Gas Evolution Of Satellite Galaxies

Observations of HI in a variety of environments in local group have found that the HI fraction in galaxies depends on environment.Late-type galaxies in clusters have lower HI content than field galaxies of the same morphology,size,and optical luminosity.This study will use the semi-analytic model GAEA-RPS to study the dependence of HI fraction on environment.We divide galaxies by their stellar mass into two groups and compare with observational results of ALFALFA,respectively.For both samples,the HI fraction decreases with increasing environment density,which is consistent with ALFALFA.The same trend is found for central and satellite galaxies from GAEA-RPS,though the model only exerts environmental effects on the satellite galaxies.The frmHI of the central galaxies decreases with the increase in the environmental density because of the pre-prossing effect.Satellite galaxies fall in halo with higher densities earlier,are affected by the environment for a longer period of time,and lose more gas fractions.We also study the influence of the five physical mechanisms involved in the model that affect the gas fractions of satellite galaxies,and find that star formation process consumes most of cold gas after satellite's infall,for both massive and low-mass galaxies.The ram pressure stripping only contributes 1%of the cold gas consumption.Galaxies that fell before redshift z?1 still have a large fraction of gas cooling.Whereas those fell after z<1 are mostly replenished by recycling.