the universe. We use the hydrodynamical cosmological simulation suite Magneticum Pathfinder and introduce a set of void halo mass functions (VHMFs), which trace the halo population as a function of void-centric distance. We find galactic halos in voids to be overall less massive than in the general simulation volume. This discrepancy between void and field halos evolves with time as the voids grow more underdense, while the populations are still very similar at cosmic dawn. Expanding on this, we evaluate whether specific properties of the voids affect the VHMFs. We find the only relevant parameter for the void halo population to be the core density, a measure of the strength of underdensity. To assess the impact of the density environment on the evolution of galaxies, we investigate whether there are any distinctions between void and field galaxies with regard to stellar properties. We compute the stellar-mass function, halo mass-stellar mass relation, as well as the star-forming main sequence using the same void-centric shells. Although voids contain overall less stellar mass, the distribution of galaxies along the stellar mass-halo mass follows that of other regions. This implies that SF proceeded "conventionally" in void regions, in agreement with more recent observations.
Comments12 pages, 9 figures
