Changing look: from Compton-thick to Compton-thin, or the re-birth of fossil AGN
Astrophysics
2009-11-07 v1
Abstract
We discuss the properties of a small sample of Seyfert 2 galaxies whose X-ray spectrum changed appearance on time scales of years, becoming reflection-dominated from Compton-thin, or viceversa. A reflection--dominated spectrum is usually taken as evidence of Compton-thick absorption, but we instead argue that such a spectrum is due to a temporary switching--off of the nuclear radiation. The observations discussed here may help explaining mismatches between optical and X-ray classifications, and provide new strong and direct evidence of the presence of more than one cold circumnuclear region in Seyfert 2 galaxies.
Cite
@article{arxiv.astro-ph/0302328,
title = {Changing look: from Compton-thick to Compton-thin, or the re-birth of fossil AGN},
author = {G. Matt and M. Guainazzi and R. Maiolino},
journal= {arXiv preprint arXiv:astro-ph/0302328},
year = {2009}
}
Comments
accepted for publication in MNRAS