相关论文: Altered Luminosity Functions of Relativistically B…
The observed apparent velocities and luminosities of the relativistic jets in AGNs are significantly different from their intrinsic values due to strong special relativistic effects. We adopt the maximum likelihood method to determine…
We study the statistics of gamma-ray bursts, assuming that gamma-ray bursts are cosmological and they are beamed in the form of a conical jet with a large bulk Lorentz factor $\sim 100$. In such a conic beam, the relativistic ejecta may…
We reinvestigate the problem of the appearance of relativistic jets when geometrical opening is taken into account. We propose a new criterion to define apparent velocities and Doppler factors, which we think being determined by the…
Relations between the observed quantities for a beamed radio jet, apparent transverse speed and apparent luminosity (beta_app,L), and the intrinsic quantities, Lorentz factor and intrinsic luminosity (gamma,L_o), are investigated. The…
Observations of blazar jets are shrouded in relativistic effects, thus hindering our understanding of their intrinsic properties and dominant physical processes responsible for their generation, evolution,radiation and particle emission. In…
We investigate the dependence of gamma-ray brightness of blazars on intrinsic properties of their parsec-scale radio jets and the implication for relativistic beaming. By combining apparent jet speeds derived from high-resolution VLBA…
The question of the collimation of relativistic jets is the subject of a lively debate in the community. We numerically compute the apparent velocity and the Doppler factor of a non homokinetic jet using different velocity profile, to study…
Blazar radiation is dominated by a relativistic jet which can be modeled at first approximation using just two intrinsic parameters - the Lorentz factor $\Gamma$ and the viewing angle $\theta$. Blazar jet observations are often beamed due…
Radio maps of AGNs often show linear features, called jets, both on pc as well as kpc scales. These jets supposedly possess relativistic motion and are oriented close to the line of sight of the observer and accordingly the relativistic…
It is shown that the two-sided jet proper motions observed from the galactic microquasars GRS 1915+105 and GRO J1655-40 in practice only allow us to place lower limits on the Lorentz factors of the outflows. As a consequence, it is not…
We present a model for relativistic jets which generates a particular angular distribution of Lorentz factor and energy per solid angle. We consider a fireball with specific internal energy E/M launched with bulk Lorentz factor \gamma_B.…
We discuss results from a decade long program to study the fine-scale structure and the kinematics of relativistic AGN jets with the aim of better understanding the acceleration and collimation of the relativistic plasma forming AGN jets.…
We review the statistical properties of relativistic Doppler boosting relevant for studies of relativistic jets from compact objects based on radio--X-ray(--mass) correlations, such as that found in black-hole X-ray binaries in the low/hard…
Supermassive black holes launch highly relativistic jets with velocities reaching Lorentz factors as high as $\Gamma>50$. How the jets accelerate to such high velocities and where along the jet do they reach terminal velocity are open…
We study the variability properties at radio frequencies of the jets thought to be typical of Active Galactic Nuclei, i.e. bulk Lorentz factor \Gamma ~ 10, and incoherent synchrotron emission. We assume that the radiating electrons are…
We report the results of a 15 GHz (2 cm) multi-epoch VLBA program, begun in 1994 to study the outflow in radio jets ejected from quasars and active galaxies. The observed flow of 208 distinct features measured in 110 quasars, active…
Knowledge about the Lorentz factor and its evolution of relativistic jets in gamma-ray bursts (GRBs) is crucial to understand their physics. An exact value of bulk Lorentz factor can be estimated based on a high-energy spectral cutoff,…
In a companion paper we presented a statistical model for the blazar population, consisting of distributions for the unbeamed radio luminosity function and the Lorentz factor distribution of each of the BL Lac and Flat Spectrum Radio Quasar…
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…
The properties of wave-like helically twisted normal mode structures on steady relativistic jets are summarized. Wave speeds are a function of the wavelength and less than the jet speed. However, normal mode interference can lead to both…