riassunto2

Speaker	GHOSH, HIMADRI
Co-autors	*S. K. Garain, Kinsuk Giri, Sandip K. Chakrabarti*
Talk Title	Monte-Carlo Simulations of Thermal Comptonization Process in a Two Component Accretion Flow Around a Black Hole: spectral change due to the presence of the outflow.
Abstract	We compute the effects of thermal Comptonization of soft photons emitted from a Keplerian disk around a black hole by the post-shock region of a sub-Keplerian flow, known as the CENtrifugal pressure dominated BOundary Layer (CENBOL). We show that the spectral state transitions of black hole candidates can be explained either by varying the outer boundary of the CENBOL, which also happens to be the inner edge of the Keplerian disk, or by changing the central density of the CENBOL which is governed by the rate of the sub-Keplerian flow. We study the change in the spectrum in presence of an outflow and conclude that the increase of the accretion rate of the inflowing matter makes the spectrum harder, also if the percentage of matter being carried away by the jet increases the spectrum becomes harder. We also find that the effect of the inflowing matter on the net output spectrum is much more dominant than the diverging outflow. We confirm the conclusions of the previous theoretical studies that the interplay between the intensity of the soft photons emitted by the Keplerian flow and the optical depth and electron temperature of the Comptonizing cloud is responsible for the state transitions in a black hole.
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