Published online by Cambridge University Press: 14 August 2015
The discovery of the association between relativistic radio jets and X-ray events in GRS 1915+105 (Mirabel and Rodriguez, 1994) and GRO J1655-40 showed that strong radio flares (Harmon et al, 1994) in general, and jet ejection (Hjellming and Rupen, 1994) in particular, could be identified with features in hard X-ray events. This has caused us to re-think the interpretation of the radio events in X-ray transients, and has made multi-wavelength observations even more important. In this paper the focus is on the connection between X-ray and radio events as seen since 1994 in GRS 1915+105, GRO J1655-40, GRO J1719-24, GRO J1739-278, Cyg X-3, Cyg X-l, and Sco X-l.