Related papers: Redshift Filtering by Swift Apparent X-ray Column …
Until 6 October 2005 sixteen redshifts have been measured of long gamma-ray bursts discovered by the Swift satellite. Further 45 redshifts have been measured of the long gamma-ray bursts discovered by other satellites. Here we perform five…
To date, the Burst Alert Telescope (BAT) onboard Swift has detected ~ 1000 gamma-ray bursts (GRBs), of which ~ 360 GRBs have redshift measurements, ranging from z = 0.03 to z = 9.38. We present the analyses of the BAT-detected GRBs for the…
The high-redshift star formation rate (SFR) is difficult to measure directly even by modern approaches. Long-duration gamma-ray bursts (GRBs) can be detected to the edge of the visible universe because of their high luminorsities. The…
(abridged) We present a new sample of X-ray selected galaxy groups and clusters serendipitously observed with Swift and the X-ray Telescope (XRT). We searched the XRT archive for extended sources among 336 GRB fields with galactic latitude…
The exceptionally high luminosities of gamma-ray bursts (GRBs), gradually emerging as extremely useful probes of star formation, make them promising tools for exploration of the high-redshift Universe. Here we present a carefully selected…
Long-duration Gamma-Ray Bursts (GRBs) allow us to pinpoint and study star-forming galaxies in the early universe, thanks to their orders of magnitude brighter peak luminosities compared to other astrophysical sources, and their association…
Several claims have been put forward that an essential fraction of long-duration BATSE gamma-ray bursts should lie at redshifts larger than 5. This point-of-view follows from the natural assumption that fainter objects should, on average,…
We apply the Lyman absorption signature to search for galaxies at redshifts z \~ 6 - 17 using optical and infrared images of the Hubble Deep Field. The infrared images are sensitive to a point source 5 sigma detection threshold of…
Unlike the neutral gas density, which remains largely constant over redshifts of 0 < z < 5, the star formation density exhibits a strong redshift dependence, increasing from the present day before peaking at a redshift of z ~ 2.5. Thus,…
The optical afterglow spectrum of GRB050401 (at z=2.8992+/-0.0004) shows the presence of a DLA, with log(nHI)=22.6+/-0.3. This is the highest column density ever observed in a DLA, and is about five times larger than the strongest DLA…
We interpret the large variety of redshift distributions of galaxies found by far-infrared and (sub-)millimeter deep surveys depending on their depth and wavelength using the B\'ethermin et al. (2012) phenomenological model of galaxy…
We measured the galactic hydrogen column densities to the neutron-star binaries GX 17+2, 4U 1705-44, and 4U 1728-34 by modeling the Mg and Si absorption edges found in high-resolution X-ray spectra obtained by the Chandra X-ray Observatory.…
We study the properties of the population of optically dark events present in a carefully selected complete sample of bright Swift long gamma-ray bursts. The high level of completeness in redshift of our sample (52 objects out of 58) allow…
In this work, we update and enlarge the long gamma-ray burst (GRB) sample detected by the {\it Swift} satellite. Given the incomplete sampling of the faint bursts and the low completeness in redshift measurement, we carefully select a…
Using a sample of gamma-ray burst (GRB) afterglows detected by both the X-Ray and the UV/Optical Telescopes (XRT and UVOT) on Swift, we modelled the spectral energy distributions (SEDs) to determine gas column densities and dust extinction…
Utilizing more than 100 long gamma-ray bursts (LGRBs) in the Swift-Ryan-2012 sample that include the observed redshifts and jet angles, Le & Mehta performed a timely study of the rate-density of LGRBs with an assumed broken power law GRB…
The equation of state for ultra-dense matter can be tested from observations of the ratio of mass to radius of neutron stars. This could be measured precisely from the redshift of a narrow line produced on the surface. X-rays bursts have…
We study the evolution with redshift of three measures of gamma-ray burst (GRB) duration ($T_{\rm 90}$, $T_{\rm 50}$ and $T_{\rm R45}$) in a fixed rest frame energy band for a sample of 232 Swift/BAT detected GRBs. Binning the data in…
This paper addresses the problem of detecting high-redshift clustering in deep photometric surveys. We have used photometric redshifts to select different samples of galaxies in the HDF, in order to study their clustering properties within…
Long Gamma Ray Bursts hold the promise of probing star-formation and metal enrichment up to very high redshifts. The present GRB samples with redshift determination are largely incomplete and therefore a careful analysis of selection…