Related papers: Secondary Photons from High-energy Protons Acceler…
We demonstrate by numerical flux calculations that neutrino beams producing the observed highest energy cosmic rays by weak interactions with the relic neutrino background require a non-uniform distribution of sources. Such sources have to…
X-ray synchrotron emission tells us of the highest energy reached by accelerated electrons. In a few supernova remnants (SN 1006, G347.3-0.5) this is the dominant form of X-ray radiation, but in most it is superposed to the dominant thermal…
A simple model is exhibited in which the remnant density of charged vortons is used to provide candidates for explaining the observed ultra high energy cosmic rays (above $10^{20}$ eV). These vortons would be accelerated in active galaxies…
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 Fermi-LAT telescope has unexpectedly discovered GeV gamma-ray emission from the symbiotic Nova V407 Cygni. We investigate the radiation processes due to electrons and hadrons accelerated during the explosion of this Nova. We consider a…
Molecular clouds are expected to emit non-thermal radiation due to cosmic ray interactions in the dense magnetized gas. Such emission is amplified if a cloud is located close to an accelerator of cosmic rays and if energetic particles can…
There are several types of Galactic sources that can potentially accelerate charged particles up to GeV and TeV energies. We present here the results of our observations of the source class of gamma-ray binaries and the subclass of binary…
Proton acceleration in nearby blazars can be diagnosed measuring their intense TeV $\gamma$-ray emission. Flux predictions for 1101+384 (Mrk421) and 1219+285 (ON231), both strong EGRET sources (0.1-10 GeV), are obtained from model spectra…
Supernova remnants are known to accelerate cosmic-rays from the detection of non-thermal emission in radio waves, X-rays, and gamma-rays. However, the ability to accelerate cosmic-rays up to PeV energies has yet to be demonstrated. The…
We show that it appears possible for starburst galaxies, like the nearby NGC 253, recently identified as a TeV source by the CANGAROO collaboration, to emit a significant amount of high-energy gamma-rays and neutrinos through hadronic…
We discuss the production of ultra high energy secondary protons by cosmic ray primary nuclei propagating in the intergalactic space through Cosmic Microwave Background (CMB) and Infrared (IR) radiations. Under the assumption that only…
Massive protostars have associated bipolar outflows with velocities of hundreds of km s$^{-1}$. Such outflows can produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. We aim at…
We discuss the GeV to TeV photon emission of gamma-ray bursts (GRBs) within the refreshed shock and the continuous injection scenarios, motivated by the observation of extended emission in a substantial fraction of short GRBs. In the first…
It has been suggested that some classes of luminous supernovae (SNe) and gamma-ray bursts (GRBs) are driven by newborn magnetars. Fast-rotating proto-neutron stars have also been of interest as potential sources of gravitational waves…
Suppose that even the highest energy cosmic rays (CRs) observed on Earth are protons accelerated in local Milky Way Galaxy sources, with few if any from more distant sources. In this paper we treat the problem that supernovae remnants…
The production of high-energy astrophysical neutrinos is tightly linked to the emission of hadronic gamma-rays. I will discuss the recent observation of TeV to PeV neutrinos by the IceCube Cherenkov telescope in the context of gamma-ray…
Shock breakout X-ray emission has been reported for the first time from a supernova connected with a gamma-ray burst, namely GRB060218/SN2006aj. The gamma-ray emission and the power-law decaying X-ray afterglow are ascribed to a highly…
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…
We report recent results of the CANGAROO Collaboration on very high energy gamma ray emission from pulsars, their nebulae, SNR and AGN in the southern sky. Observations are made in South Australia using the imaging technique of detecting…
We estimate the TeV gamma-ray fluxes expected from the population of young pulsars in terms of the self-consistent time dependent hadronic-leptonic model for the high energy processes inside the pulsar wind nebulae. This radiation model…