Related papers: The most energetic cosmic rays and their possible …
Several gamma-ray observatories have discovered photons of cosmic origin with energies in the PeV ($10^{15}\,\text{eV}$) range. Photons at these energies might be produced as by-products from particle acceleration in so-called PeVatrons,…
The latest observations of extensive air showers (EAS) induced by ultra-high-energy cosmic rays (UHECR) appear to indicate, prima facie, a transition to heavy primaries at the highest energies. However, this interpretation, which is based…
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.…
High-energy cosmic ray air-showers have been known for over 30 years to emit strong radio pulses in the regime between a few and several 100 MHz (Allan 1971). To date, however, a thorough analysis of the emission mechanisms has not yet been…
Three regions of excessive flux of cosmic rays with energies of the order of PeV are found in the experimental data of the EAS MSU array at a confidence level greater than 4\sigma. For two of them, there are similar regions in the…
The energy spectrum of cosmic rays above 2.5x10^18eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the flux, J ~ E^-gamma, at energies between 4x10^18eV and 4x10^19eV is…
The lateral distribution of particles in extensive air showers from cosmic rays with energy above $10^{17}$ eV registered at the Yakutsk complex array was analyzed. Experimentally measured particle densities were compared to the predictions…
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,…
Laboratory experiments to explore plasma conditions and stimulated particle acceleration can illuminate aspects of the cosmic particle acceleration process. Here we discuss the cosmic-ray candidate source object variety, and what has been…
Measurements of air showers are accumulating at an increasing rate while construction proceeds at the Pierre Auger Observatory. Although the southern site is only half complete, the cumulative exposure is already similar to those achieved…
In this report we review the important progress made in recent years towards understanding the experimental data on ultra-high-energy ($E \gtrsim 10^9$ GeV) cosmic rays. We begin with a general survey of the available data, including a…
While there is some level of consensus on a Galactic origin of cosmic rays up to the knee ($E_{k}\sim 3\times 10^{15}$ eV) and on an extragalactic origin of cosmic rays with energy above $\sim 10^{19}$ eV, the debate on the genesis of…
This review summarizes recent developments in the understanding of high-energy cosmic rays. It focuses on galactic and presumably extragalactic particles in the energy range from the knee (10^15 eV) up to the highest energies observed…
We present the main results on the energy spectrum and composition of the highest energy cosmic rays of energy exceeding 10$^{18}$ eV obtained by the High Resolution Fly's Eye and the Southern Auger Observatory. The current results are…
The observation of twenty cosmic-ray air-showers at and above 10^{20} eV poses fascinating problems for particle astrophysics: how the primary particles are accelerated to these energies, how the primaries get here through the 2.7K…
The two most powerful extensive air showers (EAS) with energies of about $10^{20}$ eV, registered at the Yakutsk EAS array during the entire observation period of 1974-2024, are considered. Both showers hit the array near the center and…
Cosmic rays are a sample of solar, galactic and extragalactic matter. Their origin and properties are one of the most intriguing question in modern astrophysics. The most energetic events and active objects in the Universe: supernovae…
The cosmic ray spectrum at $10^{19}{\rm eV}-10^{20}{\rm eV}$, reported by the Fly's Eye and the AGASA experiments, is shown to be consistent with a cosmological distribution of sources of protons, with a power law generation spectrum ${\rm…
The paper presents short technical description of Yakutsk Radio Array and some preliminary results obtained from measurements of radio emission at 32 MHz frequency induced by air shower particles with energy…
The Telescope Array Collaboration has observed a cosmic-ray event with estimated primary energy of 1.38*10^20 eV whose arrival direction coincides (see arxiv:1205.5984), given the angular resolution of 1.5 deg, with that of an event with…