Related papers: Correlation between Compact Radio Quasars and Ultr…
We discuss the rationale for the energy cuts used in the previous study of directional correlation of the five highest energy cosmic ray events with compact, radio quasars. We check the consistency of the next three most energetic events…
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 examine the correlation between compact radio quasars (redshifts in the range $z = 0.3 - 2.2$) and the arrival direction of ultrahigh energy cosmic rays forming clusters. Our Monte Carlo simulation reveals a statistically significant…
In a recent paper, Farrar and Biermann argue that there is a strong correlation between the direction of the five highest-energy cosmic-ray events and compact, radio-loud quasars. This Comment shows that this analysis contains several…
Angular correlations of ultra-high energy cosmic rays with cosmologically distant sources may provide clues to these mysterious events. We compare cosmic ray tracks with energies above $ 10^{20}eV$ to a compilation of radio-loud compact QSO…
The clustering of ultra high energy (above 10^20 eV) cosmic rays (UHECR) suggests that they might be emitted by compact sources. Statistical analysis of Dubovsky et al. (Phys. Rev. Lett. 85 (2000) 1154) estimated the source density. We…
Five ultrahigh energy cosmic rays in the combined AGASA and HiRes stereo data are analyzed to test whether they come from a single source. The quad above 37 EeV in the 94-event high energy dataset can be analyzed without considering…
The connection between the arrival directions of ultrahigh energy cosmic rays by using the EAS array data and point galactic sources of radio-and gamma-radiations, pulsars,is sought. At the mean particle energy of 10^{19} eV the correlation…
Very recently, a possible clustering of a subset of observed ultrahigh energy cosmic rays above about 40EeV (4x10^19eV) in pairs near the supergalactic plane was reported. We show that a confirmation of this effect would provide information…
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…
Recently the Telescope Array collaboration reported an observation of cosmic ray event with very high energy 244 EeV ($2.44 \times 10^{20}$ eV). Importantly, the event is hard to correlate with the matter distribution in the local Universe,…
The clustering of ultrahigh energy (>10^{20} eV) cosmic rays (UHECR) suggests that they might be emitted by compact sources. Statistical analysis (Dubovsky et al., 2000) estimated the source density. We extend their analysis to give also…
Ultra High Energy Cosmic Rays, UHECR, are charged particles with energies between $\sim10^{18}\,{\rm eV}$ and $\sim3\times10^{20}\,{\rm eV}\sim50\,{\rm J}$. They exhibit fundamental physics at energies inaccessible to terrestrial…
The clustering properties of the highest energy cosmic rays and their correlations with candidate sources are re-examined using the most recently available AGASA data and a rigorous correlation analysis. The statistical methodology…
The present situation with regard to experimental data on ultra high-energy cosmic rays is briefly reviewed. Whilst detailed knowledge of the shape of the energy spectrum is still lacking, it is clear that events above 10^20 eV do exist.…
Anisotropy in arrival directions of ultrahigh energy cosmic rays offers the most direct way to search for the sources of these particles. We present estimates of the angular correlation in the HiRes sample of stereo events above 10 EeV, and…
A detailed investigation of radio galaxies has recently stressed these sources as the possible origin of the cosmic rays observed above $3\,\text{EeV}$. Here, the relevance of this model at energies below $3\,\text{EeV}$ is investigated.…
As recently suggested, nearby quasar remnants are plausible sites of black-hole based compact dynamos that could be capable of accelerating ultra-high energy cosmic rays (UHECRs). In such a model, UHECRs would originate at the nuclei of…
The existence of cosmic rays of energies exceeding 10^20 eV is one of the mysteries of high energy astrophysics. The spectrum and the high energy to which it extends rule out almost all suggested source models. The challenges posed by…
Observation of clustering of ultra-high energy cosmic rays (UHECR) suggests that they are emitted by compact sources. Assuming small deflection of UHECR during the propagation, the statistical analysis of clustering allows to estimate the…