Related papers: Gamma-ray burst afterglow blast waves
Gamma-Ray Bursts (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…
Physics of GRB blast waves is discussed with a focus on two effects: (1) pair creation in the external medium by the gamma-ray front and (2) decay of neutrons ahead of the decelerating blast wave. Both effects impact the afterglow mechanism…
Long gamma-ray bursts show an afterglow emission in the X-rays, optical, and radio wavelengths with luminosities that fade with time with a nearly identical power-law behavior. In this talk, I present an analytic treatment that shows that…
In order to constrain the broad-band spectral energy distribution of the afterglow of GRB 100621A, dedicated observations were performed in the optical/near-infrared with the 7-channel "Gamma-Ray Burst Optical and Near-infrared Detector"…
The Gamma-Ray burst (GRB) - afterglow transition is one of the most interesting and least studied GRB phases. During this phase the relativistic ejecta begins interacting with the surrounding matter. A strong short lived reverse shock…
The gamma-ray burst that followed the first detection of gravitational waves from the merger of a Binary Neutron Stars and its low energy counterparts were in many respects unusual and challenge our understanding of mechanisms involved in…
We investigate the intrinsic properties of a sample of bright (E_iso > 10^52 erg) gamma-ray bursts, comparing those with and without radio afterglows. We find that the sample of bursts with no radio afterglows has a significantly shorter…
We present the main observational features expected for Gamma-Ray Bursts (GRBs) that occur inside pulsar wind bubbles (PWBs). This is the most natural outcome of the supranova model, where initially a supernova (SN) explosion takes place,…
Gamma-ray bursts (GRBs) are thought to result from the interaction of an extremely relativistic outflow interacting with a small amount of material surrounding the site of the explosion. Multi-wavelength observations covering the gamma-ray…
We use published data in radio, optical and X-ray bands to analyze and model afterglows of GW/GRB 170817A. Our analysis is based on a phenomenological gamma-ray burst generator model which we previously used to study the prompt gamma-ray…
Gamma-ray bursts and their afterglows are thought to be produced by an ultra-relativistic jet. One of the most important open questions is the outflow composition: the energy may be carried out from the central source either as kinetic…
We discuss the evolution of cosmological gamma-ray burst remnants, consisting of the cooling and expanding fireball ejecta together with any swept-up external matter, after the gamma-ray event. We show that significant optical emission is…
The nearby GRB 060216/SN 2006aj was an extremely long, weak and very soft GRB. It was peculiar in many aspects. We show here that the X-ray, ultraviolet/optical and radio afterglow of GRB 060218 have to be attributed to different physical…
I show here that the time-delay between the gamma ray burst proper and the onset of the afterglow is a sensitive function of the surrounding density, going from ~10s for typical disk densities to several hours for IGM densities. Since bulk…
GRB 130925A is one of the recent additions to the growing family of ultra-long GRBs (T90$ \gtrsim 1000$ s). While the X-ray emission of ultra-long GRBs have been studied extensively in the past, no comprehensive radio dataset has been…
Long gamma-ray bursts (GRBs) are considered to be originated from core collapse of massive stars. It is believed that the afterglow property is determined by the density of the material in the surrounding interstellar medium. Therefore, the…
Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in core collapse supernova explosions (SNe). The result of the event, probably, is not just a compact object plus…
The peak time of optical afterglow may be used as a proxy to constrain the Lorentz factor Gamma of the gamma-ray burst (GRB) ejecta. We revisit this method by including bursts with optical observations that started when the afterglow flux…
A number of correlations between observables have been found to exist for gamma-ray burst (GRB) afterglows, linking ejecta energy to prompt and afterglow energy release and linking early stage optical and X-ray luminosity to the end times…
If gamma ray bursts are highly collimated, the energy requirements of each event may be reduced by several (~ 4-6) orders of magnitude, and the event rate increased correspondingly. Extreme conditions in gamma ray bursters lead to highly…