Accretion onto Stars in the Disks of Active Galactic Nuclei

Disks of gas accreting onto supermassive black holes are thought to power active galactic nuclei (AGN). Stars may form in gravitationally unstable regions of these disks, or may be captured from nuclear star clusters. Because of the dense gas environment, the evolution of these embedded stars can diverge dramatically from those in the interstellar medium. This work extends previous studies of stellar evolution in AGN disks by exploring a variety of ways in which accretion onto stars in AGN disks may differ from Bondi accretion. We find that tidal effects from the supermassive black hole significantly alter the evolution of stars in AGN disks, and that our results do not depend critically on assumptions about radiative feedback on the accretion stream. Thus, in addition to depending on the ambient density and sound speed, the fate of stars in AGN disks depends sensitively on the distance to and mass of the supermassive black hole. This affects the location in the disk in which stellar explosions occur, where compact remnants form and potentially merge to produce gravitational waves, and where different types of chemical enrichment take place.

Automated summary

Research indicates that stars formed in accretion disks around supermassive black holes exhibit significant differences in evolution compared to those in the interstellar medium, depending largely on the mass and distance of the black hole. Tidal effects from the black hole greatly impact the evolution of stars in AGN disks. The location of stellar explosions, formation of compact remnants, potential mergers producing gravitational waves, and different types of chemical enrichment in AGN disks are sensitive to the environmental conditions and parameters of the supermassive black hole.