Preprint Logo P89 February
2004


To be published in:
The Astrophysical Journal

An X-ray investigation of the NGC346 field in the SMC (3): XMM-Newton data+

Y. Nazé1,*, J. Manfroid1,**,***, I.R. Stevens2, M.F. Corcoran3 and A. Flores4


1 Institut d'Astrophysique et de Géophysique - Université de Liège, Allée du 6 Août, Bât B5c, B-4000 Liège (Sart Tilman), Belgium
2 School of Physics & Astronomy, University of Birmingham, Edgbaston Birmingham B15 2TT, United Kingdom
3 Universities Space Research Association, 7501 Forbes Blvd, Ste 206, Seabrook, MD 20706, and Laboratory for High Energy Astrophysics, Goddard Space Flight Center, Greenbelt, MD 20771, USA
4 Universidad Autonoma del Carmen, Facultad de Ingenieria, Calle 56 No 4, Cd del Carmen, Campeche, Mexico

* Research Fellow FNRS, Belgium
** Research Director FNRS, Belgium
*** Visiting Astronomer, European Southern Observatory

+ Based on observations with XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA).


Abstract

     We present new XMM-Newton results on the field around the NGC346 star cluster in the SMC. This continues and extends previously published work on Chandra observations of the same field. The two XMM-Newton observations were obtained, respectively, six months before and six months after the previously published Chandra data. Of the 51 X-ray sources detected with XMM-Newton, 29 were already detected with Chandra. Comparing the properties of these X-ray sources in each of our three datasets has enabled us to investigate their variability on times scales of a year. Changes in the flux levels and/or spectral properties were observed for 21 of these sources. In addition, we discovered long-term variations in the X-ray properties of the peculiar system HD5980, a luminous blue variable star, that is likely to be a colliding wind binary system, which displayed the largest luminosity during the first XMM-Newton observation.

Key Words
Galaxies: Magellanic Clouds - X-rays: individual (NGC346) - X-rays: galaxies: clusters - stars: individual (HD5980)

Files
Article: ngc346-3.pdf (782494 bytes): HTTP FTP (ftp://vela.astro.ulg.ac.be/preprints/)


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