A characteristic optical variability time scale in astrophysical accretion disks.

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Bibliographic Details
Title: A characteristic optical variability time scale in astrophysical accretion disks.
Authors: Burke, Colin J., Shen, Yue, Blaes, Omer, Gammie, Charles F., Horne, Keith, Jiang, Yan-Fei, Liu, Xin, McHardy, Ian M., Morgan, Christopher W., Scaringi, Simone, Yang, Qian
Source: Science (pre-March 2025). 8/13/2021, Vol. 373 Issue 6556, p789-792. 4p. 1 Color Photograph, 2 Diagrams.
Subjects: Supermassive black holes, Black holes, Optical wavelength conversion, Compact objects (Astronomy), Accretion (Astrophysics)
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 time scales. We measured the optical continuum variability observed in 67 active galactic nuclei and the characteristic time scale at which the variability power spectrum flattens. We found a correlation between this time scale and the black hole mass extending over the entire mass range of supermassive black holes. This time scale is consistent with the expected thermal time scale 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. [ABSTRACT FROM AUTHOR]
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Database: Psychology and Behavioral Sciences Collection
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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 time scales. We measured the optical continuum variability observed in 67 active galactic nuclei and the characteristic time scale at which the variability power spectrum flattens. We found a correlation between this time scale and the black hole mass extending over the entire mass range of supermassive black holes. This time scale is consistent with the expected thermal time scale 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. [ABSTRACT FROM AUTHOR]
ISSN:00368075
DOI:10.1126/science.abg9933