Related papers: Evolution of non-thermal emission from shell assoc…
The nature of the broad-band spectra of supermassive accreting black holes in active galactic nuclei (AGNs) is still unknown. The hard X-ray spectra of Seyferts as well as of Galactic stellar-mass black holes (GBHs) are well represented by…
Shock waves associated with shell type supernova remnants are considered to be possible sites of cosmic ray acceleration. Since shocks are capable of accelerating electrons in addition to protons one anticipates both species to contribute…
Most active galactic nuclei (AGN) lack prominent jets, and show modest radio emission and significant X-ray emission which arises mainly from the galactic core, very near from the central black hole. We use a quantitative scenario of such…
Shocks in jets and hot spots of Active Galactic Nuclei (AGN) are one prominent class of possible sources of very high energy cosmic ray particles (above 10^18eV). Extrapolating their spectrum to their plausible injection energy from some…
The active galactic nuclei (AGN) lobe radio luminosities modelled in hydrodynamical simulations and most analytical models do not address the redistribution of the electron energies due to adiabatic expansion, synchrotron radiation and…
We present the first results from an X-ray and optical survey of a sample of AGN radio jets with Chandra and HST. We focus here on the first six sources observed at X-rays, in four of which a bright X-ray jet was detected for the first…
We introduce a simple and economical but effective method for including relativistic electron transport in multi-dimensional simulations of radio galaxies. The method is designed to follow explicitly diffusive acceleration at shocks, and,…
The evidence for particle acceleration in supernova shells comes from electrons whose synchrotron emission is observed in radio and X-rays. Recent observations by the HESS instrument reveal that supernova remnants also emit TeV gamma-rays;…
I propose a new mechanism for explanation of nonthernal X-ray emission of large-scale AGN jets. Namely, I assume that this radiation has synchrotron origin emitted by extremely high energy protons, and discuss implications of this model for…
Dense and cold clouds seem to populate the broad line region surrounding the central black hole in AGNs. These clouds could interact with the AGN jet base and this could have observational consequences. We want to study the gamma-ray…
Supernova 1006 is the first shell type supernova remnant to show evidence of particle acceleration to TeV energies. In the present paper we examine this possibility by modeling the observed X-ray non-thermal emission in terms of synchrotron…
This letter presents a revised radiative transfer model for the infrared (IR) emission of active galactic nuclei (AGN). While current models assume that the IR is emitted from a dusty torus in the equatorial plane of the AGN, spatially…
Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks e.g. gamma-ray bursts (GRBs) active galactic nuclei (AGNs) and microquasars commonly exhibit power-law emission spectra. Recent PIC simulations…
Two related topics are discussed. 1. Accretion onto black holes at low and high (though not very high) rates is believed to proceed adiabatically ({\em ie} non-radiatively). It is argued that the liberated energy is carried off by an…
The beaming pattern of radiation emitted by a relativistically moving source like jets in microquasars, AGN and GRBs, is a key issue for understanding of acceleration and radiation processes in these objects. In this paper we introduce a…
We describe improved modelling of the emission by dust in a toroidal--like structure heated by a central illuminating source within Active Galactic Nuclei (AGN). We chose a simple but realistic torus geometry, a flared disc, and a dust…
A new study of the diffuse Galactic gamma-ray continuum radiation is presented, using a cosmic-ray propagation model which includes nucleons, antiprotons, electrons, positrons, and synchrotron radiation. Our treatment of the inverse Compton…
A thorough study of radio emission in Active Galactic Nuclei (AGN) is of fundamental importance to understand the physical mechanisms responsible for the emission and the interplay between accretion and ejection processes. High frequency…
Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and microquasars commonly exhibit power-law emission spectra. Recent PIC…
Detection of hard X-ray spectrum (spectral index < 2) from the kilo-parsec scale jet of active galactic nuclei cannot be accounted to the synchrotron emission mechanism from the electron distribution responsible for the radio/optical…