Probing X-ray Hot Intragroup Gas in RESOLVE and ECO Galaxy Groups

Analyses of the colors, morphologies, and gas fractions of galaxies suggest that the hot intragroup medium plays an important role in environmental quenching through removal of cold gas or failure to replenish it. To more directly probe the X-ray hot gas content of galaxy groups and its influence on cold atomic gas, we use X-ray stacking to combine archival ROSAT All-Sky Survey (RASS) imaging with the group catalogs from two highly complete, volume limited z=0 surveys (RESOLVE and ECO), which contain approximately 9,000 total galaxy groups down to halo mass M_h ~ 10¹¹ M_⊙. We explore the relationship between group evolution and intragroup hot gas by stacking custom-reprocessed RASS images based on group properties such as halo mass or large-scale environmental density. We also take advantage of RESOLVE’s uniquely comprehensive HI census, and ECO’s larger flux-limited HI census (including newly computed upper limits), to investigate the halo mass and environment dependence of the relationship between cold and hot gas in groups. This research has been supported by National Science Foundation grant AST-18114486.