Related papers: Duration distributions for different softness grou…
We propose a redshift estimator for the long ($T_{90} > 20$) gamma-ray bursts (GRBs) observed by the BATSE. It is based on an empirical relation between the redshift and the power-law index of power density spectra (PDSs) of the observed…
The gamma-ray bursts detected by the BATSE instrument may be separated into "short", "intermediate" and "long" subgroups. Previous statistical tests found an anisotropic sky-distribution on large angular scales for the intermediate…
We argue that the distributions of both the intrinsic fluence and the intrinsic duration of the gamma-ray emission in gamma-ray bursts from the BATSE sample are well represented by log-normal distributions, in which the intrinsic dispersion…
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…
We analyze pulse properties of Short gamma-ray bursts (GRBs) from a new catalog containing 434 pulses from 387 BATSE Time-Tagged Event (TTE) GRBs. Short GRB pulses exhibit correlated properties of duration, fluence, hardness, and amplitude,…
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…
Power density spectra (PDSs) of long gamma-ray bursts (GRBs) provide useful information on GRBs, indicating their self-similar temporal structure. The best power-law PDSs are displayed by the longest bursts (T_90>100 s) in which the range…
We propose a possible unified model of short and long gamma-ray bursts (GRBs), X-ray rich GRBs, and X-ray flashes. The jet of a GRB is assumed to consist of multiple sub-jets or sub-shells (i.e., an inhomogeneous jet model). The…
The analysis of the BATSE's count distribution within cosmological models suffers from observational uncertainties due to the variability of the bursts' spectra: when BATSE observes bursts from different redshifts at a fixed energy band it…
The variety of long duration gamma-ray burst (LGRB) light curves (LCs) encode a wealth of information on how LGRB engines release energy following the collapse of the progenitor star. Attempts to characterise GRB LCs focused on a number of…
We study the spectra of short-bright GRBs detected by BATSE and compare them with the average and time resolved spectral properties of long-bright bursts. We confirm that short events are harder than long bursts, as already found from the…
Different forms of long gamma-ray bursts (GRBs) Luminosity Functions are considered on the basis of an explicit physical model. The inferred flux distributions are compared with the observed ones from two samples of GRBs, Swift and Fermi…
In this paper, we examine the spacial distribution of gamma-ray bursts (GRBs) using a sample of 373 objects. We subdivide the GRB data into two redshift intervals over the redshift range $0<z< 6.7$. We measure the two-point correlation…
We present here our results of the temporal and spectral analysis of a sample of 52 bright and hard gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) during its first year of operation (July 2008-July 2009). Our…
Long gamma-ray bursts (GRBs) frequently exhibit complex prompt emission structures with multiple temporally distinct episodes, such as a main emission (ME) phase followed by a weak extended emission (EE) tail. Whether these subcomponents…
The intermediate-duration gamma-ray bursts (GRBs) identified in the data of the RHESSI satellite are investigated with respect to their spectral lags, peak count rates, redshifts, supernova observations, and star formation rates of their…
Gamma-ray bursts (GRBs) are intense, short-lived bursts of gamma-ray radiation observed up to a high redshift ($z \sim 10$) due to their luminosities. Thus, they can serve as cosmological tools to probe the early Universe. However, we need…
Preliminary results of our analysis on the extended emission of short/medium duration GRBs observed with Swift/BAT are presented. The Bayesian blocks algorithm is used to analyze the burst durations and the temporal structure of the…
Classification of gamma-ray bursts (GRBs) has been a long-standing puzzle in high-energy astrophysics. Recent observations challenge the traditional short vs. long viewpoint, where long GRBs are thought to originate from the collapse of…
The BeppoSAX Catalog has been very recently published. In this paper we analyze - using the Maximum Likelihood (ML) method - the duration distribution of the 1003 GRBs listed in the catalog with duration. The ML method can identify the long…