相关论文: The true redshift distribution of Pre-SWIFT gamma-…

X-Ray Flashes (XRFs) are soft gamma-ray bursts whose nature is not clear. Their soft spectrum can be due to cosmological effects (high redshift), an off-axis view of the jet or can be intrinsic to the source. We use SWIFT observations to…

The redshift distribution of gamma-ray bursts (GRBs) is strongly biased by selection effects. We investigate, via Monte Carlo simulations, one possible selection effect that may be modifying the Swift GRB redshift distribution. We show how…

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…

We predict the redshift distribution of Gamma-Ray Bursts (GRBs) assuming that they trace the cosmic star formation history. We find that a fraction >~50% of all GRBs on the sky originate at a redshift z >~5, even though the fraction of the…

We employ realistic constraints on astrophysical and instrumental selection effects to model the Gamma-Ray Burst (GRB) redshift distribution using {\it Swift} triggered redshift samples acquired from optical afterglows (OA) and the TOUGH…

We studied the optical afterglows of the 24 pre-Swift Gamma-Ray Bursts with known spectroscopic redshift and published estimates of the optical extinction in the source frame. We find an unexpected clustering of the optical afterglow…

We employ realistic constraints on selection effects to model the Gamma-Ray Burst (GRB) redshift distribution using {\it Swift} triggered redshift samples acquired from optical afterglows and the TOUGH survey. Models for the Malmquist bias,…

We predict the redshift distribution of long Gamma-Ray Bursts (GRBs) with Monte Carlo simulations. Our improved analysis constrains free parameters with three kinds of observation: (i) the log(N)-log(P) diagram of BATSE bursts; (ii) the…

We studied the behaviour of the optical afterglow lightcurves of a sample of 24 Gamma--Ray Bursts (GRBs) with known redshift and published estimates of the optical extinction in the source frame, detected before the SWIFT satellite launch.…

The extreme luminosity of gamma-ray bursts (GRBs) and their afterglows means they are detectable, in principle, to very high redshifts. Although the redshift distribution of GRBs is difficult to determine, due to incompleteness of present…

The distance scale to gamma ray bursts has been a subject of scientific debate for almost thirty years. Up to the discovery of afterglows only indirect methods could be used to constrain the distance scale to this objects. I review some of…

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…

The detection of x-ray afterglows of gamma-ray burst (GRB) sources has enabled the optical discovery that GRBs are at cosmological distances, which confirms that the enormous luminosities required must produce a relativistically expanding…

We investigate the clustering of afterglow light curves observed at X-ray and optical wavelengths. We have constructed a sample of 61 bursts with known dis tance and X-ray afterglow. This sample includes bursts observed by BeppoSAX,…

Gamma-ray bursts are promising tools for tracing the formation of high redshift stars, including the first generation. At very high redshifts the reverse shock emission lasts longer in the observer frame, and its importance for detection…

It is clear that optical selection effects have distorted the "true" GRB redshift distribution to its presently observed biased distribution. We constrain a statistically optimal model that implies GRB host galaxy dust extinction could…

The measured redshifts of gamma-ray bursts (GRBs), which were first detected by the Swift satellite, seem to be bigger on average than the redshifts of GRBs detected by other satellites. We analyzed the redshift distribution of GRBs…

Gamma-ray bursts (GRBs) are spectacularly energetic events, with the potential to inform on the early universe and its evolution, once their redshifts are known. Unfortunately, determining redshifts is a painstaking procedure requiring…

Context: Thirteen years after the discovery of the first afterglows, the nature of dark gamma-ray bursts (GRB) still eludes explanation: while each ng-duration GRB typically has an X-ray afterglow, optical/NIR emission is only seen for…

One of the most important task of the Gamma-Ray Burst field is the classification of the bursts. Many researches have proven the existence of the third kind (intermediate duration) of GRBs in the BATSE data. Recent works have analyzed…