Research On Characteristic Of Multi-band Spectral Energy Distribution And Evolution Of AGN

In this thesis, the basic properties, the observation of multi-band radiation and the relevant theories for AGN have been reviewed. Some problems to be discussed have been pointed out, among which a few of specific ones, related to the variability timescale, the central structure, the some characteristics for multi-band spectral energy distribution and evolution of AGN, have been investigated and are summarized as follows.Some objects of AGN were observed during some years. For PKS 1510-089, especially, based on the fact of three rapid and large-amplitude variations with very deep minima observed during 1999-2001, we predicted that this phenomenon would occur repeatedly and would be observed. In March 8 of 2002, the prediction is confirmed with the result of dense monitoring, and it is the first successful repeat observation for this kind of phenomenon. A hypothesis that suggesting a binary black hole system at the centre of PKS 1510-089 is proposed to interpret the phenomenon. The parameters of the system are estimated as: the masses of the primary andsecondary black holes are 10^8.0M(?)和10^6.2M(?), respectively; the period of orbitalmotion is 1.83±0.09yr. On the other hand, based on the supposition which the observational results of minimum variability timescale is lead to the most stable orbit of Kerr black hole, the central black hole masses of 21 blazars have been estimated, which are the closest to the results derived by Barth et al.(2003). These results show that Kerr black hole may be one of the best candidates in the nuclei of blazars.Using a new composite color-color (axax - aγxγ) diagram, where aγxγ = axγ - aγ is anew composite spectral indies which was introduced by us and axax =aox-ax bySambura et al.(1996),we investigated the nature of the HBLs-LBLs relationship, and the BL Lacs-FSRQs relationship, in high-energy emission. The results show that the optical-X-ray-γ-ray spectral energy distributions of three subclasses of GeV γ-ray loud blazers are different, but essentially continuous: HBLs and FSRQs occupy...