4U 1344-60: a bright intermediate Seyfert galaxy at z = 0.012 with a relativistic Fe K emission line

¹ Osservatorio Astronomico di Roma (INAF), via Frascati 33, 00040 Monteporzio Catone, Italy e-mail: piconcelli@mporzio.astro.it
² European Space Astronomy Center (ESA), Apartado 50727, 28080 Madrid, Spain
³ Observatoire Astronomique de Strasbourg, rue de l'Université 11, 67000 Strasbourg, France
⁴ Centre d'Étude Spatiale des Rayonnements, Avenue du Colonel Roche, BP 4346, 31028 Toulouse, France
⁵ Department of Physics & Astronomy (University of Leicester), University Road, Leicester LE1 7RH, UK
⁶ Dipartimento di Fisica (Università degli Studi Roma Tre), via della Vasca Navale 84, 00146 Roma, Italy

Received: 2 February 2006
Accepted: 9 March 2006

Abstract

We present analysis of the optical and X-ray spectra of the low Galactic latitude bright (F_2-10 = 3.6 10^-11 erg cm^-2 s^-1) source 4U 1344-60. On the basis of the optical data we propose to classify 4U 1344-60 as an intermediate type Seyfert galaxy and we measure a value of for its redshift. From the XMM-Newton observation we find that the overall X-ray spectral shape of 4U 1344-60 is complex and can be described by a power-law continuum () obscured by two neutral absorption components ( ~ 10²² cm^-2 and  ~ cm^-2), the latter covering only the ~50% of the primary X-ray source. The X-ray data therefore lend support to our classification of 4U 1344-60. It exhibits a broad and skewed Fe Kα line at ~6.4 keV, which suggests the existence of an accretion disk that is able to reprocess the primary continuum down to a few gravitational radii. Such a line represents one of the clearest examples of a relativistic line observed by XMM-Newton so far. Our analysis has also revealed the marginal presence of two narrow line-like emission features at ~4.9 and ~5.2 keV.