Related papers: Gamma rays from jets interacting with BLR clouds i…
Jet-cloud interactions are a key manifestation of Active Galactic Nucleus (AGN) feedback on nuclear scales, distinct from the large-scale radio-mode feedback that suppresses gas cooling in galaxy halos. On these smaller scales, radio jets…
We consider models for gamma-ray bursts in which a collimated jet expands either into a homogeneous medium or into a stellar wind environment, and calculate the expected afterglow temporal behavior. We show that (i) following a break and a…
This paper reviews the topic of sub-parsec - scale jets in quasars, and covers the the following issues: observations of parsec and sub-parsec scale jets; energy dissipation and particle acceleration; radiative processes; magnetic fields,…
A recent progress in the study of $\gamma$-ray jets is reviewed, with a focus on some theoretical interpretations of the VHE emission from M87, and possibly other misaligned blazars; the connection betwe en the GeV breaks exhibited by…
The internal-shocks scenario in relativistic jets has been used to explain the variability of blazars' outflow emission. Recent simulations have shown that the magnetic field alters the dynamics of these shocks producing a whole zoo of…
Relativistic jets of active galactic nuclei have been known to exist for 100 years. Blazars with their jet pointing close to our line of sight are some of the most variable and extreme objects in the universe, showing emission from radio to…
The author presents a model for variability of the flux and polarization of blazars in which turbulent plasma flowing at a relativistic speed down a jet crosses a standing conical shock. The shock compresses the plasma and accelerates…
The observed spectra of blazars, their intrinsic emission, and the underlying populations of radiating particles are intimately related. The use of these sources as probes of the extragalactic infrared background, a prospect propelled by…
We present the results of a set of numerical simulations of long-duration gamma-ray burst jets associated with massive, compact stellar progenitors. The simulations extend to large radii and allow us to locate the region in which the peak…
We consider the shock structures that can arise in blazar jets as a consequence of variations in the jet flow velocity. There are two possible cases: (1) A double shock system consisting of both a forward and reverse shock (2) A single…
The expected level of gamma-gamma absorption in the Broad Line Region (BLR) radiation field of gamma-ray loud Flat Spectrum Radio Quasars (FSRQs)is evaluated as a function of the location of the gamma-ray emission region. This is done…
We examine and develop the model of gamma ray bursts origin proposed by Shaviv and Dar (astro-ph/9606032), according to which the strong gamma ray emission is produced by the interaction of the baryonic relativistic jet (outflow) with the…
In high-mass microquasars (HMMQ), strong interactions between jets and stellar winds at binary system scales could occur. In order to explore this possibility, we have performed numerical 2-dimensional simulations of jets crossing the dense…
Molecular clouds interacting with supernova remnants may be subject to a greatly enhanced irradiation by cosmic rays produced at the shocked interface between the ejecta and the molecular gas. Over the past decade, broad-band observations…
The jets of microquasars with high-mass stellar companions are exposed to the dense matter field of the stellar wind. We present estimates of the gamma-ray emission expected from the jet-wind hadronic interaction and we discuss the…
Feedback driven by jets from active galactic nuclei is believed to be responsible for reducing cooling flows in cool-core galaxy clusters. We use simulations to model feedback from hydrodynamic jets in isolated halos. While the jet…
Due to its powerful radiation over the entire electromagnetic spectrum and its radio jet activity, the blazar 3C273 offers the opportunity to study the physics of $\gamma$-ray emission from active galactic nuclei. Since a historically…
Blazars, a class of active galaxies whose jets are relativistic and collimated flows of plasma directed along the line of sight and are prone to a slew of magneto-hydrodynamic (MHD) instabilities. We aim to study the interplay of radiation…
Neumayer et al. established the existence of a blue-shifted cloud in the core of Centaurus A, within a few parsecs of the nucleus and close to the radio jet. We propose that the cloud has been impacted by the jet, and that it is in the…
The blast-wave model for gamma-ray bursts (GRBs) has been called into question by observations of spectra from GRBs that are harder than can be produced through optically thin synchrotron emission. If GRBs originate from the collapse of…