The environmental effect is commonly used to explain the excess of gas-poor galaxies in galaxy clusters. Meanwhile, the presence of gas-poor galaxies at cluster outskirts, where galaxies have not spent enough time to feel the cluster environmental effect, hints for the presence of pre-processing. Using cosmological hydrodynamic simulations on 16 clusters, we investigate the mechanisms of gas depletion of galaxies found inside clusters. The gas depletion mechanisms can be categorized into three channels based on where and when they took place. First, 34$\%$ of our galaxies are gas poor before entering clusters (`pre-processing'). They are mainly satellites that have undergone the environmental effect inside group halos. Second, 43$\%$ of the sample became quickly gas deficient in clusters before the first pericentric pass (`fast cluster processing'). Some of them were group satellites that are low in gas at the time of cluster entry compared to the galaxies directly coming from the field. Even the galaxies with large gas fractions take this channel if they fall into massive clusters ($> 10^{14.5}\, \rm M_{\odot}$) or approach cluster centers through radial orbits. Third, 24$\%$ of our sample retain gas even after their first pericentric pass (`slow cluster processing') as they fall into the less massive clusters and/or have circular orbits. The relative importance of each channel varies with a cluster's mass, while the exact degree of significance is subject to large uncertainties. Group pre-processing accounts for a third of the total gas depletion; but it also determines the gas fraction of galaxies at their cluster entry which in turn determines whether a galaxy should take the fast or the slow cluster processing.
A New Metal-poor Globular Cluster and Resolved Stars in the Outer Disk of the Black Eye Galaxy M64: Implication for the Origin of the Type III Disk Break
M3DIS -- A grid of 3D radiation-hydrodynamics stellar atmosphere models for stellar surveys. II. Carbon-enhanced metal-poor stars
Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔学院、尼尔斯·玻尔研究所）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森尼天体物理中心）；Radcliffe Institute for Advanced Studies at Harvard University（哈佛大学拉德克利夫高等研究院）
Non-equilibrium chemistry and radiation hydrodynamics in metal-poor and metal-rich interstellar gas
Center for Computational Astrophysics, Flatiron Institute（平顿研究所计算天体物理中心）；Department of Physics and Astronomy, Rutgers University（罗格斯大学物理与天文系）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Max-Planck-Institut für Extraterrestrische Physik（马克斯·普朗克地外物理学研究所）
A Multiwavelength Assessment Disfavoring the X-ray Binary Origin of He III Regions in Metal-Poor Star-Forming Dwarf Galaxies
University of Nevada, Reno（内华达大学雷诺分校）；Nevada Center for Astrophysics（内华达天体物理中心）；INAF - Osservatorio Astrofisico di Torino（意大利国家天体物理研究所都天文台）；The University of Sydney（悉尼大学）；Greenhill Observatory（格林希尔天文台）；University of Michigan（密歇根大学）；Université de Strasbourg（斯特拉斯堡大学）；Catholic University of America（美国天主教大学）
