Stellar Death and Compact Object mergers in Galactic nuclei

TYPEAstrophysics Seminar
Speaker:Evgeni Grishin
Affiliation:Monash University, Australia
Organizer:Shmuel Bialy
Date:25.09.2024
Time:14:30 - 15:30
Location:Lidow 620
Abstract:

Title: Stellar Death and Compact Object mergers in Galactic nuclei

 

Abstract: 

The dynamical and hydrodynamical evolution of stars and stellar remnants is greatly affected by the dense galactic nuclei (GN) environment. We explore the complex interplay of several physical processes that shape the properties, rates and environments of nuclear transients and black hole (BH) mergers and gravitational-wave (GW) events: We show how few-body dynamics shape the rate and properties of multiple stars, BH and NS dynamical evolution and mergers. We show how to distinguish different orbits with future GW detectors. We also propose a model for forming multiple stellar discs in the galactic centre from jetted tidal disruption events. For active galactic nuclei (AGN), we study how an accretion disc modifies the light curves of exploding supernovae and their relation to other nuclear transients. We also examine the gravitational torques in AGN discs that drive BH's radial migration. We find that thermal diffusion greatly alters the existence and nature of migration traps in AGN discs, which are believed to be responsible for massive hierarchical GW mergers. We find that GW mergers predominantly occur in low-luminosity AGNs. We use detailed recoil kicks and AGN models to study the efficiency of BH mergers for different generations.

 

Hagai Perets