The complex FeK line of the narrow-line seyfert 1 galaxy IRAS 13349+2438

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 (E ≤ 2 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 Γ ∼ 2.2. 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.