Related papers: Unusual Central Engine Activity in the Double Burs…
Detecting high-z GRBs is important for constraining the GRB formation rate, and tracing the history of re-ionization and metallicity of the universe. Based on the current sample of GRBs detected by Swift with known redshifts, we…
We present the gamma-ray, X-ray, optical and radio data for GRB100814A. At the end of the slow decline phase of the X-ray and optical afterglow, a sudden and prominent rebrightening in the optical band occurs followed by a fast decay in…
We present optical, X-ray and gamma-ray observations of GRB 111209A, at a redshift of z = 0.677. We show that this event was active in its prompt phase for about 25000 seconds, making it the longest burst ever observed. This rare event…
We show that the peculiar early optical and in particular X-ray afterglow emission of the short duration burst GRB 130603B can be explained by continuous energy injection into the blastwave from a supra-massive magnetar central engine. The…
Recently, triggers occurring during high background rate intervals have been reporter by Swift-BAT Gamma Ray Burst (GRB) detector. Among them, there were two on January 24, two on January 25, and two on February 13, and 18, all in 2008.…
Long duration Gamma-Ray Bursts (GRBs) originate from the core collapse of massive stars, but the identity of the central engine remains elusive. Previous work has shown that rapidly spinning, strongly magnetized proto-neutron stars…
The new and extreme population of GRBs detected by Fermi-LAT shows several new features in high energy gamma-rays that are providing interesting and unexpected clues into GRB prompt and afterglow emission mechanisms. Over the last 6 years,…
We present the analysis of two long Gamma-Ray Bursts, GRB 090323 and GRB 090328, which triggered the Fermi Gamma-Ray Burst Monitor (GBM) and generated an Autonomous Repoint Request to the Fermi Large Area Telescope. The GBM light curves…
GRB 980923 was one of the brightest bursts observed by the Burst and Transient Source Experiment (BATSE). Previous studies have detected two distinct components in addition to the main prompt episode, which is well described by a Band…
As the brightest Gamma-Ray burst (GRB) ever detected, GRB 221009A may offer a chance that reveals some interesting features which are hidden in those bursts that are not so bright. There seems a very weak emission with a flux of…
Recently, the first association between an ultra-long gamma-ray burst (GRB) and a supernova is reported, i.e., GRB 111209A/SN 2011kl, which enables us to investigate the physics of central engines or even progenitors for ultra-long GRBs. In…
To draw inferences about gamma-ray burst (GRB) source populations based on Swift observations, it is essential to understand the detection efficiency of the Swift burst alert telescope (BAT). This study considers the problem of modeling the…
IGR J11215-5952 is a hard X-ray transient source discovered in April 2005 with INTEGRAL and a confirmed member of the new class of High Mass X-ray Binaries, the Supergiant Fast X-ray Transients (SFXTs). Archival INTEGRAL data and RXTE…
The physical origin of fast radio bursts (FRBs) is still unclear. However, young magnetars associated with short-duration gamma-ray bursts (SGRBs) have been thought to be possible central engines for some FRBs. In this paper, we perform a…
We present broadband (gamma-ray, X-ray, near-infrared, optical, and radio) observations of the gamma-ray burst (GRB) 090709A and its afterglow in an effort to ascertain the origin of this high-energy transient. Previous analyses suggested…
Two separate topics are discussed. (1) We describe the classifications of the long GRB early afterglow lightcurves within the framework of the fireball shock model, focusing on the interplay between the reverse and forward shock emission…
We present the prompt BAT and afterglow XRT data of Swift-discovered GRB081109A up to ~ 5\times 10^5 sec after the trigger, and the early ground-based optical follow-ups. The temporal and spectral indices of the X-ray afterglow emission…
The majority of Swift gamma-ray bursts (GRBs) observed at z > 6 have prompt durations of T90 < 30s, which, at first sight, is surprising given that cosmological time-dilation means this corresponds to < 5s in their rest frames. We have…
The duration distribution of 947 GRBs observed by $Swift$/BAT, as well as its subsample of 347 events with measured redshift, allowing to examine the durations in both the observer and rest frames, are examined. Using a maximum…
Coherent oscillations at kilohertz frequencies have recently been detected in a small number of gamma-ray bursts (GRBs), suggesting quasi-periodic dynamics in their central engines. A prominent example is GRB~230307A, which exhibited a…