Relativistic superluminal radio jets in microquasars in our galaxy

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 βapp > 1 when the accretion rate, ṁaccr is high and the bolometric luminosity Lbol approaches the Eddington Luminosity, LEdd . On the other hand, the black hole X-ray binaries with persistent radio emission (mostly HMXBs) produce superluminal jets with βapp < 1 at relatively low ṁaccr. We specially discuss the case of V4641 Sgr , a HMXB with transient radio emission which produces superluminal radio jets like in LMXBs.