Discovery and identification of infrared counterpart candidates of four Galactic centre low mass X-ray binaries

摘要

Context. The near infrared (nIR)/optical counterparts of low mass X-ray binaries (LMXBs) are often observationally dim and reside in high source density fields which make their identification problematic; however, without such a counterpart identification we are unable to investigate many of the properties of LMXB systems. Aims. Here, in the context of a larger identification campaign, we examine the fields of four LMXB systems near the Galactic centre, in a bid to identify nIR/optical counterparts to the previously detected X-ray point sources. Methods. We obtain nIR/optical images of the fields with the ESO - New Technology Telescope and apply standard photometric and astrometric calibrations; these data are supplemented by Spitzer-GLIMPSE catalog data. Results. On the basis of positional coincidence with the arcsecond accurate X-ray positions, we identify unambiguous counterpart candidates for XTE J1637-498, IGR J17379-3747, IGR J17585-3057 and GX 9+1. Conclusions. We propose tentative nIR counterparts of four LMXBs which require further investigation to confirm their associations to the X-ray sources.