IR observations of X-ray binaries

Abstract

We present here the results of infrared observations on the two superluminal galactic X-ray sources (GRS 1915+105 and GRO J1655-40) and 4U 1755-33. All sources have variable infrared counterparts in the JHK bands. Observations of GRS 1915+105 during the 1994 outburst showed the presence of strong emission lines in the K-band. GRO J1655-40 was observed during a period between two X-ray outbursts, showing weaker emission lines than those of GRS 1915+105. The X-ray source 4U 1755-33 was also observed recently, few months after its off X-ray state reported by RXTE.