Related papers: Gamma Ray Burst and star formation rates: The phys…
Long-duration Gamma Ray Bursts (GRBs) are linked to the collapse of massive stars and their hosts are exclusively identified as active, star forming galaxies. Four long GRBs observed at high spectral resolution at redshift 1.5 <z < 4…
GRB 080913 and GRB 090423 are the most distant gamma-ray bursts (GRBs) known to-date, with spectroscopically determined redshifts of z=6.7 and z=8.1, respectively. The detection of bursts at this early epoch of the Universe significantly…
Gamma-ray burst (GRB) data suggest that the jets from GRBs in the high redshift universe are more narrowly collimated than those at lower redshifts. This implies that we detect relatively fewer long GRB progenitor systems (i.e. massive…
We compute the luminosity function (LF) and the formation rate of long gamma ray bursts (GRBs) in three different scenarios: i) GRBs follow the cosmic star formation and their LF is constant in time; ii) GRBs follow the cosmic star…
We investigate the mass distribution of long gamma-ray burst (GRB) host galaxies and the redshift distribution of long GRBs by considering that long GRBs occur in low-metallicity environments. We calculate the upper limit on the stellar…
We use population synthesis to construct distributions of gamma-ray bursts (GRBs) for different proposed progenitor models. We use a description of star formation that takes into account the evolution of metallicity with redshift and galaxy…
The gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early universe.…
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…
Recent evidence appears to link gamma-ray bursts (GRBs) to star-forming regions in galaxies at cosmological distances. If short-lived massive stars are the progenitors of GRBs, the rate of events per unit cosmological volume should be an…
A simple physical model for long-duration gamma ray bursts (GRBs) is used to fit the redshift (z) and the jet opening-angle distributions measured with earlier GRB missions and with Swift. The effect of different sensitivities for GRB…
We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity (M-Z)…
We propose to use high-redshift long $\gamma$-ray bursts (GRBs) as cosmological tools to constrain the amount of primordial non-Gaussianity in the density field. By using numerical, N-body, hydrodynamic, chemistry simulations of different…
To answer questions on the start and duration of the epoch of reionisation, periods of galaxy mergers and properties of other cosmological encounters, the cosmic star formation history (CSFH), is of fundamental importance. Using the…
Gamma Ray Bursts (GRBs) visible up to very high redshift have become attractive targets as potential new distance indicators. It is still not clear whether the relations proposed so far originate from an unknown GRB physics or result from…
We show that the time variability of a gamma-ray burst (GRB) appears to be correlated with the absolute luminosity of the burst: smooth bursts are intrinsically less luminous. This Cepheid-like relationship can be used to determine the…
Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So,…
Observations of long gamma-ray bursts (LGRBs) offer a unique opportunity for probing the cosmic star formation history, although whether or not LGRB rates are biased tracers of star formation rate history is highly debated. Based on an…
We present grids of massive star evolution models at four different metallicities (Z=0.004, 0.002, 0.001, 0.00001). The effects of rotation on the stellar structure and the transport of angular momentum and chemical elements through the…
There is now strong evidence that Long-duration Gamma-Ray Bursts (LGRBs) are preferentially formed in low-metallicity environments. However, the magnitude of this effect, and its functional dependence on metallicity have not been well…
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…