Related papers: Shocks, clouds and atomic outflows in active galac…
The interstellar medium (ISM) is constantly evolving due to unremitting injection of energy in various forms. Energetic radiation transfers energy to the ISM: from the UV photons, emitted by the massive stars, to X- and $\gamma$-ray ones.…
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…
Outflows and winds launched from young stars play a crucial role in the evolution of protostars and the early stages of planet formation. However, the specific details of the mechanism behind these phenomena, including how they affect the…
The termination regions of non-relativistic jets in protostars and supersonic outflows in classical novae are nonthermal emitters. Given the high densities in these systems, radiative shocks are expected to form. However, in the presence of…
Hydrodynamical simulations of jets interacting with clouds moving in the ambient medium of the host galaxy are presented. Clouds with sizes of the order of the jet diameter and smaller, crossing the path of the jet with different speeds are…
Jets powered by active galactic nuclei appear impressively stable compared with their terrestrial and laboratory counterparts-they can be traced from their origin to distances exceeding their injection radius by up to a billion times.…
Outflows in the Active Galactic Nucleus (AGN) are considered to play a key role in the host galaxy evolution through transfer of a large amount of energy. A Narrow Line Region (NLR) in the AGN is composed of ionized gas extending from…
Observations of emission lines in Active Galactic Nuclei (AGN) often find fast (~1000 km s^-1) outflows extending to kiloparsec scales, seen in ionised, neutral atomic and molecular gas. In this work we present radiative transfer…
Ionization cones and relativistic jets give us one of the most large-scale example of active galactic nuclei (AGN) influence on the surrounding gas environment in galaxies and beyond. The study of ionization cones makes it possible not only…
The transverse stratification of active galactic nuclei (AGN) jets is suggested by observations and theoretical arguments, as a consequence of intrinsic properties of the central engine (accretion disc + black hole) and external medium. On…
Astrophysical sources of relativistic jets or outflows, such as gamma-ray bursts (GRBs), active galactic nuclei (AGN) or micro-quasars, often show strong time variability. Despite such impulsive behavior, most models of these sources assume…
In this paper, we review recent and ongoing work by our group on numerical simulations of relativistic jets. Relativistic outflows in Astrophysics are related to dilute, high energy plasmas, with physical conditions out of the reach of…
We report some key results from the optical emission line study of a complete sample of compact radio sources. We find strong evidence for jet-driven outflows in the circum-nuclear emission line gas namely: 1) highly broadened and…
In Part I of this paper we described an equilibrium model of a jet in the gravitational field corresponding to the rigid-rotation region of the galactic disk. We used linear stability analysis to find the waveguide-resonance instability of…
Collimated relativistic outflows, or jets, are amongst the most energetic and relativistic phenomena in the Universe. They are associated with supermassive black holes in distant active galactic nuclei (AGN), accreting black holes and…
It is well known that active galactic nuclei (AGN) show various forms of interaction with their host galaxy, in a number of phenomena generally called AGN feedback. In particular, the relativistic plasma jets launched by a fraction of AGN…
The propagation of extragalactic jets is studied by a series of twelve axisymmetric hydrodynamic simulations. Motivated by observational constraints, but unlike most previous simulations, the regime of jet to external medium density (eta)…
Relativistic jets from Active Galactic Nuclei (AGN) are highly energetic and emit radiation across a wide range of frequencies. Despite several observational studies, their particle composition still remains a key open question. The…
This letter presents a numerical study of the evolution of an emission line cloud of initial density 10 cm$^{-3}$, temperature $10^4$ K, and size 200 pc, being overtaken by a strong shock wave. Whereas previous simple models proposed that…
We present results of a detailed numerical study and theoretical analysis of the dynamics of internal shocks in relativistic jets and the non-thermal flares associated with these shocks. In our model internal shocks result from collisions…