Related papers: Relativistic jets at high energies
Gamma-ray bursts (GRBs) are luminous stellar explosions characterized by the ejection of relativistic jets. This work proposes a novel paradigm to study these GRB jets. By analyzing the timing information of prompt pulses and X-ray flares,…
Afterglow radiation in gamma-ray bursts (GRB), extending from the radio band to GeV energies, is produced as a result of the interaction between the relativistic jet and the ambient medium. Although in general the origin of the emission is…
High velocity highly collimated beams of plasma -- the jets -- are known as a general phenomenon among astrophysical sources of different energy and spatial scale. The common MHD scenario of astrophysical jet formation allows to describe…
We study the possible detection of and properties of very high-energy (VHE) gamma-ray emission (in the energy band above 100 GeV) from high redshift sources. We report on the detection of VHE gamma-ray flux from blazars with redshifts…
We discuss the implications of Fermi/LAT observations on several aspects of gamma-ray burst (GRB) physics, including the radiation process, the emission sites, the bulk Lorentz factor, and the pre-shock magnetic field: (1) MeV-range…
Radio Galaxies have by now emerged as a new $\gamma$-ray emitting source class on the extragalactic sky. Given their remarkable observed characteristics, such as unusual gamma-ray spectra or ultrafast VHE variability, they represent unique…
Recent observations in the TeV band challenge the simplest models developed to describe the overall emission of blazars and radiogalaxies. In particular, the observation of variable TeV emission from M87 and the fast variability shown by…
Blazars are the most plentiful gamma-ray source at GeV energies, and despite detailed study, there is much that is not known about these sources. In this review I explore some recent results on blazars, including the controversy of the…
In many theoretical models of gamma-ray bursts (GRBs) and their afterglows, the emission of photons above 100 GeV is predicted. The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope has detected delayed, high-energy…
Some highlights of the recent researches in the field of relativistic jets are reviewed and critically analyzed. Given the extent of the available literature, this essay symbolically takes the baton from the outstanding and recent review by…
Rapid variability of the TeV emission in several blazars implies a central black hole mass $M_{BH}<10^8M_\odot$, appreciably smaller than the values estimated from the $M_{BH}-L_{bulg}$ relation, and Doppler factors for the $\gamma$-ray…
The X-ray emission of gamma-ray bursts (GRBs) is often characterized by an initial steep decay, followed by a nearly constant emission phase (so called "plateau") which can extend up to thousands of seconds. While the steep decay is usually…
In the current view of Gamma-Ray Burst (GRB) phenomena, an emission component extending up to the very-high energy (VHE, E > 30 GeV) domain is though to be a relatively common feature at least in the brightest events. This leads to an…
Models of relativistic jets filled with ultrarelativistic pair plasma are very successful in explaining the broadband radiation of $\gamma$-ray blazars. Assuming that the initial injection and cooling of ultrarelativistic pair plasma in an…
Ultrarelativistic jets are believed to play an important role in producing prompt emission and afterglow of gamma-ray bursts (GRBs), but the nature of the jet is poorly known owing to the lack of decisive features observed in the prompt…
Emission from astronomical jets extend over the entire spectral band: from radio to the TeV gamma-rays. This implies that various radiative processes are taking place in different regions along jets. Understanding the origin of the emission…
We review the recent observational results of the gamma-ray linear polarization of Gamma-Ray Bursts (GRBs), and discuss some theoretical implications for the prompt emission mechanism and the magnetic composition of GRB jets. We also report…
We consider a model in which the ultra-relativistic jet in a gamma-ray burst (GRB) is cold and magnetically accelerated. We assume that the energy flux in the outflowing material is partially thermalized via internal shocks or a reverse…
This is a report on the findings of the gamma ray burst working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released…
High-energy gamma-ray (>GeV) emission of gamma-ray bursts (GRBs) is very important in probing the jet evolution and particle acceleration of GRBs. The observations of high-energy photons are limited except for a few very bright GRBs,…