Related papers: GRBs Light Curves - Another Clue on the Inner Engi…
Gamma ray bursts (GRBs) are short and intense pulses of $\gamma$-rays arriving from random directions in the sky. Several years ago Amelino-Camelia et al. pointed out that a comparison of time of arrival of photons at different energies…
The GRB central engine intrinsic activity time $T_{\rm ce}$ is usually described through either the $\gamma$-ray duration $T_{90}$ or through a generalized burst duration $t_{\rm burst}$ which includes both the $\gamma$-ray emission and…
The internal shock model for gamma-ray bursts involves shocks taking place in a relativistic wind with a very inhomogeneous initial distribution of the Lorentz factor. We have developed a 1D lagrangian hydrocode to follow the evolution of…
We present a detail analysis on the spectral lags of the short gamma-ray bursts (GRBs) and compare them with that of the long GRBs by using the CGRO/BATSE GRB Catalog. Our results are as follows. (1)The spectral lag distribution of the…
We study the power density spectrum (PDS) of artificial light curves of observed gamma-ray bursts (GRBs). We investigate statistical properties of GRB light curves by comparing the reported characteristics in the PDSs of the observed GRBs…
Gamma-Ray Bursts (GRBs), short and intense pulses of low energy gamma-rays, have fascinated astronomers and astrophysicists since their unexpected discovery in the late sixties. During the last decade, several space missions: BATSE (Burst…
Among the models used to explain the prompt emission of gamma-ray bursts (GRBs), internal shocks is a leading one. Its most basic ingredient is a collision between two cold shells of different Lorentz factors in an ultra-relativistic…
The recent localization of some short-hard gamma ray bursts (GRBs) in galaxies with low star formation rates has lent support to the suggestion that these events result from compact object binary mergers. We discuss how new simulations in…
Recently, several new correlations between the observed $\gamma$-ray and the X-ray properties of gamma-ray bursts (GRBs) were inferred from a comprehensive analysis of the X-ray light curves of more than 650 GRBs measured with the Swift…
According to the internal-external shocks model for $\gamma $-ray bursts (GRBs), the GRB is produced by internal shocks within a relativistic flow while the afterglow is produced by external shocks with the ISM. We explore the early…
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…
There are several lines of evidence indicating that the ultra-relativistic outflows powering gamma-ray bursts (GRBs) are collimated into narrow jets. However, these are indirect, and the jet structure is rather poorly constrained. What is…
Both gamma-ray bursts (GRBs) and blazars have relativistic jets pointing at a small angle from our line of sight. Several recent studies suggested that these two kinds of sources may share similar jet physics. In this work, we explore the…
In spite of the complicated behavior in the time domain, long GRBs show a simpler behavior in the Fourier domain of frequencies, represented by power density spectra, PDS. Recently, there are some relations found between GRBs properties and…
We consider some recent developments in GRB/afterglow observations: (i) the appearance of a very hard prompt component in GRB 941017, and (ii) variability in the early afterglow light curves of GRB 021004 and GRB 030329. We show that these…
Gamma-ray bursts (GRBs), the brightest electromagnetic bursts in the universe, are believed to originate from ultra-relativistic jets launched by the rapidly rotating central engine, either a disk-surrounded newly formed black hole (BH) or…
We perform a statistical analysis of the temporal structure of long Gamma-Ray-Bursts (GRBs). First we consider a sample of bursts in which a long quiescent time is present. Comparing the pre-quiescence with the post-quiescence emission we…
We calculate the synchrotron self-Compton emission from internal shocks occurring in relativistic winds as a source of gamma-ray bursts, with allowance for self-absorption. For plausible model parameters most pulses within a Gamma-Ray Burst…
The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain…
We examine a sample of 48 Swift/UVOT long Gamma-ray Burst light curves and find a correlation between the logarithmic luminosity at 200s and average decay rate determined from 200s onwards, with a Spearman rank coefficient of -0.58 at a…