The star capture model for fueling quasar accretion disks

TL;DR

This paper develops a detailed model for how stars from outside the accretion disk can be captured by the disk, fueling quasar activity, by analyzing the effects of perturbations on stellar orbits near black holes.

Contribution

It provides the first detailed calculations of star capture from distant regions near black holes, considering perturbations that bring stars into the accretion disk.

Findings

Perturbing masses influence stellar trajectories towards the disk.

Stars from far regions can be captured and contribute to quasar fueling.

The model enhances understanding of star-disk interactions in galactic centers.

Abstract

Although the powering mechanism for quasars is now widely recognized to be the accretion of matter in a geometrically thin disk, the transport of matter to the inner region of the disk where luminosity is emitted remains an unsolved question. Miralda-Escud\'e & Kollmeier (2005) proposed a model whereby quasars are fuelled when stars are captured by the accretion disk as they plunge through the gas. Such plunging stars can then be destroyed and deliver their mass to the accretion disk. Here we present the first detailed calculations for the capture of stars originating far from the accretion disk near the zone of influence of the central black hole. In particular we examine the effect of adding a perturbing mass to a fixed stellar cusp potential on bringing stars into the accretion disk where they can be captured. The work presented here will be discussed in detail in an upcoming publication Kennedy et al. (2010).