Spectral Variability in PKS 0528+134 at Gamma-Ray Energies
نویسنده
چکیده
We present model calculations to the observed spectral variability in the γ-ray spectrum of the ultraluminous blazar-type quasar PKS 0528+134. We argue that the observed appearance of a spectral break between the COMPTEL and the EGRET energy range can plausibly be explained by a variation of the Doppler beaming factor in the framework of a relativistic jet model for AGNs, combining the ERC and the SSC model. This may be an instructive example for the different dependence of these two spectral components on the Doppler factor, as predicted in earlier work.
منابع مشابه
Letter to the Editor Spectral variability in PKS 0528+134 at gamma-ray energies
We present model calculations to the observed spectral variability in the γ-ray spectrumof the ultraluminous blazartype quasar PKS 0528+134.We argue that the observed appearance of a spectral break between theCOMPTELand theEGRET energy range can plausibly be explained by a variation of the Doppler beaming factor in the framework of a relativistic jet model for AGNs, combining the ERC and the SS...
متن کاملBroadband spectral analysis of PKS 0528+134: A Report on Six Years of EGRET Observations
The multiwavelength spectra of PKS 0528+134 during six years of observations by EGRET have been analyzed using synchrotron self-Compton (SSC) and external radiation Compton models (ERC). We find that a two-component model, in which the target photons are produced externally to the gamma-ray emitting region, but also including an SSC component, is required to suitably reproduce the spectral ener...
متن کاملLeptonic Jet Models of Blazars: Broadband Spectra and Spectral Variability
The current status of leptonic jet models for gamma-ray blazars is reviewed. Differences between the quasar and BL-Lac subclasses of blazars may be understood in terms of the dominance of different radiation mechanisms in the gamma-ray regime. Spectral variability patterns of different blazar subclasses appear to be significantly different and require different intrinsic mechanisms causing gamm...
متن کاملGamma-Ray Blazars
Roughly 60 blazars have been identiied with > 100 MeV EGRET gamma-ray sources, and exhibit inferred isotropic luminosities as large as 3 10 49 ergs s ?1. The two most remarkable characteristics about the EGRET observations are that the-ray luminosity often dominates the bolometric power, and that variability on timescales at least as short as a day is seen from several sources in their aring st...
متن کاملDoes the Blazar Gamma-ray Spectrum Harden with Increasing Flux? - Analysis of Nine Years of Egret Data
The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) discovered gamma-ray emission from more than 67 blazars during its nine-year lifetime. We conducted an exhaustive search of the EGRET archives and selected all the blazars that were observed multiple times and were bright enough to enable a spectral analysis using standard power-law models. The samp...
متن کامل