Abstract

Contributed Talk - Splinter GalaxyClusters

Wednesday, 09 September 2026, 15:15   (MW-1050)

How the large-scale environment impacts galaxy groups

Ilaria Marini
ESO / LMU

Mapping the distribution of baryonic mass in our Universe down to the group-sized halo masses, it is essential to clarify how much of the missing baryons are locked up in halos and in filaments. Non-gravitational processes affect the baryonic content of groups and clusters of galaxies, causing deviations from the theoretical self-similar expectations. Indeed, many observational studies advocate the presence of feedback (such as the one provided by black holes residing in central galaxies) to explain their findings on the hot gas and overall baryonic content. At the same time, the large-scale environment can play a significant role in fuelling and recycling baryons within halos. Combined X-ray and optical data can allow us to investigate these features down to group scales, thanks to the unprecedented sensitivity reached by state-of-the-art telescopes in X-ray (i.e. eROSITA) and spectroscopic optical surveys such as SDSS, GAMA and WEAVES. In order to provide a fair comparison and be able to address the possible observational biases, we reconstruct a large lightcone from the set of cosmological hydrodynamical simulations, Magneticum. We mimic the observational conditions and generate synthetic datasets that closely resemble the observations of galaxies in cluster/group-size halos. We present the results of this analysis, highlighting the selection effects that are present in these surveys and the expectations on the large-scale environment in which detected galaxy groups reside.