Related papers: Beaming Selection and SN-GRB-Jets Evolution
Observational consequences of a jet-driven supernova (SN) explosion model are presented. The results are compared in detail with optical observations of SN 1998bw associated with a Gamma-Ray Burst. It is shown that the jet model is able to…
The first neutron star binary merger detected in gravitational waves, GW170817 and the subsequent detection of its emission across the electromagnetic spectrum showed that these systems are viable progenitors of short $\gamma$-ray bursts…
The issue of the possible presence or absence of jets in GRBs is here re-examined for GRB991216. We compare and contrast our theoretically predicted afterglow luminosity in the 2-10 keV band for spherically symmetric versus jetted emission.…
Compact binary mergers, with neutron stars or neutron star and black-hole components, are thought to produce various electromagnetic counterparts: short gamma-ray bursts (GRBs) from ultra-relativistic jets followed by broadband afterglow;…
Recent studies suggest that when cold nuclear matter is compressed to high nuclear densities, diquarks with spin zero and antisymmetric color wave function Bose condensate into a superfluid/superconducting state that is several times as…
Gamma-Ray Bursts are the most luminous events in the Universe, and are excellent laboratories to study extreme physical phenomena in the cosmos. Despite a long trajectory of progress in understanding these highly energetic events, there are…
(Abridged) SN 2002ap is an interesting event with broad spectral features like the famous SN 1998bw / GRB 980425. Here we examine the recently proposed jet hypothesis from SN 2002ap by a spectropolarimetric observation. We show that jets…
There are several lines of evidence which suggest that the relativistic outflows in gamma-ray bursts (GRBs) are collimated into narrow jets. The jet structure has important implications for the true energy release and the event rate of…
In order to assist in planing the search of supernova (SN) in the late time afterglow (AG) of the gamma ray burst (GRB) 011121 we use the Cannonball Model of GRBs and the observations of its afterglow in the R band in the first two days to…
There was a bright, transient companion spot to SN1987A with a projected distance of about 17 light-days, observed by optical speckle interferometry one to two months after explosion. It is shown here that the bright spot may be due to a…
Short-duration gamma-ray bursts (SGRBs) are intense flashes of cosmic gamma-rays, lasting less than ~2 s, whose origin is one of the great unsolved questions of astrophysics today. While the favoured hypothesis for their production, a…
Gamma-ray bursts (GRB) are sudden, intense flashes of gamma-rays which, for a few blinding seconds, light up in an otherwise fairly dark gamma-ray sky. They are detected at the rate of about once a day, and while they are on, they outshine…
Four years after the launch the Swift satellite the nature of the GRBs broadband afterglow behaviour is still an open issue. The standard external shock fireball model cannot easily explain the combined temporal and spectral properties of…
Using the 2.4m MDM and 8.4m Large Binocular Telescope, we observed nine GRB afterglows to systematically probe the late time behaviors of afterglows including jet breaks, flares, and supernova bumps. In particular, the LBT observations have…
The recent discovery of a faint gamma-ray burst (GRB) coincident with the gravitational wave (GW) event GW 170817 revealed the existence of a population of low-luminosity short duration gamma-ray transients produced by neutron star mergers…
SN 2001em, identified as a Type Ic supernova, has recently been detected in the radio and X-rays, $\gtrsim$ 2 yr after the explosion. The high luminosities at such late times might arise from a relativistic jet viewed substantially off-axis…
GRBs have remained a puzzle for many high-energy astrophysicists since their discovery in 1967. With the advent of the X-ray satellites BeppoSAX and RossiXTE, it has been possible to carry out deep multi-wavelength observations of the…
This article gives a brief historical introduction and reviews our current understanding of jets in radio galaxies and quasars from an observational perspective, with an emphasis on observations at radio wavelengths. Recent results on the…
GRB 160821B is a short duration gamma-ray burst (GRB) detected and localized by the Neil Gehrels Swift Observatory in the outskirts of a spiral galaxy at z=0.1613, at a projected physical offset of 16 kpc from the galaxy's center. We…
Metal-poor massive stars may typically end up their lives as blue supergiants (BSGs). Gamma-ray bursts (GRBs) from such progenitors could have ultra-long duration of relativistic jets. For example Population III (Pop III) GRBs at z ~ 10-20…