The infrared counterpart of the Z source GX 5–1 |
| |
| Authors: | P G Jonker R P Fender N C Hambly M van der Klis |
| |
| Institution: | Astronomical Institute 'Anton Pannekoek', University of Amsterdam, and Center for High-Energy Astrophysics, Kruislaan 403, 1098 SJ, Amsterdam, the Netherlands;Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ |
| |
| Abstract: | We have obtained UK Infrared Telescope infrared observations of the field of the bright Galactic Z source GX 5–1. From an astrometric plate solution tied to Tycho–ACT standards we have obtained accurate positions for the stars in our field which, combined with an accurate radio position, have allowed us to identify the probable infrared counterpart of GX 5–1. Narrow-band photometry marginally suggests excess Br γ emission in the counterpart, supporting its association with an accretion-disc source. No significant variability is observed in a limited number of observations. We compare the H and K magnitudes with those of other Z sources, and briefly discuss possible sources of infrared emission in these systems. |
| |
| Keywords: | binaries: close stars: individual: GX 5–1 infrared: stars |
|
|
