Related papers: Cosmic rays of leptons from Pulsars and Supernova …
Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been…
The positron fraction in cosmic rays was found to be a steadily increasing in function of energy, above $\sim$ 10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the…
The lineless power-law emission observed by ASCA from the northeastern rim of the supernova remnant SN1006 has recently been interpreted as synchrotron radiation of electrons with energies around 100 TeV. In this letter we calculate the…
The excess of cosmic-ray electron and positron fluxes measured by the PAMELA satellite and ATIC balloon experiments may be interpreted as the signals of the dark matter annihilation or decay into leptons. In this letter we show that the…
The last decade has been dense with new developments in the search for the sources of Galactic cosmic rays. Some of these developments have confirmed the tight connection between cosmic rays and supernovae in our Galaxy, through the…
Recent precision measurements of the flux of cosmic ray positrons by the Alpha Magnetic Spectrometer show that the spectrum has a marked softening feature for energies close to one TeV. A possible interpretation of this result is that the…
I review latest results from AMS on electrons and positrons in primary cosmic rays in the GeV to TeV energy range. Separate fluxes for electrons and positrons as well as their sum are presented. Neither of the fluxes is compatible with a…
We study the production of cosmogenic neutrinos and photons during the extragalactic propagation of ultra-high-energy cosmic rays (UHECRs). For a wide range of models in cosmological evolution of source luminosity, composition and maximum…
In cosmic ray physics extensive progress has been made in recent years, both concerning theory and observation. The vast details in direct, indirect and secondary detections on the one hand provide the basis for a detailed modeling of the…
The cosmic-ray positron flux calculated using the cosmic-ray nuclei interactions in our Galaxy cannot explain observed data above 10 GeV. An excess in the measured positron flux is therefore open to interpretation. Nearby pulsars, located…
One century ago Viktor Hess carried out several balloon flights that led him to conclude that the penetrating radiation responsible for the discharge of electroscopes was of extraterrestrial origin. One century from the discovery of this…
PAMELA's observation that the cosmic ray positron fraction increases rapidly with energy implies the presence of primary sources of energetic electron-positron pairs. Of particular interest is the possibility that dark matter annihilations…
The development of techniques whereby gamma rays of energy 100 GeV and above can be studied from the ground, using indirect, but sensitive, techniques has opened up a new area of high energy photon astronomy. The most exciting result that…
Recent results of GeV and TeV observations of gamma-rays from the Universe are briefly reviewed. Topics include observational technique, diffuse gamma-rays, pulsars, unidentified sources, plerions, supernova remnants and AGNs.
The origin of galactic cosmic rays is one of the most interesting unsolved problems in astroparticle physics. Experimentally, the problem is attacked by a multi-disciplinary effort, namely by direct measurements of cosmic rays above the…
If supernova remnants (SNRs) are the sites of cosmic-ray acceleration, the associated nuclear interactions should result in observable fluxes of TeV gamma-rays from the nearest SNRs. Measurements of the gamma-ray flux from six nearby,…
We present a novel calculation of the spectrum of electrons and positrons from random sources, supernova remnants and pulsars, distributed within the spiral arms of the Galaxy. The pulsar emissivity in terms of electron-positron pairs is…
The supernova explosion which deposited $^{60}$Fe isotopes on Earth 2-3 million years ago should have also produced cosmic rays which contribute to the locally observed cosmic ray flux. We show that the contribution of this "local source"…
We study the origin of the positron excess observed in the local cosmic-ray spectrum at high energies, and relate it to the cosmic rays and gamma-ray emission across the entire Galaxy. In particular, we explore the hypothesis of a single,…
High energy neutrinos with energy typically greater than tens of thousands of GeV may originate from several astrophysical sources. The sources may include, for instance, our galaxy, the active centers of nearby galaxies, as well as…