Related papers: GRB Redshift Distribution is Consistent with GRB O…
After presenting a short history of gamma-ray burst (GRB) studies, we discuss the current constraints on GRB models which follows from astronomical observations. We concentrate on the energetics of the GRBs with known redshifts and the…
There is strong evidence for the existence of black holes(BHs) in some X-ray binaries and most galatic nuclei, based on different measuremental approaches, but black holes aren't finally identified for the lack of very firm observational…
The long gamma ray bursts (GRBs) may arise from the core collapse of massive stars. However, the long GRB rate does not follow the star formation rate (SFR) at high redshifts. In this Letter, we focus on the binary merger model and consider…
Bimodal distribution of the observed duration of gamma-ray bursts (GRBs) has led to two distinct progenitors; compact star mergers, either two neutron stars (NSs) or a NS and a black hole (BH), for short GRBs (SGRBs), and so-called…
Long duration gamma-ray bursts (GRBs) accompany the deaths of some massive stars and hence, since massive stars are short lived, are a tracer of star formation activity. Given that GRBs are bright enough to be seen to very high redshifts,…
We study the luminosity function and formation rate of long gamma-ray bursts (GRBs) by using a maximum likelihood method. This is the first time this method is applied to a well-defined sample of GRBs that is complete in redshift. The…
With the discovery of gravitational waves (GWs), Active Galactic Nuclei (AGN) disks have emerged as an interesting environment for hosting a fraction of their sources. AGN disks are conducive to forming both long and short Gamma-Ray Bursts…
Recent observational and theoretical results suggest that Short-duration Gamma-Ray Bursts (SGRBs) are originated by the merger of compact binary systems of two neutron stars or a neutron star and a black hole. The observation of SGRBs with…
We compute the luminosity function (LF) and the formation rate of long gamma ray bursts (GRBs) by fitting the observed differential peak flux distribution obtained by the BATSE satellite in three different scenarios: i) GRBs follow the…
We explore galaxy properties in general and properties of host galaxies of gamma-ray bursts (GRBs) in particular, using N-body/Eulerian hydrodynamic simulations and the stellar population synthesis model, Starburst99, to infer observable…
On the ground of the large number of gamma-ray bursts (GRBs) detected with cosmological redshift, we classified GRBs in seven subclasses, all with binary progenitors originating gravitational waves (GWs). Each binary is composed by…
Gamma-ray bursts (GRBs) are violent stellar explosions that are traditionally divided into two groups: short bursts (SGRBs) with an observed duration T90 < 2 s, and long bursts (LGRBs) with an observed duration T90 > 2 s, where T90 refers…
The redshift distribution of the short-duration GRBs is a crucial, but currently fragmentary, clue to the nature of their progenitors. Here we present optical observations of nine short GRBs obtained with Gemini, Magellan, and the Hubble…
The number of supernovae known to be connected with long-duration gamma-ray bursts is increasing and the link between these events is no longer exclusively found at low redshift ($z \lesssim 0.3$) but is well established also at larger…
Short-hard Gamma Ray Bursts (SGRBs) are currently thought to arise from gravitational wave driven coalescences of double neutron star systems forming either in the field or dynamically in globular clusters. For both channels we fit the peak…
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…
We construct the Hubble diagram (HD) of Gamma-Ray Bursts (GRBs) with redshifts reaching up to $z \sim 6$, by using five luminosity vs. luminosity indicator relations calibrated with the Cardassian cosmology. This model has a major…
Long and short gamma-ray bursts are traditionally associated with galactic environments, where circumburst densities are small or moderate (few to hundreds of protons per cubic cm). However, both are also expected to occur in the disks of…
We present 10 new gamma-ray burst (GRB) redshifts and another five redshift limits based on host galaxy spectroscopy obtained as part of a large program conducted at the Very Large Telescope (VLT). The redshifts span the range 0.345 < z <…
Fast radio bursts (FRBs), millisecond-duration radio transient events, possess the potential to serve as excellent cosmological probes. The FRB redshift distribution contains information about the FRB sources, providing key constraints on…