A search for radio counterparts to Chandra ULX candidates

Abstract

We present a systematic search for radio counterparts to Ultra Luminous X-ray (ULX) source candidates based on a cross-correlation of the Swartz et al. (2004) ULX catalogue based on Chandra data and the FIRST radio survey. We find seven cases of conspiscuous peaks of radio emission that could be associated to ULX sources. Among these seven ULX radio candidates, three X-ray sources are located within 5" of the FIRST radio peaks. These three cases are shown and discussed individually.

5 pages, 3 figures. Accepted for publication in the Astronomische Nachrichten, to appear in the proceedings of the conference "Ultra-Luminous X-ray sources and Middle Weight Black Holes" (Madrid, May 24-26, 2010). Resubmission corrects the Authors list and the acknowledgements