相关论文: Interstellar Gamma Ray Lines from Low Energy Cosmi…
Recent international efforts have brought us closer to unveiling the century old mystery of the origin of cosmic rays. Cosmic ray, gamma ray, and neutrino observatories are reaching the necessary sensitivity to study the highest energy…
We review gamma-ray observations that constrain antimatter - both baryonic and leptonic - in the Universe. Antimatter can be probed through ordinary matter, with the resulting annihilation gamma-rays providing indirect evidence for its…
RXTE, GINGA, and OSSE observations have revealed an intense low-energy gamma-ray continuum emission from the Galactic plane, which is commonly interpreted as evidence for the possible existence of a strong flux of low-energy cosmic ray…
We discuss the relation between cosmic-ray induced interstellar gamma-ray and radio emission from our Galaxy, and emphasize the importance of their parallel study. We give an overview of results from Fermi-LAT on the interstellar gamma-ray…
The diffuse gamma-ray background radiation (GBR) at high Galactic latitudes could be dominated by inverse Compton scattering (ICS) of cosmic ray (CR) electrons on the cosmic microwave background radiation (CBR) and on starlight (SL) in an…
The bulk of the diffuse galactic gamma-ray emission above a few tens of GeV has been conventionally ascribed to the decay of neutral pions produced in cosmic-ray interactions with interstellar matter. Cosmic-ray electrons may, however, make…
A very interesting puzzle about the origin of electron and positron cosmic rays is deduced from the latests experimental results. We model the propagation of such cosmic rays in terms of a successfully tested two--zone propagation model.…
Recent gamma-ray observations have detected photons up to energies of a few PeV. These highly energetic gamma rays are emitted by the most powerful sources in the Galaxy. Propagating over astrophysical distances, gamma rays might interact…
It is suggested that the decline with energy of the boron to carbon abundance ratio in Galactic cosmic rays is due, in part, to a correlation between the maximum energy attainable by shock acceleration in a given region of the Galactic disk…
We compute the attenuation of gamma-rays from remote quasars due to interactions with ambient low-energy photons produced by stars in galaxies and show that the next-generation gamma ray telescopes can probe the cosmic star formation rate…
Structure formation in the intergalactic medium (IGM) produces large-scale, collisionless shock waves, where electrons can accelerate to highly relativistic energies. Such electrons can Compton scatter cosmic microwave background photons up…
Low-energy cosmic rays (LECRs) play a crucial role in the formation of planetary systems, and detecting and reconstructing the properties of early LECRs is essential for understanding the mechanisms of planetary system formation. Given that…
Context. Near a dozen star-forming galaxies have been detected in gamma-rays by the Fermi observatory in the last decade. A remarkable property of this sample is the quasi-linear relation between the gamma-ray luminosity and the star…
The electron and positron cosmic rays observations have impulsed a hot debate regarding the origin of such particles. Their propagation in the galactic medium is modeled according to a successfully tested two--zone propagation model. The…
The origin of the extragalactic gamma-ray background is a pressing cosmological mystery. The Fermi Gamma-Ray Space Telescope has recently measured the intensity and spectrum of this background; both are substantially different from previous…
Gamma-ray emission produced by interactions between cosmic rays (CRs) and interstellar gas traces the product of their densities throughout the Milky Way. The outer Galaxy is a privileged target of investigation to separate interstellar…
The origin of cosmic rays is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely associated with the most energetic processes…
Latest precise cosmic-ray (CR) measurements and present gamma-ray observations have started challenging our understanding of CR transport and interaction in the Galaxy. Moreover, because the density of CRs is similar to the density of the…
Motivated by the PAMELA anomaly in the fluxes of cosmic-ray positron and electron, we study the cosmic gamma-ray induced by the inverse Compton (IC) scattering process in unstable dark matter scenario assuming that the anomaly is due to the…
We show that cosmic rays in external galaxies, groups and clusters rich in gas, with an average flux similar to that observed in the Milky Way, could have produced the observed extragalactic diffuse gamma radiation.