The Spectra Of Inhomogeneous Accretion Flow

Black hole accretion is a crucial process in high energy astrophysics.The accretion mode of the states transition of black hole X-ray binaries is still not well understood yet.Based on the observational phenomena and theoretic calculation,the inhomogeneous accretion flow was proposed by some authors to explain the properties of black hole X-ray binaries.In this dissertation,based on the phenomenological model of the in-homogeneous accretion flow,the continuum and relativistic Fe K? line are calculated.And we use the results to explore whether the existence of inhomogeneous accretion flow can be convinced observationally by using the feature of thermal component and relativistic Fe Ka line.In Section 1,we will make an abbreviated introduction about the basic physical mechanism,such as,accretion theory,radiation theory,the states of black hole X-ray binaries and inhomogeneous accretion flow.In Section 2,we discuss the continuum of the inhomogeneous accretion flow,which is calculated by using Monte Carlo method.Our results show that there is a warp in the middle part of the thermal component,which is a power-law with its slop being 4/3 if the cold disc is standard thin disc.This feature give us a possible method to test the inhomogeneous accretion flow model.Unfortunately,the warp feature is in the energy band where other components may have a prominent affection,e.g.,soft X-ray excess,and the significant absorption due to interstellar medium.Therefore,more works are needed to be done to explore,after these factors are taken into account,whether the warp feature is still able to give us the clues about the inhomogeneous ac-cretion flow.Except for the warp feature,our results also indicate that,in the case that a large enough cold clump exists in the innermost region of the accretion system,the relationship between the spectral index ? and the luminosity of the thermal component Ldis,could be rather simple,which enables us to constrain the accretion mode of the states transition.In Section 3,we discuss the relativistic Fe K? line of the inhomogeneous accretion flow,which is calculated by using ray-tracing technique.Our results show that the profiles of relativistic Fe Ka line show multi-peak structure when the emissivity index is smaller than a critical value.Even if the thermal Doppler effect is taken into account,the multi-peak structure could be still detectable.Therefore,the profile of relativistic Fe Ka line,in principle,could be used as the indicator of inhomogeneous accretion flow.Moreover,our results also indicate that,when the accretion system have a medium inclination,the inclination angle is possible to be underestimated when we use the relativistic Fe K? line of continuous disc to estimate the inhomogeneous accretion flow.As first step,we simplify the inhomogeneous accretion flow as a series of neutral rings.Further works should be done to explore the realistic and ionized accretion flow.