Related papers: Observational difference between gamma and X-ray p…

Some short gamma-ray bursts (SGRBs) exhibit a short duration and spectral hard emission (referred to as a "hard spike") followed by a slightly longer soft emission (known as a "soft tail"). We identified nine SGRBs with known redshift in…

The unrivalled, extreme luminosities of gamma-ray bursts (GRBs) make them the favored beacons for sampling the high redshift Universe. To employ GRBs to study the cosmic terrain -- e.g., star and galaxy formation history -- GRB luminosities…

Supergiant Fast X-ray Transients (SFXT) are High Mass X-ray Binaries displaying X-ray outbursts reaching peak luminosities of 10$^{38}$ erg/s and spend most of their life in more quiescent states with luminosities as low as…

We describe and discuss the spectral and temporal characteristics of the prompt emission and X-ray afterglow emission of X-ray flashes (XRFs) and X-ray-rich gamma-ray bursts (XRRs) detected and observed by Swift between December 2004 and…

We present the discovery of the optical transient of the long-duration gamma-ray burst GRB000630. The optical transient was detected with the Nordic Optical Telescope 21.1 hours after the burst. At the time of discovery the magnitude of the…

Optical, infrared and ultraviolet observations of GRB fields have allowed detection of counterparts and host galaxies of the high energy transients, thus crucially contributing to our present knowledge of the GRB phenomenon. Measurements of…

Thanks to the rapid position notice and response by HETE-2 and Swift, the X-ray afterglow emissions have been found for four recent short gamma-ray bursts (GRBs; GRB 050509b, GRB 050709, GRB 050724, and GRB 050813). The positions of three…

We compare the luminosity function and rate inferred from the GBM long bursts peak flux distribution with those inferred from the Swift and BATSE peak flux distribution. We find that the GBM, BATSE and the Swift peak fluxes can be fitted by…

Following a brief introduction we show that the observations obtained so far with the Swift satellite begin to shed light over a variety of problems that were left open following the excellent performance and related discoveries of the…

X-ray flares of gamma-ray bursts (GRBs) are usually observed in the soft X-ray range and the spectral coverage is limited. In this paper, we present an analysis of 32 GRB X-ray flares that are simultaneously observed by both BAT and XRT on…

We have computed the luminosity rest frame light curves of the first 40 Gamma-ray bursts (GRBs) detected by Swift with well established redshift. We studied average properties of the light curves in the four subsamples of bursts given by…

There have now been three supernova-associated gamma-ray bursts (GRBs) at redshift z < 0.17, namely 980425, 030329, and 031203, but the nearby and under-luminous GRBs 980425 and 031203 are distinctly different from the `classical' or…

We use joint observations by the Neil Gehrels Swift X-ray Telescope (XRT) and the Fermi Large Area Telescope (LAT) of gamma-ray burst (GRB) afterglows to investigate the nature of the long-lived high-energy emission observed by Fermi LAT.…

We have observed four low-luminosity active galactic nuclei classified as Type 1 LINERs with the X-ray Telescope (XRT) and the UltraViolet-Optical Telescope (UVOT) onboard Swift, in an attempt to clarify the main powering mechanism of this…

We compare mid-infrared emission-line properties, from high-resolution Spitzer spectra of a hard X-ray (14 -- 195 keV) selected sample of nearby (z < 0.05) AGN detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity…

We imaged the error box of a gamma-ray burst of the short (0.5 s), hard type (GRB 000313), with the BOOTES-1 experiment in southern Spain, starting 4 min after the gamma-ray event, in the I-band. A bright optical transient (OT 000313) with…

We present the results of our study of the variability time scales of a sample of 27 long Swift Gamma-Ray Bursts (GRBs) with known redshifts. The variability time scale can help our understanding of fundamental GRB parameters such as the…

Highly luminous rapid flares are characteristic of processes around compact objects like white dwarfs, neutron stars or black holes. In the high energy regime of X- and gamma-rays, outbursts with variability time-scales of seconds and…

A considerable fraction of incident high-energy photons from astrophysical transients such as Gamma-Ray Bursts (GRBs) is Compton scattered by the Earth's atmosphere. These photons, sometimes referred to as the "reflection component",…

The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a…