相关论文: Very Energetic Gamma-Rays from Microquasars and Bi…
We will discuss the main relevant aspects of the physics of ultra high energy cosmic rays. After a short recap of the experimental evidences, we will review theoretical models aiming at describing the sources of these extremely energetic…
Active galaxies and gamma ray bursts are the sources of the highest energy photons detected by astronomical telescopes. We speculate that they may be the sources of the highest energy cosmic rays. This makes them true proton accelerators,…
Very high energy {\gamma}-rays are one of the most important messengers of the non-thermal Universe. The major motivation of very high energy {\gamma}-ray astronomy is to find sources of high energy cosmic rays. Several astrophysical…
Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars,…
Cosmic rays reaching the atmosphere of an astrophysical object produce showers of secondary particles that may then escape into space. Here we obtain the flux of gamma rays and neutrinos of energy $E>10$ GeV emitted by the Sun, Jupiter and…
The origin of the highest energy cosmic rays is still unknown. The discovery of their sources will reveal the workings of the most energetic astrophysical accelerators in the universe. Current observations show a spectrum consistent with an…
Several binary systems have been detected at High Energy (HE, E > 100 MeV) and/or Very High Energy (VHE, E > 100 GeV) gamma rays. Some of them are X-ray binaries in which accretion feeds relativistic radio jets and powers the non-thermal…
Gamma-ray blazars are among the most extreme astrophysical sources, harboring phenomena far more energetic than those attainable by terrestrial accelerators. These galaxies are understood to be active galactic nuclei that are powered by…
High-energy photons are a powerful probe for astrophysics and for fundamental physics under extreme conditions. During the recent years, our knowledge of the most violent phenomena in the Universe has impressively progressed thanks to the…
Microquasars are sources of very high-energy gamma-rays and, very probably, high-energy gamma-ray emitters. We propose a model for a jet that can allow to give accurate observational predictions for jet emission at different energies and…
I review here some of the main observational features in microquasars and AGNs as sources of high-energy gamma-rays as well as some of the current models that try to explain the emission in the gamma-ray domain.
We briefly review the main channels of gamma ray and neutrino production due to the propagation of ultra high energy cosmic rays. We show how the observations of these secondary radiations are of paramount importance in tagging mass…
Recent measurements of the properties of cosmic rays above 10^17 eV are summarized and implications on our contemporary understanding of their origin are discussed. Cosmic rays with energies exceeding 10^20 eV have been measured, they are…
Highly relativistic jets from merger and accretion induced collapse of compact stellar objects, which may produce the cosmological gamma ray bursts (GRBs), are also very efficient and powerful cosmic ray accelerators. The expected…
High-energy cosmic ray events present important challenges to particle astrophysics. Their nature and origin are often not well understood and, as they occur in an energy domain not accessible to particle accelerators, there is no clear…
High energy gamma-rays and neutrinos can be produced both by the annihilation and by the possible slow decay of dark matter particles. We discuss the fluxes and spectra of such secondaries produced by dark matter particles in the universe…
Recent results, the present status and the perspectives of high energy gamma-ray astronomy are described. Since the satellite observations by the Compton Gamma Ray Observatory and its precursor missions have been reviewed extensively,…
The field of high energy particle astronomy is exciting and rapidly developing. In the last few years, we have detected extragalactic sources of intense TeV gamma radiation and individual cosmic ray particles with energies exceeding 25…
Several issues related to the lensing of ultra-high energy cosmic rays by the Galactic magnetic field are discussed.
Various aspects of the high-energy emission from relativistic jets associated wi th compact astrophysical systems are reviewed. The main leptonic and hadronic processes responsible for the production of high-energy $\gamma$-rays, very-high…