Related papers: Testing the correlations between ultra-high-energy…
We study the correlation between compact radio quasars or 3EG gamma-ray blazars and the arrival directions of cosmic rays above 10^19 eV using an updated list of air shower detections. Our Monte Carlo simulations reveal no significant…
We generalize the Maximum Likelihood-type method used to study cross correlations between a catalog of candidate astrophysical sources and Ultrahigh Energy Cosmic Rays (UHECRs), to allow for differing source luminosities. The new method is…
In a series of papers we have found statistically significant correlations between arrival directions of ultra-high energy cosmic rays and BL Lacertae objects. Recently, our calculations were partly repeated by Evans, Ferrer and Sarkar with…
We reiterate that there is no evidence that BL Lacs are sources of ultrahigh energy cosmic rays.
We review the basic ideas on the origin of cosmic rays with energy in excess of $\sim 10^{19}$ eV, in the light of the most recent observational findings. The limited statistics of events detected by the two largest experiments currently…
Observations of cosmic rays have been improving at all energies, with higher statistics and reduced systematics. Fundamental questions remain regarding the origins of cosmic rays both within the Galaxy and in extragalactic sources, and new…
For several decades, the origin of ultra-high-energy cosmic rays (UHECRs) has been an unsolved question of high-energy astrophysics. One approach for solving this puzzle is to correlate UHECRs with high-energy neutrinos, since neutrinos are…
Cosmic-rays with energies exceeding 10^{19} eV are referred to as Ultra High Energy Cosmic Rays (UHECRs). The sources of these particles and their acceleration mechanism are unknown, and for many years have been the issue of much debate.…
The HiRes Collaboration has recently announced preliminary measurements of the energy spectrum of ultra-high energy cosmic rays (UHECR), as seen in monocular analyses from each of the two HiRes sites. This spectrum is consistent with the…
The origin of ultra-high energy cosmic rays (UHECRs) is one of the enduring mysteries of high-energy astrophysics. To investigate this, we cross-correlate the recently released Fermi Large Area Telescope First Source Catalog (1FGL) with the…
The origin of cosmic rays is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely associated with the most energetic processes…
We will review the main physical aspects of Ultra High Energy Cosmic Rays. We will discuss in particular their propagation through astrophysical backgrounds, focusing on the latest experimental observations of HiRes, Telescope Array and…
We investigate whether ultra--high energy cosmic rays (UHECR) may be preferentially produced in massive galaxy clusters, by looking for correlations between UHECR directions and those of x-ray clusters. We find an excess-above-random of…
The energy density of the Ultra High Energy Cosmic Rays (UHECR) in the Universe is a very important parameter for the solution of the puzzle of their origin. It defines the luminosity of the UHECR sources and thus the type of objects they…
Spectra at the Earth of ultra-high energy cosmic rays (UHECR) from Seyfert nuclei with red shifts z<=0.0092 and from Blue Lacertae objects (BL Lac's) are calculated. The spectra are compared with the experimental data. It is shown that in…
Here we discuss the latest developments in the debate, where the ultrahigh energy cosmic ray particles come from. In this brief review, we emphasize the predictions that necessarily follow from the various concepts proposed. We discuss both…
We investigate the origin of a nearly pointlike cluster of 5 ultrahigh energy cosmic rays at RA ~169.2deg and dec ~56.8deg, using Sloan Digital Sky Survey and other data. No particular source candidates are found near the estimated source…
Some studies suggested that a correlation between locations of BL Lacertae objects (BL Lacs) and the arrival directions of the ultrahigh energy cosmic rays (UHECRs) exists. Especially by assuming the primary particles charged +1 and using a…
The two-point autocorrelation function of ultra-high energy cosmic ray (UHECR) arrival directions has a broad maximum around 25 degrees, combining the data with energies above $4\times 10^{19}$ eV (in the HiRes energy scale) of the HiRes…
We investigate the possibility that ultra high energy cosmic rays (E > 10^19 eV) are related to the distribution of matter on large scales. The large scale structure (LSS) data stems from the recent IRAS PSCz redshift survey. We present…