Related papers: Gamma rays from jets interacting with BLR clouds i…
Recent HST observations suggest that the NLR in Seyfert Galaxies can be the result of interaction between jet and external inhomogeneous medium; following this suggestion we perform numerical simulations considering the impact of a…
Blazars are among the most powerful extragalactic objects, as a sub-class of active galactic nuclei. They launch relativistic jets and their emitted radiation shows strong variability across the entire electro-magnetic spectrum. The…
3C 84 is a nearby Active Galactic Nucleus (AGN) that is unique in that is believed that we are observing near the true jet launching region - unlike blazars. The source is active in Gamma rays and has been detected with Fermi since its…
X-ray emission from large scale extragalactic jets is likely to be due to inverse Compton scattering of relativistic particles off seed photons of both the cosmic microwave background field and the blazar nucleus. The first process…
We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGN), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma rays from AGN interact with…
We present a series of numerical studies of the interaction of colliding radiative, hydrodynamic young stellar outflows. We study the effect of the collision impact parameter on the acceleration of ambient material and the degree to which…
We discuss a role of the boundary shear layer of large scale jets for their observed multiwavelength emission. We consider a simple mechanism of a turbulent particle acceleration acting within such regions as an alternative mechanism with…
We have investigated how varying several parameters affects the results of a collision between an extragalactic jet and a dense, intergalactic cloud, through a series of hydrodynamic simulations. We have produced synthetic radio images for…
Blazars, a beamed population of active galactic nuclei, radiate high-energy gamma-rays, and thus are a good target for the Gamma Ray Large Area Space Telescope (GLAST). As the blazars trace the large-scale structure of the universe, one may…
It is now generally accepted that long gamma-ray bursts are associated with the final evolutionary stages of massive stars. As a consequence, their jets must propagate through the stellar progenitor and break out on their surface, before…
High redshift blazars are among the most powerful non-explosive sources in the Universe and play a crucial role in understanding the evolution of relativistic jets. To understand these bright objects, we performed a detailed investigation…
We examine a model for the observed temporal variability of powerful blazars in the $\gamma$-ray band in which the dynamics is described in terms of a stochastic differential equation, including the contribution of a deterministic drift and…
Accumulating observational evidence for a number of radio galaxies suggests an association between their jets and regions of active star formation. The standard picture is that shocks generated by the jet propagate through an inhomogeneous…
The class of Compact Steep-spectrum Sources is dominated by double-lobed objects (70%). The remaining 30% are jet-dominated objects, with the jet brightened either by Doppler boosting or by interaction with the ambient media. We show that…
The radio light curve and spectral evolution of the blazar CTA 102 during its 2006 outburst can be rather well explained by the standard shock-in-jet model. The results of a pixel-to-pixel spectral analysis of multi-frequency VLBI images,…
In the subclass of high-mass X-ray binaries known as "microquasars", relativistic hadrons in the jets launched by the compact object can interact with cold protons from the star's radiatively driven wind, producing pions that then quickly…
Gamma-ray flares of blazars may be accompanied by high-energy neutrinos due to interactions of high-energy cosmic rays in the jet with photons, as suggested by the detection of the high-energy neutrino IceCube-170922A during a major…
Recent observations indicate that stripped-envelope core-collapse supernovae are often surrounded by dense circumstellar material (CSM). Motivated by this, we develop an analytic model to systematically study the dynamics of long gamma-ray…
Supercriticality of the same kind as that in a nuclear pile can take place in high-energy astrophysical objects producing a number of impressive effects. For example, it could cause an explosive release of the energy of a cloud of…
We discuss a theoretical scheme that accounts for bulk matter, jets, and the interaction between the two. The aim is a complete description of particle production at all transverse momentum ($p_{t}$) scales. In this picture, the hard…