Galactic Superluminal Sources

A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the two galactic sources GRS 1915+105 and GRO Jl655-40. Both of these objects have given us a broader view of black holes and the formation of jets, yet they also show the complexity of the accretion environment near relativistic objects. The fast apparent motion of the jets, their luminosity and variability, their high energy spectrum, and approximately scaling to the behavior of active galactic nuclei, certainly warrant the description "microquasar". A review of the observational data on these sources is presented, and where we stand on a physical picture of GRS 1915+105 and GRO J165540 as taken from multi-wavelength studies is also discussed. Other galactic sources which share some of the properties of the microquasars, and what to look for as a high energy "signature" in future observations is also discussed.