Unveiling the metal-enriched circumgalactic and intragroup medium in emission at z~1 with MUSE

Using the exquisite MUSE eXtremely Deep Field data, we report the discovery of a 1000 proper kpc^2 MgII emission nebula (above a 2σ significance level), providing the first panoramic view of the spatial distribution of magnesium in the intragroup medium of a low mass group of five star-forming galaxies at z=1.31 (Leclercq et al. 2023). The galaxy group members are separated by less than 50 physical kpc in projection and ≈120 km/s in velocity space. The most massive galaxy has a stellar mass of 10^9.35 Msol and shows an MgII P-Cygni line profile indicating the presence of an outflow. The detected MgII nebula has a maximal projected extent of ≈70 kpc including a low surface brightness gaseous bridge between two subgroups of galaxies. Our MUSE data also reveal extended FeII* and [OII] emission in the vicinity of the most massive galaxy. Our results suggest that both tidal stripping effects from galaxy interactions and outflows are enriching the intragroup medium of this low mass and high redshift system. In this talk, I will present this recent paper, along with some preliminary results from our ongoing statistical study of the Mg II halos in the MUSE datacubes.