I present new comparisons of AGN optical, UV, and X-ray variations. These reveal complex relationships between the different passbands that can change with time in a given object. While there is evidence from several objects that X-ray and optical activity levels are correlated on long timescales, variations on shorter timescales can occur independently. It is proposed that the combination of correlated and uncorrelated short-timescale variability is a consequence of anisotropic high-energy emission. It is also argued that the correlation between X-ray and optical variability on long timescales must be due to a common underlying factor and not to reprocessing of X-ray radiation.
@article{arxiv.astro-ph/0701008,
title = {Optical and X-ray Variability of AGNs},
author = {C. Martin Gaskell},
journal= {arXiv preprint arXiv:astro-ph/0701008},
year = {2007}
}
Comments
7 pages, 5 figures. In "AGN Variability from X-rays to Radio Waves", ed. C. M. Gaskell, I. M. McHardy, B. M. Peterson, and S. G. Sergeev