Radiation spectra of advection dominated accretion flows around Kerr blackdoles

We study the formation of the spectra in advection dominated accretion flow s (ADAFs) around Kerr black holes. We use a Monte Carlo approach and fully general relativistic treatment to follow the paths of individual photons an d model their scattering with mildly relativistic, thermal electrons of the two temperature plasma present in the flow. We study the influence of the accretion rate, black hole mass, black hole angular momentum, and the stren gth of the small scale magnetic held present in the plasma on the resulting spectra. The impact of the black hole angular momentum on the spectra is p resent and can be distinguished from the influence of changes in other para meters. This property of the models should be taken into account when model ing the individual sources and the population of inefficiently accreting bl ack holes in the Universe.