Related papers: Where are the missing gamma ray burst redshifts?

We predict the redshift of the first observable (i.e., in our past light cone) Gamma Ray Burst (GRB) and calculate the GRB-rate redshift distribution of the Population III stars at very early times (z=20-60). Using the last 2 years of data…

We present the redshift results from a Very Large Telescope program aimed at optimizing the legacy value of the Swift mission: to characterize a homogeneous, X-ray selected, sample of 69 GRB host galaxies. 19 new redshifts have been…

It is known that the soft tail of the gamma-ray bursts' spectra show excesses from the exact power-law dependence. In this article we show that this departure can be detected in the peak flux ratios of different BATSE DISCSC energy…

Gamma-ray bursts (GRBs) are cosmologically distributed, very energetic and very transient sources detected in the gamma-ray domain. The identification of their x-ray and optical afterglows allowed so far the redshift measurement of 150…

We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey ("SHOALS"), a multi-observatory high-redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst hosts yet assembled (119 in total). We…

Presently only 30% of short gamma ray bursts (SGRBs) have accurate redshifts, and this sample is highly biased by the limited sensitivity of {\it Swift} to detect SGRBs. We account for the dominant biases to calculate a realistic SGRB rate…

We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite during the years 2005-2009, representing all GRBs with an unambiguous host-frame extinction of…

A significant fraction (30\%) of well-localized short gamma-ray bursts (sGRBs) lack a coincident host galaxy. This leads to two main scenarios: \textit{i}) that the progenitor system merged outside of the visible light of its host, or…

[Abridged] We present data and initial results from VLT/X-Shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1<z<3.6, the largest sample of GRB host spectroscopy available to date. Most of our GRBs were detected by Swift…

Ten years of operations of the Swift satellite have allow us to collect a small sample of long Gamma-Ray Bursts (GRBs) at redshift larger than six. I will review here the present status of this research field and discuss the possible use of…

We present a detailed analysis of the selection effects that plague GRB observations. We find that these effects may partially explain the different redshift distributions between BeppoSax/HETE2 and Swift bursts. It is mandatory to consider…

The relation between the event rate of long Gamma-Ray Bursts at low redshift and the star formation rate is still controversial, especially in the low-redshift end. Dong et al. confirmed that the Gamma-Ray Burst rate always exceeds the star…

Swift/BAT has detected ~ 200 long-duration GRBs, with redshift measurements for ~50 of them. We derive the luminosity function (Phi^{HL}) and the local event rate (rho_0^{HL}) of the conventional high luminosity (HL) GRBs by using the…

We invert directly the redshift - luminosity distribution of observed long Swift GRBs to obtain their rate and luminosity function. Our best fit rate is described by a broken power law that rises like (1+z)^2.1{+0.5-0.6} for 0<z<3 and…

A good fraction of GRBs detected by Swift are at a large redshift (up to z=6.3, so far). Their study allows us to investigate, among other things, the cosmic star formation in the early Universe (possibly up to the re-ionization era) and…

Using the sample of long Gamma-ray bursts (GRBs) detected by Swift-BAT before June 2007, we measure the cumulative distribution of the peak photon fluxes (log N - log P) of the Swift bursts. Compared with the BATSE sample, we find that the…

We propose a redshift estimator for the long ($T_{90} > 20$) gamma-ray bursts (GRBs) observed by the BATSE. It is based on an empirical relation between the redshift and the power-law index of power density spectra (PDSs) of the observed…

If Gamma-Ray-Bursts (GRBs) occur at high redshifts, then their bright afterglow emission can be used to probe the ionization and metal enrichment histories of the intervening intergalactic medium during the epoch of reionization. In…

We compare the properties of optically dark GRBs, defined by the optical-to-X-ray spectral index beta_OX<0.5, and normal ones discovered by the Swift satellite before the year 2008 in a statistical way, using data collected from the…

In this work, we restudy the dependence of luminosity function and event rates for different gamma-ray burst samples on the criteria of sample selection and threshold effect. To compare with many previous studies, we have chosen two samples…