The complex X-ray absorbers of NGC 3516 observed by BeppoSAX
Abstract
In this paper we present the analysis of two broad band (0.1-150 keV) BeppoSAX observations of the Seyfert 1 galaxy NGC 3516. The two observations were taken 4 months apart, on 1996 November 8 and 1997 March 12 respectively. We report a dramatic change in the degree of obscuration of the central source between the two observations, and propose, as possible explanations transient absorption by either a stationary-state cloud of cold gas crossing the line of sight, or a varying-state, initially neutral and dense amount of expanding gas with decreasing density and therefore decreasing opacity. We also report the detection of a second highly ionized absorber/emitter, which causes deep FeXVII-XXII K edges at about 7.8 keV to appear in both BeppoSAX spectra of NGC 3516, and possibly produces the soft X-ray continuum emission and the 1 keV blend of Fe L recombination lines detected during the epoch of heavy nuclear obscuration.
Cite
@article{arxiv.astro-ph/0007158,
title = {The complex X-ray absorbers of NGC 3516 observed by BeppoSAX},
author = {E. Costantini and F. Nicastro and A. Fruscione and S. Mathur and A. Comastri and M. Elvis and F. Fiore and C. Salvini and G. M. Stirpe and C. Vignali and B. Wilkes and P. T. O'Brien and M. R. Goad},
journal= {arXiv preprint arXiv:astro-ph/0007158},
year = {2009}
}
Comments
30 pages, 5 eps figures, AAS Latex, accepted for publication in The Astrophysical Journal