Related papers: Angular Distribution of Gamma-ray Bursts and Weak …
Whilst the underlying assumption of the Friedman-Lema\^itre-Robertson-Walker (FLRW) cosmological model is that matter is homogeneously distributed throughout the universe, gravitational influences over the life of the universe have resulted…
Measurements of the two-point angular correlation function w(\theta) for 407 short gamma-ray bursts collected in the Current BATSE Catalogue reveal a ~2 \sigma deviation from isotropy on angular scales \theta ~ 2-4 degrees. Such an…
Gamma Ray Bursts (GRBs) and galaxies at high redshift represent complementary probes of the star formation history of the Universe. In fact, both the GRB rate and the galaxy luminosity density are connected to the underlying star formation.…
Gamma-ray bursts (GRBs) are the most powerful electromagnetic outbursts in the Universe and emit a vast amount of their energy in the form of gamma rays. Their duration is extremely short on cosmic timescales, but they show a wealth of time…
We revisit echelle spectra (spectral resolution R ~ 40000) of 8 Gamma-Ray Burst afterglows to obtain the incidence (dN/dz) of weak intervening Mg II systems at a mean redshift of <z> = 1.5. We show that dN/dz of systems having restframe…
We consider a gamma-ray burst (GRB) model based on an anisotropic fireball with an axisymmetric power-law distribution of the energy per solid angle with index -k, and allow for the observer's viewing direction being at an arbitrary angle…
Swift's remarkable ability to quickly localize gamma-ray bursts has led to the accumulation of a sizable burst sample for which both angular locations and redshifts are measured. This sample has become large enough that it can potentially…
Some, if not all, binary neutron star (BNS) coalescences, and a fraction of neutron - star black hole (NSBH) mergers, are thought to produce sufficient mass-ejection to power Gamma-Ray Bursts (GRBs). However, this fraction, as well as the…
Regardless of their different types of progenitors and central engines, gamma-ray bursts (GRBs) were always assumed to be standalone systems after they formed. Little attention has been paid to the possibility that a stellar companion can…
We use the weak gravitational lensing effect to study the mass distribution and dynamical state of a sample of 24 X-ray luminous clusters of galaxies ($0.05<z<0.31$) observed with the VLT-FORS1 under homogeneous sky conditions and…
We investigate the correlation of gravitational lensing of the cosmic microwave background (CMB) with several tracers of large-scale structure, including luminous red galaxies (LRGs), quasars, and radio sources. The lensing field is…
We discuss how gamma-ray burst (GRB) optical afterglows and multiwavelength observations of their host galaxies can be used to obtain information about the relative amounts of star formation happening in optical and submillimetre galaxies.…
Fast cosmological transients such as fast radio bursts (FRBs) and gamma-ray bursts (GRBs) represent a class of sources more compact than any other cosmological object. As such they are sensitive to significant magnification via…
Gamma-ray bursts (GRBs) can be probes of the early universe, but currently, only 26% of GRBs observed by the Neil Gehrels Swift Observatory GRBs have known redshifts ($z$) due to observational limitations. To address this, we estimated the…
The two closest Gamma-Ray Bursts so far detected (GRBs 980425 & 060218) were both under-luminous, spectrally soft, long duration bursts with smooth, single-peaked light curves. Only of the order of 100 GRBs have measured redshifts, and…
We compute the probability to detect long Gamma Ray Bursts (GRBs) at z>5 with Swift, assuming that GRBs form preferentially in low-metallicity environments. The model fits well both the observed BATSE and Swift GRB differential peak flux…
Gamma-ray bursts are believed to be some catastrophic event in which material is ejected at a relativistic velocity, and internal collisions within this ejecta produce the observed $\gamma$-ray flash. The angular size of a causally…
We investigate the weak gravitational lensing effect due to the large-scale structure of the universe on two-point correlations of local maxima ({\em hotspots}) in the 2D sky map of the cosmic microwave background (CMB) anisotropy.…
We study positional coincidences between gamma-ray bursts in the BATSE 3B catalogue and quasars/AGN taken from the Veron-Cetty & Veron compilation. For most classes of AGN, for BL Lac objects and for radio-loud quasars, we find no excess…
Popular models for the origin of gamma-ray bursts (GRBs) include short-lived massive stars as the progenitors of the fireballs. Hence the redshift distribution of GRBs should track the cosmic star formation rate of massive stars accurately.…