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Title
On the Origin of Star Formation Quenching of Galaxies in Group Environments Using the NewHorizon Simulation
KIAS Author
Pichon, Christophe
Journal
ASTROPHYSICAL JOURNAL, 2024
Archive
Abstract
We study star formation (SF) quenching of satellite galaxies with M-* > 10(7)M(circle dot) within two low-mass groups (M-vir = 10(12.9) and 10(12.7)M(circle dot)) using the NewHorizon simulation. We confirm that satellite galaxies (M-* less than or similar to 10(10)M(circle dot)) are more prone to quenching than their field counterparts. This quenched fraction decreases with increasing stellar mass, consistent with recent studies. Similar to the findings in cluster environments, we note a correlation between the orbital motions of galaxies within these groups and the phenomenon of SF quenching. Specifically, SF is suppressed at the group center, and for galaxies with M-* > 10(9.1)M(circle dot), there is often a notable rejuvenation phase following a temporary quenching period. The SF quenching at the group center is primarily driven by changes in SF efficiency and the amount of gas available, both of which are influenced by hydrodynamic interactions between the interstellar medium and surrounding hot gas within the group. Conversely, satellite galaxies with M-* < 10(8.2)M(circle dot) experience significant gas removal within the group, leading to SF quenching. Our analysis highlights the complexity of SF quenching in satellite galaxies in group environments, which involves an intricate competition between the efficiency of SF (which depends on the dynamical state of the gas) on the one hand, and the availability of cold dense gas on the other hand. This challenges the typical understanding of environmental effects based on gas stripping through ram pressure, suggesting a need for a new description of galaxy evolution under mild environmental effects.