Gravitational Wave Heating of Stars and Accretion Disks

TL;DR

This paper explores how gravitational waves from supermassive black hole binaries can cause electromagnetic heating in nearby stars and accretion disks, but the effects are generally too faint for detection.

Contribution

It introduces a model for GW-induced heating in stars and disks, considering turbulence suppression effects, and evaluates the detectability of such EM counterparts.

Findings

Heating in stars can exceed intrinsic luminosity but remains undetectable extragalactically.

Accretion disk brightening due to GW heating is minimal.

Suppression of heating occurs when forcing period is shorter than turbulent eddy turnover time.

Abstract

We investigate the electromagnetic (EM) counterpart of gravitational waves (GWs) emitted by a supermassive black hole binary (SMBHB) through the viscous dissipation of the GW energy in an accretion disk and stars surrounding the SMBHB. We account for the suppression of the heating rate if the forcing period is shorter than the turnover time of the largest turbulent eddies. We find that the viscous heating luminosity in 0.1 solar mass stars can be significantly higher than their intrinsic luminosity, but still too low to be detected for extragalactic sources. The relative brightening is small for accretion disks.