Cosmology 2025 @ Elba Island

The Host Masses of Active Galactic Nuclei before Cosmic Noon with TNG-Cluster and other cosmological Simulations of Galaxies

12 Sept 2025, 09:50

40m

Hermitage Hotel, Isola D'Elba

Talk The Evolving Universe (Reionization, first galaxies and their SMBH, Quasars and AGN, the assembly of cosmological structures) Morning session 5

Speaker

Akanksha Kapahtia (Max Planck Institute for Astronomy Heidelberg)

Description

We investigate the host dark matter halo masses of AGNs across various cosmological simulations of galaxies (Illustris, IllustrisTNG, TNG-Cluster, Simba and EAGLEs). In particular we examine the co-evolution of the luminosity of AGNs in relation to the mass of their host dark matter halo from z=7 to z=3. Despite differences in AGN feedback implementations and SMBH seeding prescriptions across simulations, we find that AGNs of a given luminosity can occupy a wide range of halo masses, exhibiting a significant scatter. We also find that in the TNG model, the median halo mass of "quasars" remains roughly constant with redshift which is consistent with quasar clustering measurements, implying that luminous quasars do not exclusively occupy the most massive halos, which increasingly host supermassive black holes depleted of their gas reserves near cosmic noon.