A Search for Very Active Stars in the Galaxy

Abstract

We report the first results of a systematic search near the plane of the Galaxy for the so called very active stars (VAS), which are characterized by a hard X-ray spectrum and activity in the radio domain. Candidates with hard X-ray binary-like spectra have been selected from the Bright ROSAT Source Catalogue in the Zone of Avoidance ($|b|<20{}^o$) and were tentatively identified in GB6/PMM/NVSS radio surveys. Most of them were observed with the ATCA and VLA. Precise radio coordinates have led to unambiguous optical identification for 60 candidates, and a sub-sample of five of themhas been observed with the VLT. Also some discovery and confirmatory spectra were obtained with the AAT (4-m) and BTA (6-m). Spectroscopy with moderate dispersion, made with the FORS1 spectrograph of the VLT has revealed two stellar objects (one of them, VASC J1628-41, is definitivelya binary VAS), one new AGN and two featureless spectrum sources. One of these objects, VASC J1353-66, shows a marginal evidence of proper motion, which, if confirmed, would imply the discovery of a new type of galactic source.

arXiv commentto appear in A&A, 7 figures

References in corpus (7)

• Sources of Relativistic Jets in the Galaxy
• Powerful jets from black hole X-ray binaries in Low/Hard X-ray states
• The radio luminosity of persistent X-ray binaries
• Identification of selected sources from the ROSAT Galactic Plane Survey - I
• A catalogue of galaxies behind the southern Milky Way. - II. The Crux and Great Attractor regions (l = 289deg - 338deg)
• A search for microquasar candidates at low galactic latitudes
• Optical spectroscopy of microquasar candidates at low galactic latitudes

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