Related papers: A note on relativistic rocketry
I review the current knowledge of high-energy emission from extragalctic jets. First I discuss gamma-ray emission from blazars, which provides us numerous precious information on the innermost portions of the relativistic jets. I describe…
We present a new derivation of the expressions for momentum and energy of a relativistic particle. In contrast to the procedures commonly adopted in textbooks, the one suggested here requires only the knowledge of the composition law for…
Though widely observed to be emanating out from a variety of galactic and extra-galactic sources, the underlying physical mechanism behind the formation of the cosmic jets and outflows are wrapped around by the veil of mystery till date.…
In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active…
Excluded-volume effects can play an important role in determining transport properties in diffusion of particles. Here, the diffusion of finite-sized hard-core interacting particles in two or three dimensions is considered systematically…
We develop a theory of particle acceleration inside relativistic rotating electron-positron force-free jets with spiral magnetic fields. We considered perturbation of the stationary magnetic field structure and found that acceleration takes…
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.…
The effect of a mass-loading of the magnetohydrodynamic (MHD) flow in a relativistic jet from active galactic nuclei (AGN) due to $\gamma\gamma\rightarrow e^+e^-$ conversion is considered analytically. We argue that the effects of charge…
Long-duration gamma-ray bursts (GRBs) require an engine capable of driving a jet of plasma to ultrarelativistic bulk Lorentz factors of up to several hundred and into narrow opening angles of a few degrees. We use global axisymmetric…
The current popular model for launching, accelerating and collimating astrophysical jets is based on magnetohydrodynamics (MHD). AGN jets are most probably powered by energy extracted from either an accretion disk or a rapidly rotating…
We revisit the concept of particles as it is used in special relativity. The presented model treats the energy-momentum relation of relativistic particles as the upper branch of a generalized energy-momentum relation of quasi particles.…
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…
I discuss recent developments in the field of relativistic jets in AGNs. After a brief review of our current knowledge of emission from Blazars, I discuss some consequences of the recent detection made by {\it Chandra} of X-ray emission…
A critical analysis of the relativistic formulation of matter reveals some surprising inconsistencies and paradoxes. Corrections are discovered which lead to the long-sought-after equality of the gravitational and inertial masses, which are…
A non--relativistic and relativistic model in which astrophysical jets are deflected on passing through an isothermal high density region is analysed. The criteria for the stability of jets due to the formation of internal shocks are…
We performed simulations of collapsars with different Kerr parameters a=0, 0.5, 0.9, 0.95. It is shown that a more rapidly rotating black hole is driving a more energetic jet. No jet is seen for the case of Schwartzschild black hole case,…
In this review article I attempt to summarise past and present-ongoing-work on the problem of the inspiral of a small body in the gravitational field of a much more massive Kerr black hole. Such extreme mass ratio systems, expected to occur…
Based on the K\"onigl's inhomogeneous jet model, we estimate the jet parameters, such as bulk Lorentz factor $\Gamma$, viewing angle $\theta$ and electron number density $n_{\rm e}$ from radio VLBI and X-ray data for a sample of active…
Within the framework of general relativity, we investigate the tidal acceleration of astrophysical jets relative to the central collapsed configuration ("Kerr source"). We neglect electromagnetic forces throughout. The rest frame of the…
The observed shift of the core of the relativistic AGN jets as a function of frequency allows us to evaluate the number density of outflowing plasma and, hence, the magnetization parameter. New analysis of more than 20 sources shows that…