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Title: Continuum Reverberation Mapping of Mrk 876 over Three Years with Remote Robotic Observatories

Continuum reverberation mapping probes the size scale of the optical continuum-emitting region in active galactic nuclei (AGN). Through 3 yr of multiwavelength photometric monitoring in the optical with robotic observatories, we perform continuum reverberation mapping on Mrk 876. All wave bands show large-amplitude variability and are well correlated. Slow variations in the light curves broaden the cross-correlation function (CCF) significantly, requiring detrending in order to robustly recover interband lags. We measure consistent interband lags using three techniques (CCF, JAVELIN, and PyROA), with a lag of around 13 days fromutoz. These lags are longer than the expected radius of 12 days for the self-gravitating radius of the disk. The lags increase with wavelength roughly followingλ4/3, as would be expected from thin disk theory, but the lag normalization is approximately a factor of 3 longer than expected, as has also been observed in other AGN. The lag in theiband shows an excess that we attribute to variable Hαbroad-line emission. A flux–flux analysis shows a variable spectrum that followsfνλ−1/3, as expected for a disk, and an excess in theiband that also points to strong variable Hαemission in that band.

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Award ID(s):
1907290 1907208 1909199
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Medium: X Size: Article No. 137
Article No. 137
Sponsoring Org:
National Science Foundation
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