The influence of the environmental history on quenching star formation in a Λ cold dark matter universe
The influence of the environmental history on quenching star formation in a Λ cold dark matter universe
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DOI：
10.1093/mnras/stu1609
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发表时间：
2014-07
影响因子：
4.8
通讯作者：
M. Hirschmann;G. Lucia;D. Wilman;Simone M. Weinmann;A. Iovino;O. Cucciati;S. Zibetti;'Alvaro Villalobos
中科院分区：
文献类型：
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作者：
M. Hirschmann;G. Lucia;D. Wilman;Simone M. Weinmann;A. Iovino;O. Cucciati;S. Zibetti;'Alvaro Villalobos
我们详细分析了环境和环境历史对当地宇宙中央星系和卫星星系中恒星形成的抑制的影响。我们利用将星系形成模型应用于千年模拟而获得的公开星系目录。除了晕质量之外，我们还考虑各种固定尺度内星系的局部密度。将我们的模型预测与观测数据（SDSS）进行比较，我们证明模型在几个方面未能重现观察到的静止星系分数的密度依赖性：对于所探索的大多数恒星质量范围和密度，模型无法重现观察到的中心和卫星的类似行为，它们稍微低估了中心的静止分数，并显着高估了卫星的静止分数。我们在模型中表明，静止中央星系的密度依赖性是由过去曾是卫星的一小部分“后溅”中央星系引起的（因此受到环境过程的影响）。转向卫星星系，其静止部分的密度依赖性反映了对特定质量的母晕内轨道运行时间的依赖，与晕质量和距晕中心的距离密切相关。与观测估计值的比较表明，低质量卫星星系的气体消耗时间尺度相对较长，约为 5 Gyr。淬灭时间尺度随着卫星恒星质量的增加而减小。总体而言，为了改进当前使用的星系形成模型，需要改变内部过程（恒星形成和反馈）和环境过程（例如，使它们依赖于动态摩擦时间尺度并防止气体重新吸积到后溅星系上）的建模。
We present a detailed analysis of the influence of the environment and of the environmental history on quenching star formation in central and satellite galaxies in the local Universe. We take advantage of publicly available galaxy catalogues obtained from applying a galaxy formation model to the Millennium simulation. In addition to halo mass, we consider the local density of galaxies within various fixed scales. Comparing our model predictions to observational data (SDSS), we demonstrate that the models are failing to reproduce the observed density dependence of the quiescent galaxy fraction in several aspects: for most of the stellar mass ranges and densities explored, models cannot reproduce the observed similar behaviour of centrals and satellites, they slightly under-estimate the quiescent fraction of centrals and significantly over-estimate that of satellites. We show that in the models, the density dependence of the quiescent central galaxies is caused by a fraction of "backsplash" centrals which have been satellites in the past (and were thus suffering from environmental processes). Turning to satellite galaxies, the density dependence of their quiescent fractions reflects a dependence on the time spent orbiting within a parent halo of a particular mass, correlating strongly with halo mass and distance from the halo centre. Comparisons with observational estimates suggest relatively long gas consumption time scales of roughly 5 Gyr in low mass satellite galaxies. The quenching time scales decrease with increasing satellite stellar mass. Overall, a change in modelling both internal processes (star formation and feedback) and environmental processes (e.g. making them dependent on dynamical friction time-scales and preventing the re-accretion of gas onto backsplash galaxies) is required for improving currently used galaxy formation models.