Event type
Event date
Venue
Sala Sousa Pinto and Teams
Speaker
Razieh Ranjbar (Institute for Research in Fundamental Sciences, Iran)
Event Website
The most massive black holes (BHs) reside at the centers of galaxies and grow through accretion, appearing as active galactic nuclei (AGN). AGN and their host galaxies have been studied in great detail, but we still know little about how the surrounding dark matter (DM) halo affects BH growth. We study quasi-spherical accretion onto BHs embedded in DM halos to understand how the DM environment influences the growth and coevolution of central supermassive BHs. We add DM halos (Hernquist, NFW) to general relativistic hydrodynamics (GRHD) simulations and follow how they affect the structure of the accretion flow, from the Bondi radius down to the event horizon. Using both 1D and 2.5D simulations of quasi-spherical accretion, we show that the gravity of DM can significantly change the structure and dynamics of the flow. We also study the effects of the stellar and DM components of galaxies with semi-analytical models of slowly rotating accretion flows in the Newtonian framework. Our current research investigates dense DM distributions, including bosonic DM, and their effects on accretion flows around hairy Kerr BHs. We aim to predict observable signatures of these distributions from how they change the accretion flow, which would shed light on the link between BH growth, DM, and galaxy evolution. Our results connect BH astrophysics to fundamental physics and may help the next-generation Event Horizon Telescope (ngEHT) search for signatures of these phenomena.