Related papers: Gamma-Ray Bursts as a Cosmic Window for Galaxy Evo…
Cosmological gamma ray bursts (GRBs) are the brightest explosions in the Universe. Satellite detectors, such as Beppo-SAX, HETE2 and more recently Swift, have provided a wealth of data, including the localization and redshifts of subsets of…
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…
Highly relativistic jets from merger and accretion induced collapse of compact stellar objects, which may produce the cosmological gamma ray bursts (GRBs), are also very efficient and powerful cosmic ray accelerators. The expected…
The last decade has been dense with new developments in the search for the sources of Galactic cosmic rays. Some of these developments have confirmed the tight connection between cosmic rays and supernovae in our Galaxy, through the…
Gamma-ray bursts are sudden releases of energy that for a duration of a few seconds outshine even huge galaxies. 30 years after the first detection of a gamma-ray burst their origin remains a mystery. Here I first review the ``old''…
Galaxies are key objects for the study of cosmology, the life cycle of matter, and stellar evolution. X-ray observations have given us a new key window into these building blocks of the Universe, that allows us to investigate their hot…
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…
Long-duration gamma-ray bursts(LGRBs) are believed to be linked with the star formation. We adopt a galactic evolution model, in which the star formation process inside the virialized dark halo at given redshift can be achieved. In this…
The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in…
Gamma-ray bursts and ultra-high-energy cosmic rays provide an important testing ground for fundamental physics. A simple-minded analysis of some gamma-ray bursts would lead to a huge estimate of the overall energy emitted, and this…
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 investigate the effects of primordial non-Gaussianities in the primordial Universe on the baryonic structure formation process. By relating the cosmic star formation rate in Gaussian and non-Gaussian scenarios to the detectability of…
Gamma-ray bursts (GRBs) are among the most energetic events in the universe, offering insights into stellar collapse, extreme matter behavior, and cosmic evolution. The advent of multi-messenger astronomy, combining electromagnetic,…
I discuss the possibility of differentiating between popular models for gamma-ray bursts by using multiwavelength observations to constrain the characteristics of their host galaxies, in particular the age of the stellar populations.
Gamma-ray bursts are still not fully understood events. However, their exploration could provide a useful tool for a better understanding of the early Universe because they belong to the most distant and violent objects that astronomers…
The immense power of gamma-ray bursts (GRBs) make them ideal probes of the early universe. By using absorption lines in the afterglows of high-redshift GRBs, astronomers can study the evolution of metals in the early universe. With an…
The discovery of a short-lived gamma-ray burst at a surprisingly early epoch in the history of the Universe shows how much is still unknown about the evolution of the parent systems of such bursts.
Evolution of the rate density of cosmological gamma-ray bursts (GRBs) is calculated and compared to the BATSE brightness distribution in the context of binary neutron-star mergers as the source of GRBs, taking account of the realistic star…
The hard X-ray (2-10keV) luminosity of a star-forming galaxy tracks its population of high mass X-ray binaries and is essentially unobscured. It is therefore a practically unbiased measure of star-formation in the host galaxies of gamma-ray…
Current observations are about to open up a direct window into the final frontier of cosmology: the first billion years in cosmic history when the first stars and galaxies formed. Even before the launch of the James Webb Space Telescope, it…