The influence of bulk motion on comptonization in advectively dominated accretion flows

We consider Comptonization of soft photons inside advection dominated accre tion hows (ADAFs). We use Monte Carlo simulations to follow the individual photon paths. We investigate the influence of the bulk motion on the spectr a and find it to be weak. We find that the slope of the spectrum from radio to gamma range can be estimated if the probability and average energy gain in the first photon scattering are known.