Study of stellar objects embedded in AGN accretion disks around massive Black Holes have been motivated by i) the disk of stars that formed in-situ in the galactic center; ii) the redshift independence of metallicity in AGN disks, which also suggest in-situ pollution; iii) massive LIGO-Virgo gravitational wave sources that possibly evolved in a gas rich environment, and iv) quasi-periodic eruptions connected to star-disk collisions.
In this talk, I will introduce some recent progress on star formation and capture in AGN disks, as well as structure and lifetime of embedded massive stars and their co-evolution with the chemical abundance of AGN disks. In relation to the AGN channel for LIGO-Virgo events, I will discuss how tidal interaction in hierarchical systems influences the accretion, migration and mutual interaction of disk-embedded compact objects, and therefore their merger properties. I will emphasize that with the environment of AGN disks (featuring strong turbulence, radiation pressure prevalence, dynamical crowded population of stellar mass objects) being much more extreme than protoplanetary disks, established theories from planet formation must be transplanted into the AGN context with caution.
Yi-Xian Chen is a PhD candidate at the Department of Astrophysical Sciences, Princeton University, who obtained his BS in Physics at Tsinghua University in 2021. His research interests include planet formation and evolution, protoplanetary disks, and applying frameworks of planet-disk interaction to study properties of stellar objects embedded in AGN disks. His current focus is on using radiation hydrodynamic simulations to study the evolution of massive stars in AGN disks, and how their thermal feedback influences the AGN disk.