Related papers: Factors Determining Variability Time in Active Gal…
Intensive VLBI monitoring programs of jets in AGN are showing the existence of intricate emission patterns, such as upstream motions or slow moving and quasi-stationary componentes trailing superluminal features. Relativistic hydrodynamic…
We show that there is no universal law describing how the spectra and luminosity of synchrotron and inverse Compton radiation from relativistic jets change with increasing observation angle. Instead, the physics of particle acceleration…
The extreme variability of blazars, in both timescale and amplitude, is generally explained as the effect of a relativistic jet closely aligned to the observer's line-of-sight. Due to causality arguments, variability characteristics…
We analyze the variability of the parsec-scale jet directions in active galactic nuclei (AGNs). Our analysis involves 317 AGNs at frequencies ranging from 2 to 43 GHz, and is made possible by developing an automatic inner jet direction…
Relativistic outflows in the form of jets are common in many astrophysical objects. By their very nature, jets have angle dependent velocity profiles, Gamma = Gamma(r, theta, phi), where Gamma is the outflow Lorentz factor. In this work we…
Thanks to the availability of high-resolution high-sensitivity telescopes such as the Very Large Array, the Hubble Space Telescope, and the Chandra X-ray Observatory, there is now a wealth of observational data on relativistic jets from…
We study the influence of the matter content of extragalactic jets on their morphology, dynamics and emission properties. For this purpose we consider jets of extremely different compositions including pure leptonic and baryonic plasmas.…
We study the acceleration, transport, and emission of particles in relativistic jets. Localized stochastic particle acceleration, spatial diffusion, and synchrotron as well as synchrotron self-Compton emission are considered in a leptonic…
Blazars are thought to possess a relativistic jet that is pointing toward the direction of the Earth and the elect of relativistic beaming enhances its apparent brightness. They radiate in all wavebands from the radio to the gamma-ray bands…
High energy emission from blazars is thought to arise in a relativistic jet launched by a supermassive black hole. The emission site must be far from the hole and the jet relativistic, in order to avoid absorption of the photons. In extreme…
Analysing the long-term radio variability of active galactic nuclei (AGNs) is essential to understanding the physics of relativistic jets launched by supermassive black holes. We aim to connect the characteristic timescales obtained from a…
The mechanism and the region of generation of variable continuum emission are poorly understood for radio-loud AGN because of a complexity of the nuclear region. High-resolution radio VLBI (very long baseline interferometry) observations…
Simultaneous observations of blazars in different spectral regimes imply that the amplitude of variability depends on the observational band. Both in the low energy spectral component and in the high energy spectral component, the amplitude…
The interactions between jets from active galactic nuclei (AGN) and their stellar environments significantly influence jet dynamics and emission characteristics. In low-power jets, such as those in Fanaroff-Riley I (FR I) galaxies, the…
There is now unequivocal evidence that the jets in FR I radio galaxies are initially relativistic, decelerating flows. On the assumption that they are axisymmetric and intrinsically symmetrical (a good approximation close to the nucleus),…
We demonstrate that jet observables are highly sensitive to the characteristics of the vacuum and the in-medium QCD parton showers and propose techniques that exploit this sensitivity to constrain the mechanism of quark and gluon energy…
We investigate the dynamics and morphology of jets propagating into the interstellar medium using 2D relativistic hydrodynamic simulations. The calculations are performed assuming axisymmetric geometry and trace a long propagation of jets.…
Compact relativistic jets in active galactic nuclei offer an effective tool for investigating the physics of nuclear regions in galaxies. The emission properties, dynamics, and evolution of jets in AGN are closely connected to the…
Doppler effect and Hubble effect in different models of space-time related to the space-time velocity of an observer are considered. The Doppler effect and Doppler shift frequency parameter are connected with the kinematic characteristics…
We analyze how the spectrum of synchrotron and inverse Compton radiation from a narrow relativistic jet changes with the observation angle. It is shown that diversity of acceleration mechanisms (in particular, taking the converter mechanism…