A characteristic optical variability timescale in astrophysical accretion disks
Abstract
Accretion disks around supermassive black holes in active galactic nuclei produce continuum radiation at ultraviolet and optical wavelengths. Physical processes in the accretion flow lead to stochastic variability of this emission on a wide range of timescales. We measure the optical continuum variability observed in 67 active galactic nuclei and the characteristic timescale at which the variability power spectrum flattens. We find a correlation between this timescale and the black hole mass, extending over the entire mass range of supermassive black holes. This timescale is consistent with the expected thermal timescale at the ultraviolet-emitting radius in standard accretion disk theory. Accreting white dwarfs lie close to this correlation, suggesting a common process for all accretion disks.
Keywords
Cite
@article{arxiv.2108.05389,
title = {A characteristic optical variability timescale in astrophysical accretion disks},
author = {Colin J. Burke and Yue Shen and Omer Blaes and Charles F. Gammie and Keith Horne and Yan-Fei Jiang and Xin Liu and Ian M. McHardy and Christopher W. Morgan and Simone Scaringi and Qian Yang},
journal= {arXiv preprint arXiv:2108.05389},
year = {2021}
}
Comments
Author's version; 49 pages; Science (published Aug 13)