Cosmic rays: air showers from low to high energies

The Physics of UHECRs: Spectra, Composition and the Transition Galactic-Extragalactic

“…The propagation of UHECR through the intergalactic medium is conditioned primarily by astrophysical photon backgrounds and, if any, by the presence of [17]. All these experiments confirm the dip behavior with good accuracy, including also the data of Fly's Eye [17] (not presented here).…”

“…[Right panel] Energy spectra of UHECR as released in 2015 by Auger (red points) and TA (blu points). Also labelled, in both datasets, are: the energy of the ankle E ankle , the energy of the high energy suppression E 1/2 and the systematics in energy determination (figure taken from [17]). …”

“…In figure 1 (right panel) we plot this comparison as presented at the last International Cosmic Rays Conference [17], also labelled are the position of the ankle and the high energy suppression as measured in the two datasets. Apart from a shift in the energy determination, which can be reabsorbed in systematics uncertainties as labelled in right panel of figure 1, it follows that the two datasets seem discrepant at the highest energies in both shape and position of the suppression.…”

Progress in high-energy cosmic ray physics

“…We also consider the cosmic ray anisotropies, both at large and small angular scales, presenting the results obtained from the TeV up to the highest energies and discuss the models proposed to explain their origin.These showers include a hadronic component consisting of protons, neutrons, pions, kaons and heavier mesons and baryons, an electromagnetic component consisting of electrons, positrons and photons as well as a muonic component and neutrinos. Hence, detectors at high elevation mountains, such as those in the Tibet YBJ laboratory, are used to study CRs with TeV-PeV energies, while lower elevations are preferred for the study of the more penetrating showers from CRs with higher energies (see [2] for a recent overview and references).Besides the sampling of the particles at ground level with arrays of detectors, also the light emitted by the passage through the atmosphere of the electrons and positrons in the shower can be detected using telescopes on the ground. This light is produced as forward Cherenkov radiation when these particles travel faster than the speed of light in air or as isotropic fluorescence due to the emission from molecular nitrogen that got excited by the passage of the charged particles.…”

Interpreting correlated observations of cosmic rays and gamma-rays from Centaurus A with a proton blazar inspired model

“…In the present work, we have used the PAO measured data on the differential energy spectrum of cosmic-rays which is available on their website (also given in [62]) and we have exploited the energy-dependent average logarithmic mass of observed cosmic rays as extracted by PAO considering EPOS…”