EDP Sciences
Free access
Volume 423, Number 1, August III 2004
Page(s) 311 - 319
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20040273

A&A 423, 311-319 (2004)
DOI: 10.1051/0004-6361:20040273

A look with BeppoSAX at the low-luminosity Galactic X-ray source 4U 2206+54

N. Masetti1, D. Dal Fiume2, L. Amati1, S. Del Sordo3, F. Frontera1, 4, M. Orlandini1 and E. Palazzi1

1  Istituto di Astrofisica Spaziale e Fisica Cosmica - Sezione di Bologna, CNR, via Gobetti 101, 40129 Bologna, Italy
    e-mail: masetti@bo.iasf.cnr.it
2  Istituto Tecnologie e Studio sulla Radiazione Extraterrestre, CNR, via Gobetti 101, 40129 Bologna, Italy
3  Istituto di Astrofisica Spaziale e Fisica Cosmica - Sezione di Palermo, CNR, via La Malfa 153, 90146 Palermo, Italy
4  Dipartimento di Fisica, Università di Ferrara, via Paradiso 12, 44100 Ferrara, Italy

(Received 16 February 2004 / Accepted 16 April 2004)

A pointed observation of the low-luminosity galactic source 4U 2206+54 was carried out in November 1998 with BeppoSAX. The light curve of 4U 2206+54 shows erratic variability on a timescale of ~1 h; neither hardness variations nor time periodicities are detected throughout this 67 ks long observation. Thanks to the wide spectral coverage capabilities of BeppoSAX we could observe the source X-ray continuum over three energy decades, from 0.6 to 60 keV. The spectrum could be equally well fitted either with a blackbody plus Comptonization or with a high energy cutoff power law. No iron emission around 6.5 keV was detected, while a tentative detection of a cyclotron resonant feature in absorption is presented. Comparison of the present BeppoSAX data with the information available in the literature for this source suggests that 4U 2206+54 is a close binary system in which a (possibly magnetized) NS is accreting from the companion star wind.

Key words: stars: binaries: close -- X-rays: binaries -- stars: neutron -- stars: individuals: 4U 2206+54 -- accretion, accretion disks

SIMBAD Objects

© ESO 2004