Letter to the Editor

An XMM-Newton observation of IGR J16320-4751 = AX J1631.9-4752

¹ CEA Saclay, DSM/DAPNIA/SAp (CNRS FRE 2591), 91191 Gif-sur-Yvette Cedex, France
² Integral Science Data Center, Chemin d'Ecogia, 16, 1290 Versoix, Switzerland
³ Center for Astrophysics and Space Sciences, Code 0424, University of California at San Diego, La Jolla, CA 92093, USA
⁴ IASF/CNR, sezione di Bologna, via Gobetti 101, 40129 Bologna, Italy
⁵ Université Paris VII, Fédération APC, 2 place Jussieu, 75251 Paris Cedex 05, France
⁶ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA

Corresponding author: J. Rodriguez, jrodriguez@cea.fr

Received: 7 April 2003
Accepted: 3 July 2003

Abstract

The hard X-ray sensitivity and arcminute position accuracy of the recently launched International Gamma-Ray Laboratory (INTEGRAL) has lead to the (re-)discovery of a class of heavily absorbed hard X-ray sources lying in the Galactic plane. We report on the analysis of an XMM observation of such a source IGR J16320-4751 = AX J1631.9-4752. Our analysis allowed us to obtain the most accurate X-ray position to date (Rodriguez et al. [CITE]), and to identify a likely infrared counterpart (Tomsick et al. [CITE]). We present the detailed analysis of the IGR J16320-4751 XMM spectra. The PN spectrum can be well represented by a single powerlaw or a comptonized spectrum with a high equivalent absorption column density of ~ cm^-2. The current analysis and the comparison with the properties of other sources favor the possibility that the source is a Galactic X-Ray Binary (XRB). The identification of two candidate IR counterparts is in good agreement with this identification. The hard spectrum previously seen with ASCA, and the brightness of the candidate counterparts indicate that IGR J16320-4751 is most probably a highly absorbed High Mass X-ray Binary, hosting a neutron star.