X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk 509

¹ INAF-IASF Bologna, via Gobetti 101, 40129 Bologna, Italy e-mail: cappi@iasfbo.inaf.it
² Dipartimento di Astronomia, Università degli Studi di Bologna, via Ranzani 1, 40127 Bologna, Italy
³ Department of Physics and Astronomy, Johns Hopkins University, 3400, Baltimore, MD 21218, USA
⁴ Laboratory for High Energy Astrophysics, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
⁵ Dipartimento di Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, 00146, Roma, Italy
⁶ Department of Astronomy & Astrophysics, Pennsylvania State University, University Park, PA 16802, USA
⁷ INAF - Osservatorio Astronomica di Brera, via Brera 28, 20121, Milano, Italy
⁸ Laboratoire d'Astrophysique de Grenoble, Université Joseph-Fourier/CNRS UMR 5571, 38041 Grenoble, France
⁹ APC Université Paris 7 Denis Diderot, 75205 Paris, France

Received: 23 March 2009
Accepted: 8 June 2009

Abstract

Context. There is growing evidence for the presence of blueshifted Fe K absorption lines in a number of radio-quiet AGNs and QSOs. These may be fundamental to probe flow dynamics near supermassive black holes.

Aims. Here we aim to verify and better characterise the existence of such Fe K absorption at ~8–10 keV in the luminous Seyfert 1 galaxy Mrk 509, one of the most promising target for these studies.

Methods. We present a comprehensive spectral analysis of the six XMM-Newton observations of the source (for a total of ~200 ks), focusing on a detailed and systematic search for absorption features in the high-energy data.

Results. We detect several absorption features at rest-frame energies ~8–8.5 keV and ~9.7 keV. The lines are consistent with being produced by H-like iron Kα and Kβ shell absorptions associated with an outflow with a mildly relativistic velocity of ~0.14–0.2 c. The lines are found to be variable in energy and, marginally, in intensity, implying variations in either the column density, geometry and/or ionization structure of the outflow are common.