Galactic microquasars and "canonical" states of black-hole candidates

The X-ray properties of the only two known superluminal galactic sources are extremely complex and different from those of `conventional' black-hole candidates. Nevertheless, many characteristics of GRS 1915+105 and GRO J1655-40 are not unlike those expected from black-hole candidates on the basis of other known sources. I examine the timing and spectral properties of these two sources in terms of canonical black-hole states, concentrating on the similarities rather than on the peculiarities.