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H. A. Harutyunian 《Astrophysics》2004,47(4):538-546
The hypothesis that the spectra of young objects contain an anomalous red shift which decreases and disappears as they evolve is considered. The possibility of detecting features of this anomalous red shift in the spectra of postquasar objects is considered under the assumption that a large fraction of the quasars are local objects ejected from galactic nuclei. It is argued that the anomalous red shift has a significant effect on the form of the observed luminosity function for the local population of galaxies, depleting it at faint magnitudes. This approach is used to examine the problem of excess blue galaxies. 相似文献
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A. C. Fabian 《Astrophysics and Space Science》2005,300(1-3):97-105
Several AGN and black hole X-ray binaries show a clear very broad iron line, which is strong evidence that the black holes
are rapidly spinning. Detailed analysis of these objects shows that the emission line is not significantly affected by absorption
and that the source variability is principally due to variation in amplitude of a power-law. Underlying this is a much less
variable, relativistically-smeared, reflection-dominated, component which carries the imprint of strong gravity at a few gravitational
radii. The strong gravitational light bending in these regions then explains the power-law variability as due to changes in
height of the primary X-ray source above the disc. The reflection component, in particular its variability and the profile
of the iron line, enables us to study the innermost regions around an accreting, spinning, black hole. 相似文献
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We describe the dynamical evolution of hotspots velocity, pressure and mass density in radio-loud active galactic nuclei (AGNs), taking proper account of (1) the conservations of the mass, momentum and kinetic energy flux of the unshocked jet, (2) the deceleration process of the jet by shocks and (3) the cocoon expansion without assuming the constant aspect ratio of the cocoon. By the detailed comparison with two-dimensional relativistic hydrodynamic simulations, we show that our model well reproduces the whole evolution of relativistic jets. Our model can explain also the observational trends of the velocity, the pressure, the size and mass density of hotspots in compact symmetric objects (CSOs) and Fanaroff–Riley type II (FR II) radio galaxies. 相似文献