EA: Formation of Ultra-Diffuse galaxies in different environments – Benavides

Being the lowest-surface-brightness galaxies known, Ultra-diffuse galaxies (UDGs) are among the most intriguing objects in the Universe. Since their rediscovery a few years ago, different mechanisms have been proposed to explain the formation of these puzzling objects with the stellar mass of a dwarf galaxy but the size of a large galaxy like the Milky Way. Using cosmological numerical simulations we identify and follow simulated UDGs galaxies to analyze their formation mechanism and temporal evolution focusing on environmental dependencies. As envisioned by simple analytical arguments, we find that these extended objects form preferentially in dark matter halos having systematically higher angular momentum. For satellite galaxies, in high-density environments, we found that although tidal interactions are correlated to size increase it is not necessarily an effective mechanism.