Letter to the Editor

IGR J17497-2821: a new X-ray nova

¹ Science Data Centre, Chemin d'Écogia 16, 1290 Versoix, Switzerland
² Geneva Observatory, University of Geneva, Chemin des Maillettes 51, 1290 Sauverny, Switzerland e-mail: Roland.Walter@obs.unige.ch
³ N. Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland
⁴ AIM - Astrophysique Interactions Multi-Échelles, CEA Saclay, DSM/DAPNIA/SAp, Bât. 709, L'Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France
⁵ ISOC, ESAC/ESA, Apartado 50727, 28080 Madrid, Spain
⁶ NASA Goddard Space Flight Center, Astrophysics Science Division, Greenbelt, MD 20771, USA
⁷ University of Maryland Baltimore County, Joint Center for Astrophysics, 1000 Hilltop Circle, Baltimore, MD 21250, USA
⁸ Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium

Received: 7 October 2006
Accepted: 17 November 2006

Abstract

Context.A new hard X-ray transient has been discovered by INTEGRAL on 2006 Sep. 17 at 1 degree from the Galactic Centre.

Aims.INTEGRAL, Swift/XRT and optical photometric observations are used to characterize IGR J17497–2821 and to unveil its nature.

Methods.The X-ray position has been refined to arcsec level through a study of the optical variability of the possible counterparts. Hard X-ray variability and spectroscopy are used to determine the nature of the source outburst.

Results.IGR J17497–2821 is a new X-ray Nova in low-hard state, probably a new Black-Hole Candidate.