Abstract Details

Name: Anirban Chowdhary
Affiliation: Presidency University
Conference ID : ASI2024_391
Title : Halo Occupation Distribution of Quasars : Redshift Evolution and Effects of AGN feedback
Authors : AnirbanChowdhary1, DweepsaDas1, SuchetanaChatterjee1
Authors Affiliation: 1 Presidency University, Kolkata-700073, India
Mode of Presentation: Poster
Abstract Category : Galaxies and Cosmology
Abstract : The Halo Occupation Distribution (HOD) has been used as a powerful tool in interpreting quasar clustering and the quasar-halo connection. The HOD formalism provides a complete knowledge of the host halo mass distributions of quasars over a range of redshifts. While extracting host halo distributions of quasar and Active Galactic Nuclei(AGN) from clustering studies, the HOD is assumed to be weakly dependent on redshift. Without any theoretical study of redshift evolution of the HOD, this assumption poses a challenge for studies with quasar clustering and studies of stacked signals from quasars. We use SIMBA and IllustrisTNG suite of cosmological simulations to probe the HOD of the high end of the AGN luminosity function and characterise their redshift evolution. We find that owing to different models of subgrid AGN-physics, TNG and SIMBA produce different HOD of quasars. In both simulations, we find that the highest luminosity quasars have a significant redshift evolution in both simulations. SIMBA produces a stronger redshift evolution for lower luminosity AGNs as compared to TNG. We also compare the two-point correlation function and the conditional luminosity functions of luminous AGNs in the two simulations. We use the smaller volume SIMBA simulation with various AGN feedback modes to study the effect of AGN feedback on the clustering of AGNs and their broad Host Halo Distributions. We find that the Jet mode of feedback is the dominant mechanism for the redshift evolution of the AGN HOD.