Related papers: Generalized equipartition method from an arbitrary…
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…
We report the detection of linear polarization from SgrA* at 750, 850, 1350 and 2000 microns which confirms the contribution of synchrotron radiation. From the lack of polarization at longer wavelengths it appears to arise in the…
We show that observed properties of the low luminosity GRB171205A and its afterglow, like those of most other low-luminosity (LL) gamma ray bursts (GRBs) associate with a supernova (SN), indicate that it is an ordinary SN-GRB, which was…
We apply relativistic equipartition synchrotron arguments to the radio data of the tidal disruption event candidate Sw 1644+57. We find that, regardless of the details of the equipartition scenario considered, the energy required to produce…
Using a large set of optically detected hotspots in powerful extragalactic double radio sources, we examine the basic question of whether the detection of optical synchrotron radiation requires in-situ acceleration of relativistic electrons…
We discuss the possibility of observing distant accelerators of ultra high energy cosmic rays in synchrotron gamma rays. Protons propagating away from their acceleration sites produce extremely energetic electrons during photo-pion…
GRB 990123 is the most luminous event detected so far, and in an important paper, Hjorth et al. (1999) reported an upper limit on the degree of linear polarization of the optical afterglow for this burst (P <2.3%). One of the interprtations…
Electromagnetic observations of the first binary Neutron Star (BNS) merger GW170817 has established that relativistic jets can be successfully launched in BNS mergers. Typically, such jets produce emission in two phases: $\gamma$-ray prompt…
Gamma-ray burst (GRB) jets are narrow, and thus typically point away from us. They are initially ultra-relativistic, causing their prompt $\gamma$-ray and early afterglow emission to be beamed away from us. However, as the jet gradually…
The coherent reflectivity of a dense, relativistic, ultra-thin electron layer is derived analytically for an obliquely incident probe beam. Results are obtained by two-fold Lorentz transformation. For the analytical treatment, a plane…
A subset of the unidentified EGRET gamma-ray sources with no active galactic nucleus or other conspicuous counterpart appears to be concentrated at medium latitudes. Their long-term variability and their spatial distribution indicate that…
Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal…
In the unified scheme FR I type radio galaxies are identified with the blazar type active galaxies which jets are aligned at large angles to the line of sight. A few radio galaxies of this type have been discovered to emit GeV-TeV…
A model is developed for the time dependent electromagnetic - radio to gamma-ray - emission of active galactic nuclei, specifically, the blazars, based on the acceleration and creation of leptons at a propagating discontinuity or {\it…
The Laser Interferometer Space Antenna (LISA) will operate as an AM/FM receiver for gravitational waves. For binary systems, the source location, orientation and orbital phase are encoded in the amplitude and frequency modulation. The same…
Early optical afterglows have been observed from GRB 990123, GRB 021004, and GRB 021211, which reveal rich emission features attributed to reverse shocks. It is expected that Swift will discover many more early afterglows. Here we…
The multiwavelength spectra of PKS 0528+134 during six years of observations by EGRET have been analyzed using synchrotron self-Compton (SSC) and external radiation Compton (ERC) models. We find that a two-component model, in which the…
Blazars, a subset of powerful active galactic nuclei, feature relativistic jets that shine in a broadband electromagnetic radiation, e. g. from radio to TeV emission. Here I present the results of the studies that explore gamma-ray and…
The all-sky survey in high-energy gamma rays (E$>$30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma-Ray Observatory provides a unique opportunity to examine in detail the diffuse gamma-ray…
Chandra observations of knots and hot spots in spatially resolved X-ray jets of radio galaxies show that the X-ray fluxes often lie above an extrapolation from the radio-to-optical continuum fluxes. We show that combined synchrotron and…