Accretion disk warping by resonant relaxation: The case of maser disk NGC4258

TL;DR

This paper proposes a novel mechanism for warping the maser disk in NGC 4258, attributing it to resonant torquing by surrounding stars, which can explain the observed disk warp.

Contribution

It introduces resonant torquing by stars as a new explanation for disk warping, expanding understanding beyond previous relativistic or radiation pressure models.

Findings

Resonant torquing can produce observed disk warps.

The mechanism is effective over a wide range of parameters.

It offers an alternative explanation for disk warping phenomena.

Abstract

The maser disk around the massive black hole (MBH) in active galaxy NGC 4258 exhibits an O(10 deg) warp on the O(0.1 pc) scale. The physics driving the warp are still debated. Suggested mechanisms include torquing by relativistic frame dragging or by radiation pressure. We propose here a new warping mechanism: resonant torquing of the disk by stars in the dense cusp around the MBH. We show that resonant torquing can induce such a warp over a wide range of observed and deduced physical parameters of the maser disk.