Numerical modeling the mass feeding rates onto accretion-modified stars embedded within AGN disks

TL;DR

This study uses 3D numerical simulations to analyze how the structure and vorticity of AGN disks affect the mass feeding rates onto embedded stars, revealing the impact of disk shear and angular momentum.

Contribution

It introduces a new model linking mass feeding rates to the thermal mass and angular momentum of gas, considering the effects of disk shear and vorticity.

Findings

Disk shear reduces feeding rates significantly.

An approximate formula relates feeding rates to angular momentum and thermal mass.

Feedback effects of accreting stars on the disk are discussed.

Abstract

Accretion disks surrounding supermassive black holes can potentially form stars within the self-gravitating region. These stars undergo high accretion rates because of the dense environment of the active galactic nuclei (AGN) accretion disk. The vorticity of the AGN disk may influence the ultimate mass feeding rate toward the star. In our study, we simulate mass feeding rates onto stars at different AGN disk thicknesses through 3D numerical models to explore the relationship between feeding rates and the thermal mass of the star ($q_{\rm th}$), defined as the ratio of the star's Bondi radius to the AGN disk thickness. Our findings indicate that disk shearing with angular momentum can notably decrease the feeding rate, and we provide an approximate formula that links the feeding rate based on the angular momentum of the surrounding gas and the thermal mass $q_{\rm th}$. Lastly, we examine the potential feedback of the rapidly accreting stars on the AGN disk and their subsequent evolution.