Signatures of Resonant Absoprtion in X-ray Spectra of Type 1 AGN

Abstract

We present photoionization models accounting for both photoelectric and resonant absorption. We demonstrate that resonance absorption lines are detectable even in moderate resolution X-ray spectra of type 1 AGN. The spectra transmitted by gas illuminated by the ionizing continua typical of flat X-ray spectrum, broad optical emission line type 1 AGN, and steep X-ray spectrum, narrow optical emission line type 1 AGN (NLSy1) are dramatically different. In particolar, we find that both the absorption features seen in many Seyfert 1 galaxies between 0.7 and 1 keV and in several NLSy1 between 1 and 2 keV can be explained by our model, without requiring relativistic outflowing velocities of the gas.

7 pages, 3 figures, to appear in the "Vulcano Workshop 1998: Frontier Objects in Astrophysics and Particle Physics", the special series of Conference Proceedings published by the "Societa' Italiana di Fisica", F. Giovannelli and G. Mannocchi (eds.)