X-ray absorption variability in NGC 4507
Abstract
We present a complete spectral analysis of an XMM-Newton and Chandra campaign of the obscured AGN in NGC 4507, consisting of six observations spanning a period of six months, ranging from 2010 June to December. We detect strong absorption variability on time-scales between 1.5 and 4 months, suggesting that the obscuring material consists of gas clouds at parsec-scale distance. The lack of significant variability on shorter time-scales suggests that this event is not due to absorption by broad-line region (BLR) clouds, which was instead found in other studies of similar sources. This shows that a single, universal structure of the absorber (either BLR clouds, or the parsec-scale torus) is not enough to reproduce the observed complexity of the X-ray absorption features of this AGN.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- March 2013
- DOI:
- 10.1093/mnras/sts534
- arXiv:
- arXiv:1212.4151
- Bibcode:
- 2013MNRAS.429.2581M
- Keywords:
-
- Galaxies: active;
- Galaxies: Seyfert;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- Accepted for publication in MNRAS, 7 pages, 5 figures, 1 table