EDP Sciences
Free access
Volume 421, Number 1, July I 2004
Page(s) 175 - 186
Section Galactic structure, stellar clusters and populations
DOI http://dx.doi.org/10.1051/0004-6361:20035869

A&A 421, 175-186 (2004)
DOI: 10.1051/0004-6361:20035869

XMM-Newton observations of the young open cluster Blanco 1

I. X-ray spectroscopy and photometry
I. Pillitteri1, G. Micela2, S. Sciortino2, F. Damiani2 and F. R. Harnden Jr.3

1  Dip. di Astronomia, Università di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
2  INAF - Osservatorio Astronomico di Palermo Piazza del Parlamento 1, 90134 Palermo, Italy
    e-mail: giusi@astropa.unipa.it, sciorti@astropa.unipa.it, damiani@astropa.unipa.it
3  Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, UK
    e-mail: frh@cfa.harvard.edu

(Received 15 December 2003 / Accepted 10 March 2004 )

We present an X-ray study of the high metallicity young open cluster Blanco 1 based on XMM-Newton data. X-ray spectroscopy of cluster members is presented for the first time as well as new X-ray distribution functions of late-type stars. We detected all known dF and dG stars in the EPIC field and 80% and 90% of dK and dM stars, respectively. The X-ray spectral analysis of the X-ray brightest cluster stars and X-ray color analysis of a larger sample show that a model with two temperatures (at about 0.3 and 1 keV) explains the quiescent activity phase spectra.

We discuss also the nature of unidentified X-ray sources in the observed region and their X-ray spectral properties.

Key words: X-ray: stars -- stars: activity -- Galaxy: open clusters and associations: individual: Blanco 1

Offprint request: I. Pillitteri, pilli@astropa.unipa.it

SIMBAD Objects

© ESO 2004