Related papers: The Galactic Diffuse Gamma-ray Spectrum from Cosmi…
Recent direct measurements of Galactic cosmic ray spectra by balloon/space-borne detectors reveal spectral hardenings of all major nucleus species at rigidities of a few hundred GV. The all-sky diffuse gamma-ray emissions measured by the…
The Fermi-LAT collaboration recently confirmed EGRET finding of a discrepancy between the observed longitudinal profile of gamma-ray diffuse emission from the Galaxy and that computed with GALPROP assuming that cosmic rays are produced by…
"Diffuse" gamma rays consist of several components: truly diffuse emission from the interstellar medium, the extragalactic background, whose origin is not firmly established yet, and the contribution from unresolved and faint Galactic point…
Recently, Dixon et al. have re-analyzed the EGRET data, finding a statistically significant diffuse $\gamma$-ray emission from the galactic halo. We show that this emission can naturally be explained within a previously-proposed model for…
Cosmic-ray (CR) protons can accumulate for cosmological times in clusters of galaxies. Their hadronic interactions with protons of the intra-cluster medium (ICM) generate secondary electrons, gamma-rays and high-energy neutrinos. In light…
Very-high-energy gamma rays produce electron positron pairs in interactions with low-energy photons of extragalactic background light during propagation through the intergalactic medium. The electron-positron pairs generate secondary gamma…
In this work, we propose a novel mechanism for generating gamma rays from the Galactic Center via scattering of cosmic-ray protons off dark matter in the Milky Way halo, in contrast to conventional explanations based on dark matter…
Multiwavelength observations suggest that clusters are reservoirs of vast amounts relativistic electrons and positrons that are either injected into and accelerated directly in the intra-cluster medium, or produced as secondary pairs by…
We calculate the flux of radio, hard X-ray and UV radiation from clusters of galaxies as produced by synchrotron emission and Inverse Compton Scattering of electrons generated as secondaries in cosmic ray interactions in the intracluster…
Measurements of cosmic-ray (CR) positron fraction by PAMELA and other experiments have found an excess above 10 GeV relative to the standard predictions for secondary production in the interstellar medium (ISM). Although the excess has been…
We perform the first direct consistency check between the recently measured proton spectrum at the knee by Large High Altitude Air Shower Observatory (LHAASO) and the collaboration's own high-precision mapping of Galactic diffuse gamma-ray…
The diffuse Galactic $\gamma$-rays from EGRET observation shows excesses above 1 GeV in comparison with the expectations from conventional Galactic cosmic ray (CR) propagation model. In the work we try to solve the "GeV excess" problem by…
Active galactic nuclei (AGN) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary gamma rays produced along the line of sight by the interactions of…
Diffuse emission in gamma-rays and neutrinos are produced by the interaction of cosmic rays with the interstellar medium. Below some hundreds of TeV, the sources of these cosmic rays are most likely Galactic. Hence, observations of…
Conventional indirect dark matter (DM) searches look for an excess in the electromagnetic emission from the sky that cannot be attributed to known astrophysical sources. Here, we argue that the photon polarisation is an important feature to…
Using an effective interaction approach to describe the interactions between the dark matter particle and the light degrees of freedom of the standard model, we calculate the gamma-ray flux due to the annihilation of the dark matter into…
We present the angular distribution of gamma rays produced by proton-proton interactions in parameterized formulae to facilitate calculations in astrophysical environments. The parameterization is derived from Monte Carlo simulations of the…
Recent data from ATIC, CREAM and PAMELA indicate that the cosmic ray energy spectra of protons and nuclei exhibit a remarkable hardening at energies above 100 GeV per nucleon. We propose that the hardening is an interstellar propagation…
The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. This excess shows all the features expected from Dark Matter WIMP Annihilation:…
We make a new estimate of the extragalactic radio background down to kHz frequencies based on the observed luminosity functions and radio spectra of normal galaxies and radio galaxies. We have constructed models for the spectra of these two…