Project A
Assessing Assembly Bias Through the Satellite Populations of X-ray–Selected Halos
Ilaria Marini (ESO), Victoria Toptun (ESO), Natanael de Isídio (ESO)
Galaxy groups and clusters are key environments for studying how galaxies evolve, because satellite galaxies in these systems experience a range of physical processes—such as gas stripping, starvation, and tidal interactions—that depend strongly on their surroundings. A useful way to characterize these environments is through their X-ray luminosity (Lx), which reflects the amount and density of hot gas in the system. Since Lx is linked not only to halo mass but also to a system’s formation history and the density of the surrounding large-scale structure, it may serve as a broader indicator of environmental conditions and possible assembly bias.
This project will investigate how the properties of satellite galaxies—such as colors, star-formation activity, stellar masses, and simple morphology indicators—vary across groups and clusters with different X-ray luminosities. By combining X-ray–selected systems with optical galaxy data, and by using either observational datasets and/or cosmological simulations, the study will test whether Lx provides information about galaxy evolution that goes beyond what halo mass alone can account for.
