Related papers: Are gamma-ray bursts cosmological?
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 LAT instrument on the Fermi Gamma-Ray Space Telescope is performing an all-sky survey from 20 MeV to 300 GeV with unprecedented statistics and angular resolution. This is providing a wealth of new information on the non-thermal emission…
The isotropy of gamma-ray bursts collected in Current BATSE catalog is studied. It is shown that the quadrupole term being proportional to $\sim \sin 2b \sin l$ is non-zero with a probability 99.9%. The occurrence of this anisotropy term is…
There are observational facts and theoretical arguments for an origin of gamma-ray bursts in molecular clouds in distant galaxies. If this is true, one could detect a significant flux of GRB prompt and early afterglow X-ray radiation…
From the analysis of AGASA data above $4 \times 10^{19}$ eV, we show that the ultra-high energy cosmic rays flux is neither purely isotropic, nor reflects the expected anisotropy from a pure source distribution that maps large scale…
We study a cosmological scenario for gamma ray bursts (GRBs) where relativistic flows interact with dense radiation fields. It is shown that this scenario is plausible in very dense stellar regions which are known to exist in collapsed…
Our correlation analysis of Swift gamma-ray burst coordinates and nearby star locations (catalog Gliese) reveals 4 coincidences with angular accuracy better than 0.1 degree. The random probability is 2\times 10^{-4}, so evidencing that…
We consider the propagation of galactic cosmic rays under assumption that the interstellar medium is a fractal one. An anomalous diffusion equation in terms of fractional derivatives is used to describe of cosmic ray propagation. The…
The present common view about GRB origin is related to cosmology. There are two evidences in favour of this interpretation. The first is connected with statistics, the second is based on measurements of the redshifts in the GRB optical…
Cosmic-ray interactions with interstellar gas and photons produce diffuse gamma-ray emission. In this talk we will review the current understanding of this diffuse emission and its relationship to the problem of the origin of cosmic rays.…
This paper analyzes astrophysical scenarios that may be detected at the upper end of the energy range of the Gamma Ray Large Area Space Telescope (GLAST), as a result of cosmic-ray (CR) diffusion in the interstellar medium (ISM). Hadronic…
Gamma-ray bursts (GRBs) by virtue of their high luminosities can be detected up to very high redshifts and therefore can be excellent probes of the early universe. This task is hampered by the fact that most of their characteristics have a…
The distribution of the apparent total energy emitted by a gamma-ray burst reflects not only the distribution of the energy actually released by the burst engine, but also the distribution of beaming angles. Using the observed energy…
In this work, our focus is on exploring the potential of current GRB measurements to provide reliable constraints on cosmological model parameters at high redshift. This work is divided into two parts. First, we calibrate the Amati relation…
Two models of the gamma ray burst population, one with a standard candle luminosity and one with a power law luminosity distribution, are chi^2-fitted to the union of two data sets: the differential number versus peak flux distribution of…
[Abridged] Very recently, relations between the peak energy of Gamma-Ray Burst burst spectra, the isotropic-equivalent energy of the burst, and the radiated energy of the burst have been found. In a way that is exactly analogous to the way…
The estimation of light velocity dispertion caused by quantum fluctuations influence on electromagnetic wave propogation in four-dimensional space-time is presented. Analytical cosmological solutions for the flat and open Universe for the…
The gamma-ray bursts detected by the BATSE instrument may be separated into "short", "intermediate" and "long" subgroups. Previous statistical tests found an anisotropic sky-distribution on large angular scales for the intermediate…
The evidence for spectral features in gamma-ray bursts is summarized. As a guide for evaluating the evidence, the properties of gamma-ray detectors and the methods of analyzing gamma-ray spectra are reviewed. In the 1980's, observations…
We observe strong correlations between the temporal properties of gamma ray bursts (GRBs) and their apparent peak brightness. The strongest effect (with a significance level of 10^{-6}) is the difference between the brightness distributions…