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The complex X-ray absorbers of NGC 3516 observed by BeppoSAX

E. Costantini·F. Nicastro·A. Fruscione·S. Mathur·A. Comastri·M. Elvis·F. Fiore·C. Salvini·G. M. Stirpe·C. Vignali·B. Wilkes·P. T. O'Brien·M. R. Goad
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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.

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E. Costantini, F. Nicastro, A. Fruscione, S. Mathur, A. Comastri, M. Elvis, F. Fiore, C. Salvini, G. M. Stirpe, C. Vignali, B. Wilkes, P. T. O'Brien, M. R. Goad. 2000-07-12. The complex X-ray absorbers of NGC 3516 observed by BeppoSAX. https://doi.org/10.1086/317200

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