ﻻ يوجد ملخص باللغة العربية
We present BeppoSAX observations of three gamma-ray emitting quasars, namely 0836+710, 1510-089 and 2230+114. The three objects have been detected up to 100 keV showing extremely flat power-law spectra above 2 keV (energy index alpha_{2-10}=0.3-0.5). The soft X-ray spectrum of 0836+710 implies either an absorption column density higher than the galactic one or an intrinsically very hard slope (alpha_{0.1-1}=-0.2) below 1 keV. 1510-089 shows a soft excess, with the low energy spectrum steeper (alpha_{0.1-1}=1.6) than the high energy power-law. The results are discussed in the framework of current Inverse Compton models for the high energy emission of Flat Spectrum Radio Quasars and are used to estimate the physical quantities in the jet emitting region and to shed light on the energy transport mechanisms in jets. Finally we discuss the estimates of the jet luminosity in the context of the Blandford & Znajek mechanism for jet production.
We present new hard X-ray spectra of three radio-loud AGNs of moderately high X-ray luminosity (L_x ~ 10^45 erg/s; PKS 2349-01, 3C 323.1, and 4C 74.26) obtained with ASCA and BeppoSAX. The X-ray continua are described in all three cases with a power
We present new BeppoSAX LECS, MECS, and PDS observations of four flat-spectrum radio quasars (FSRQ) having effective spectral indices alpha_ro and alpha_ox typical of high-energy peaked BL Lacs. Our sources have X-ray-to-radio flux ratios on average
In the unification scheme, radio quasars and FR II radio galaxies come from the same parent population, but viewed at different angles. Based on the Comptonization models for the gamma-ray emission from active galactic nuclei (AGNs), we estimate the
We present results from the analysis of a BeppoSAX observation of the Centaurus Cluster. The radial metal abundance profile shows evidence of a large enhancement in the core, where Ab $>$ 1 (sol. units). The temperature map indicates that the cluster
We present new results from BeppoSAX observations of reflection-dominated Seyfert galaxies, and namely: 1) the Compton-thick Seyfert 2s NGC1068 and Circinus Galaxy; 2) the Seyfert 1 NGC4051, whose nucleus was observed on May 1998 to have switched off