Centre de Recherche Astrophysique de Lyon

Séminaire Arif Babul (U Vancouver)

Mai 14, 2024 | Séminaires

The Formation and Evolution Massive Galaxies in the Cosmos and their Circumgalactic Environment.

Tuesday 14 May 2024

Title : The Formation and Evolution Massive Galaxies in the Cosmos and their Circumgalactic Environment

Speaker : Arif Babul (University of Victoria)

Abstract :


Contrary to many stereotypes about massive galaxies, the observed systems are diverse in their star formation rates, kinematic properties, and morphologies. Studying how they evolve into and express such diverse characteristics is an important piece of the galaxy formation puzzle. Here, we focus on a subset of massive galaxies, the brightest group galaxies (BGGs). We use a high-resolution cosmological suite of simulations using the Romulus galaxy formation model, and compare simulated central galaxies in group-scale halos at z=0 to their observed counterparts. Since most galaxy formation models are calibrated using measures that are strongly influenced by the properties and evolution of “normal” Milky-Way like galaxies, this exercise is also an opportunity to test the limits of these models. The comparison encompasses the stellar mass-halo mass relation, various kinematic properties and scaling relations, morphologies, and the star formation rates. We find Romulus BGGs that are early-type S0 and elliptical galaxies as well as late-type disk galaxies ; we find BGGs that are fast-rotators as well as slow-rotators ; and we observe BGGs transforming from late-type to early-type following strong dynamical interactions with satellites.