Two temperature accretion flows around rotating black holes and   determining the kerr parameter of sources
  We model two temperature viscous accretion flows in the sub-Keplerian, optically thin, regime around rotating black holes including important radiation effects self-consistently. The model successfully explains observed luminosities from ultra-luminous to under-luminous sources and predicts the spin parameter of black holes. 
Banibrata Mukhopadhyay
astro-ph.HE gr-qc