Related papers: KASCADE-Grande Limits on the Isotropic Diffuse Gam…
A particle cascade (shower) in a dielectric, for example as initiated by an ultra-high energy cosmic ray, will have an excess of electrons which will emit coherent \v{C}erenkov radiation, known as the Askaryan effect. In this work we study…
The Large High-Altitude Air Shower Observatory (LHAASO) recently published measurements of diffuse Galactic gamma-ray emission (DGE) in the 10-1000 TeV energy range. The measured DGE flux is significantly higher than the expectation from…
Recent results from the KASCADE experiment on measurements of cosmic rays in the energy range of the knee are presented. Emphasis is placed on energy spectra of individual mass groups as obtained from an two-dimensional unfolding applied to…
Utilizing the Fermi measurement of the gamma-ray spectrum toward the Galactic Center, we derive some of the strongest constraints to date on the dark matter (DM) lifetime in the mass range from hundreds of MeV to above an EeV. Our…
The measurement of the anisotropy in the arrival direction of cosmic rays is complementary to the study of their energy spectrum and chemical composition to understand their origin and propagation. It is also a tool to probe the structure…
In 1998 and 1999 the Whipple Observatory 10 m telescope was used to search for diffuse gamma ray emission from the Galactic Plane. No signifiant evidence of emission was found. Assuming the TeV emission profile matches EGRET observations…
The high school project on astrophysics research with cosmics (HiSPARC) employs a large number of small detection stations that sample the footprint of extensive cosmic ray air showers. The majority of these stations has two 0.5…
The energies of cosmic rays, fully ionized charged nuclei, extend over a wide range up to 10^20 eV. A particularly interesting energy region spans from 10^14 to 10^18 eV, where the all-particle energy spectrum exhibits two interesting…
Observations of the globular cluster 47 Tucanae (NGC 104), which contains at least 23 millisecond pulsars, were performed with the H.E.S.S. telescope system. The observations lead to an upper limit of F(E>800 GeV) < 6.7e-13 / cm^2 s on the…
The energy spectrum of cosmic rays in the range 10^15 eV to 6*10^19 eV has been studied using the air Cherenkov light detectors of the Yakutsk array. The total flux of photons produced by relativistic electrons (including positrons as well,…
During the last decade ground-based very high-energy gamma-ray astronomy achieved a remarkable advancement in the development of the observational technique for the registration and study of gamma-ray emission above 100 GeV. It is widely…
Although cosmic rays were discovered 90 years ago, we do not know how and where they are accelerated. There is compelling evidence that the highest energy cosmic rays are extra-galactic -- they cannot be contained by our galaxy's magnetic…
Following a recent detection of TeV radiation by the Large High Altitude Air Shower Observatory (LHAASO) and the High-Altitude Water Cherenkov Observatory (HAWC), coincident with the direction of the microquasar V4641 Sgr, we search for…
The paper describes methods used for the detection of cosmic rays with energies above 10^18 eV (UHECR, UltraHigh Energy Cosmic Rays). It had been anticipated there would be a cutoff in the energy spectrum of primary cosmic rays around 3…
A new method to derive an upper limit on photon primaries from small data sets of air showers is developed which accounts for shower properties varying with the primary energy and arrival direction. Applying this method to the…
On December 27th 2004, a giant gamma flare from the Soft Gamma-ray Repeater 1806-20 saturated many satellite gamma-ray detectors. This event was by more than two orders of magnitude the brightest cosmic transient ever observed. If the gamma…
Measurements of cosmic ray fluxes by the PAMELA and CREAM experiments show unexpected spectral features between 200 GeV and 100 TeV. They could be due to the presence of nearby and young cosmic ray sources. This can be studied in the myriad…
Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of ~ 10^15 eV. We report the detection of gamma rays -- tracers…
Purposeful investigation of radiation fluxes strongly delayed in relation to the main particles front of extensive air shower (EAS) was undertaken at the Tien Shan Mountain Cosmic Ray Station. It was found that the passage of the EAS can be…
Gamma ray source detection above 30TeV is an encouraging approach for finding galactic cosmic ray origins. All sky survey for gamma ray sources using wide field of view detector is essential for population accumulation for various types of…