Related papers: Some possible interpretations from data of the COD…
In 1965 it was discovered that cosmic ray air showers emit impulsive radio signals at frequencies below 100 MHz. After a period of intense research in the 1960s and 1970s, however, interest in the detection technique faded almost…
LHAASO is expected to be the most sensitive project to face the open problems in Galactic cosmic ray physics through a combined study of photon- and charged particle-induced extensive air showers in the energy range 10$^{11}$ - 10$^{17}$…
One of the most striking astrophysical phenomena today is the existence of cosmic ray particles with energies in excess of 10^20 eV. While their presence has been confirmed by a number of experiments, it is not clear where and how these…
We briefly review the status of cosmic ray studies between $10^{14}$ eV and the highest observed energies, namely a few times $10^{20}$ eV. Because of the rather low incident fluxes in this energy range, the studies mostly rely on ground…
The detection of cosmic rays with energy around and in excess of $10^{20}$ eV raises many questions that future experiments will help answering to. I address here my view of some of these open issues, as they are now and as they might be…
I review here some of the physics we are learning and expect to learn in the near future through the observation of cosmic rays. The study of cosmic rays involves a combination of data from accelerators, ground arrays, atmospheric…
Radio detection of air showers in the current era has progressed immensely to effectively extract the properties of these air showers. Primary cosmic rays with energies of hundreds of PeV have been successfully measured with the method of…
The southern Auger Observatory provides an excellent test bed to study the radio detection of extensive air showers as an alternative, cost-effective, and accurate tool for cosmic-ray physics. The data from the radio setup can be correlated…
High-energy phenomena in the cosmos, and in particular processes leading to the emission of gamma- rays in the energy range 10 MeV - 100 GeV, play a very special role in the understanding of our Universe. This energy range is indeed…
The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at southern two stations of TA are newly constructed and have now completed seven…
We present first measurements by MAYBE of microwave emission from an electron beam induced air plasma, performed at the electron Van de Graaff facility of the Argonne National Laboratory. Coherent radio Cherenkov, a major background in a…
The properties of galactic cosmic rays are investigated with the KASCADE-Grande experiment in the energy range between $10^{14}$ and $10^{18}$ eV. Recent results are discussed. They concern mainly the all-particle energy spectrum and the…
The Pierre Auger Cosmic-Ray Observatory uses the earth's atmosphere as a calorimeter to measure extensive air-showers created by particles of astrophysical origin. Some of these particles carry joules of energy. At these extreme energies,…
We report on an observation of the difference between northern and southern skies of the ultrahigh energy cosmic ray energy spectrum with a significance of ${\sim}8\sigma$. We use measurements from the two largest…
Over the last third of the century, a few tens of events, detected by ground-based cosmic ray detectors, have opened a new window in the field of high-energy astrophysics. These events have macroscopic energies, unobserved sources, an…
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…
Next-generation radio experiments such as the Radio Detector of the upgraded Pierre Auger Observatory and the planned GRAND and BEACON arrays target the detection of ultra-high-energy particle air showers arriving at low elevation angles.…
For our understanding of the origin of ultra high energy cosmic rays, the energy region between 10^17 and 10^19 eV is of crucial importance. Previous experiments have found indirect evidence that at these energies, the origin of cosmic rays…
We present a measurement of the cosmic-ray spectrum above 100\,PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750~m. An inflection of the spectrum is observed, confirming the presence of the…
Space-based astronomy of hard X-rays and gamma rays covers more than seven orders of magnitude in photon energy, from 10 keV to several hundred GeV. Detecting cosmic photons in this energy range is a challenge, due to the relatively low…