Relativistic superluminal radio jets in microquasars in our galaxy

Abstract

We discuss the origin of superluminal radio jets in Black hole X-ray binaries with relativistic radio jets in our Galaxy popularly known as microquasars. We classify the relativistic superluminal jet according to the radio emission in black hole X-ray binaries (transient or persistent) rather than the mass of the companion. The black hole X-ray binaries with transient radio emission (mostly LMXBs) produce superluminal jets with ${\beta }_{app}>$ 1 when the accretion rate, ${\dot{m}}_{accr}$ is high and the bolometric luminosity L${}_{bol}$ approaches the Eddington Luminosity, L${}_{Edd}$. On the other hand, the black hole X-ray binaries with persistent radio emission (mostly HMXBs) produce superluminal jets with ${\beta }_{app}<$ 1 at relatively low ${\dot{m}}_{accr}$. We specially discuss the case of V4641 Sgr, a HMXB with transient radio emission which produces superluminal radio jets like in LMXBs.

6 pages, 2 figures,VI Microquasar Workshop: Microquasars and Beyond, September 18-22, 2006, Como, Italy