Black holes: accretion processes in X-ray binaries

Accretion onto black holes is one of the most efficient energy source in the Universe. Black hole accretion powers some of the most luminous objects in the universe, including quasars, active galactic nuclei, tidal disruption events, gamma-ray bursts, and black hole X-ray transients. In the present review, we give an astrophysical overview of black hole accretion processes, with a particular focus on black hole X-ray binary systems. In Section 1, we briefly introduce the basic paradigms of black hole accretion. Physics related to accretion onto black holes are introduced in Section 2. Models proposed for black hole accretion are discussed in this section, from the Shakura-Sunyaev thin disk accretion to the advective-dominated accretion flow. Observational signatures that make contact to stellar-mass black hole accretion are introduced in Section 3, including the spectral and fast variability properties. A short conclusion is given in Section 4.