Related papers: X-ray afterglow light curves : toward standard can…
We present an analysis of early BAT and XRT data for 107 gamma--ray bursts (GRBs) observed by the Swift satellite. We use these data to examine the behaviour of the X-ray light curve and propose a classification scheme for GRBs based on…
We have collected and analyzed data taken in different spectral bands (from X-ray to optical and infrared) of the field of GRB031220 and we present results of such multiband observations. Comparison between images taken at different epochs…
Gamma ray burst (GRB) afterglow light curves have the potential to inform us about presently unobserved stages in the aftermath of a neutron star merger. Using numerical simulations of short GRB afterglows we obtain an approximate…
We present the discovery of two distinct classes in the Swift short duration gamma-ray bursts (S-GRBs) from the X-Ray Telescope (XRT) X-ray afterglow light curve. We find that about 40% of the Swift S-GRBs have an X-ray afterglow light…
Based on light curves from the Swift Burst Analyser, we investigate whether a `dip' feature commonly seen in the early-time hardness ratios of Swift-XRT data could arise from the juxtaposition of the decaying prompt emission and rising…
We present the X-ray afterglow catalog of BeppoSAX from the launch of the satellite to the end of the mission. Thirty-three X-ray afterglows were securely identified based on their fading behavior out of 39 observations. We have extracted…
Gamma-Ray Bursts can provide information about star formation at high redshifts. Even in the absence of a optical/near-infrared/radio afterglow, the high detection rate of X-ray afterglows by swift/XRT and its localization precision of 2-3…
We use a sample of 19 Gamma Ray Bursts (GRBs) that exhibit single-peaked optical light curves to test the standard fireball model by investigating the relationship between the time of the onset of the afterglow and the temporal rising…
We consider possible interpretations of the recently detected X- ray afterglow from the gamma-ray burst source GRB 970228. Cosmological and Galactic models of gamma-ray bursts predict different flux and spectral evolution of X-ray…
The redshifts of the gamma ray burst (GRB) GRB 011211 has been determined as 2.14 from several absorption lines seen in the spectrum of its optical afterglow. The spectrum of its X-ray afterglow exhibited several emission lines,and their…
We identify the fading X-ray afterglow of GRB 001025A from XMM-Newton observations obtained 1.9-2.3 days, 2 years, and 2.5 years after the burst. The non-detection of an optical counterpart to an upper limit of R=25.5, 1.20 days after the…
A significant fraction of gamma-ray bursts (GRBs) exhibit a plateau in the early X-ray afterglow light curve, whose mechanism remains uncertain. While the post-plateau normal decay index ($\alpha_2$) is commonly used to constrain the…
We reported the optical observations of GRB 121011A by 0.8-m TNT telescope at Xinglong observatory, China. The light curve of optical afterglow shows a smooth and featureless bump during the epoch of $\sim$130 sec and $\sim$5000 sec with a…
The role of the Rossi X-ray Timing Explorer (RXTE) in the study of Gamma-ray Bursts (GRBs) is reviewed. Through April 2001, the All-Sky Monitor (ASM) and the Proportional Counter Array (PCA) instruments have detected 30 GRBs. In 16 cases,…
Observations of gamma ray bursts (GRB) afterglows in different spectral bands provide a most valuable information about their nature, as well as about properties of surrounding medium. Powerful infrared afterglow was observed from the…
We test the spectral-energy correlation including the new bursts detected (mostly) by Swift with firm measurements of their redshifts and peak energy. The problem of identifying the jet breaks is discussed in the complex and…
We calculate the {\it afterglow} emission for Gamma-Ray Bursts (GRBs) going off in an extremely low density medium, referred to as {\it naked bursts}. Our results also apply to the case where the external medium density falls off sharply at…
We continue our systematic statistical study on optical afterglow data of gamma-ray bursts (GRBs). We present the apparent magnitude distributions of early optical afterglows at different epochs (t= 10^2 s, t = 10^3 s, and 1 hour) for the…
We present the first results of a program to systematically study the optical-to-X-ray spectral energy distribution (SED) of Swift GRB afterglows with known redshift. The goal is to study the properties of the GRB explosion and of the…
The temporal behaviour of the early optical emission from Gamma-Ray Burst afterglows can be divided in four classes: fast-rising with an early peak, slow-rising with a late peak, flat plateaus, and rapid decays since first measurement. The…