Letter to the Editor

INTEGRAL discovery of a bright highly obscured galactic X-ray binary source IGR J16318-4848

¹  Science Data Centre, Chemin d'Écogia 16, 1290 Versoix, Switzerland
² Observatoire de Genève, Chemin des Maillettes 51, 1290 Sauverny, Switzerland
³ CEA Saclay, DSM/DAPNIA/SAp (CNRS FRE 2591), Bât. 709, 91191 Gif-sur-Yvette Cedex, France
⁴ IASF/CNR Section of Bologna, via Pietro Gobetti 101, 40129 Bologna, Italy
⁵ SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
⁶ Université Paris VII (Fédération APC), 91191 Gif-sur-Yvette, France
⁷ Astrophysics Missions Division, Research and Scientific Support Department of ESA, ESTEC, PO Box 299, 2200 AG Noordwijk, The Netherlands
⁸ CASS, Code 0424, University of California San Diego, La Jolla, CA 92093-0424, USA
⁹ IASF/C.N.R. Section of Roma, Area di Ricerca di Tor Vergata, via del Fosso del Cavaliere, 00133 Roma, Italy

Corresponding author: R. Walter, Roland.Walter@obs.unige.ch

Received: 14 July 2003
Accepted: 4 September 2003

Abstract

INTEGRAL regularly scans the Galactic plane to search for new objects and in particular for absorbed sources with the bulk of their emission above . The first new INTEGRAL source was discovered on 2003 January 29, 0.5° from the Galactic plane and was further observed in the X-rays with XMM-Newton. This source, IGR J16318-4848, is intrinsically strongly absorbed by cold matter and displays exceptionally strong fluorescence emission lines. The likely infrared/optical counterpart indicates that IGR J16318-4848 is probably a High Mass X-Ray Binary neutron star or black hole enshrouded in a Compton thick environment. Strongly absorbed sources, not detected in previous surveys, could contribute significantly to the Galactic hard X-ray background between 10 and .