The complex FeK line of the Narrow-Line Seyfert 1 galaxy IRAS 13349+2438

¹ Astrophysics Group, Imperial College of Science, Technology and Medicine, Prince Consort Rd. SW7 2AZ, London, UK
² Istituto IASF-CNR, Sezione di Bologna Via Gobetti 101, 40129 Bologna, Italy
³ Universita' degli studi di Bologna, Dipartimento di Astronomia, via Ranzani 1, 40127 Bologna, Italy

Corresponding author: A. L. Longinotti, all@imperial.ac.uk

Received: 7 April 2003
Accepted: 24 July 2003

Abstract

The observation of the Narrow-Line Seyfert 1 galaxy IRAS 13349+2438 performed by XMM-Newton European Photon Imaging Camera between 0.3-10 keV, is presented here. The broadband spectrum of the source is dominated at low energies ( keV) by a strong excess of emission and by complex emission/absorption features between ~5.5-8.0 keV. The soft X-ray spectrum is consistent with ionized absorption found by the Reflection Grating Spectrometer (Sako et al. 2001a). We focus on the 2-10 keV spectrum which shows clear evidence for a broad, complex FeKα line, previously unseen by ASCA, and for an Fe K-shell edge detected at ~7.3-7.4 keV (rest-frame). The presence of this edge could be explained by either partial covering or ionized/relativistic reflection models, with the latter being preferred and with a resulting power law slope of . The line profile is complex, with a broad bump between ~5.5-6.5 keV and a narrow emission line at ~7 keV, separated by a sharp drop at ~6.8 keV. This profile is compatible with two possible scenarios: i) a broad, ionized and gravitationally redshifted Laor diskline plus a narrow and ionized emission line; ii) a broad, ionized and single Schwarzschild (double-peaked) diskline with a superimposed narrow absorption line.