Speaker
Description
Modeling the winds and jets that expel baryons from collapsed structures represents the major strength and greatest weakness of our current galaxy formation and evolution paradigm. While nearly all models can reproduce many observables, they diverge significantly in predicting the amount and distribution of baryonic mass in common galaxy groups.
In particular, different AGN feedback implementations can lead to vastly different outcomes, ranging from excessively hot, gas-rich groups to systems entirely devoid of gas. Moreover, key observational questions remain about when, where, and how much AGN energy is distributed into their environments. Therefore, having observational constraints on the baryonic content of groups, in terms of both hot gas and galaxy populations, is crucial for accurately modeling large-scale structures and galaxy evolution.
The new eROSITA All Sky Survey (eRASS) will provide unprecedented statistics on sources in the group regime due to the large area surveyed. Nevertheless, it will not capture the bulk of the group population due to relatively short exposure times. I will demonstrate that the stacking analysis of optically selected groups is highly effective in recovering the average X-ray properties of the bulk of the group population. This approach provides a comprehensive picture of the gas content in galaxy groups down to the scale of Milky Way-sized halos.
