Related papers: On the Temporal Variability of the Galactic Multi-…
Supernova remnants (SNRs) are widely believed to be the principal source of galactic cosmic rays. Such energetic particles can produce gamma-rays and lower energy photons via interactions with the ambient plasma. In this paper, we present…
In light of the latest IceCube data, we discuss the implications of the cosmic ray energy input from hypernovae and supernovae into the Universe, and their propagation in the hosting galaxy and galaxy clusters or groups. The magnetic…
Cosmic rays (CRs) leave their sources mainly along the local magnetic field; in doing so they excite both resonant and nonresonant modes through streaming instabilities. The excitation of these modes leads to enhanced scattering and in turn…
The investigation of VHE gamma-ray sources by any methods, including mirror Cherenkov telescopes, touches on the problem of the cosmic ray origin and, accordingly, the role of the Galaxy in their generation. The SHALON observations have…
Many recent numerical studies have argued that cosmic rays (CRs) from supernovae (SNe) or active galactic nuclei (AGN) could play a crucial role in galaxy formation, in particular by establishing a CR-pressure dominated circum-galactic…
The origin of Galactic Cosmic Rays (GCRs) and the potential role of Supernova Remnants (SNRs) as cosmic-ray (CR) accelerators remain subjects of ongoing debate. To shed more light on this topic, we have studied the spectral shape of two…
We treat of the high-energy astrophysics of the inner ~200 pc of the Galaxy. Our modelling of this region shows that the supernovae exploding here every few thousand years inject enough power to i) sustain the steady-state, in situ…
Cosmic ray (CR) feedback in galaxy evolution has seen a theoretical resurgence in the past decade, but significant uncertainties remain in CR transport through the interstellar and circum-galactic media (ISM and CGM). While several works…
The propagation of TeV-PeV cosmic rays (CR) in our Galaxy can be described as a diffusive process. We discuss here two effects, with important observational consequences, that cannot be predicted by the diffusion approximation in its usual…
Diffusive shock acceleration in supernova remnants is the most widely invoked paradigm to explain the Galactic cosmic ray spectrum. Cosmic rays escaping supernova remnants diffuse in the interstellar medium and collide with the ambient…
We have mapped 16 edge-on galaxies at 20 cm using the VLA. For 5 galaxies, we could form spectral index, energy and magnetic field maps. We find that all but one galaxy show evidence for non-thermal high latitude radio continuum emission,…
The observed flux of ultra-high energy (UHE) cosmic rays (CRs) guarantees the presence of high-energy cosmogenic neutrinos that are produced via photo-hadronic interactions of CRs propagating through intergalactic space. This flux of…
It has been shown that supernova blast waves interacting with winds from massive stars in compact star clusters may be capable of producing cosmic-ray (CR) protons to above $10^{17}$ eV. We give a brief description of the…
We provide our estimates of the intensity of the gamma-ray emission with an energy near 0.1 TeV generated in inrergalactic space in the interactions of cosmic rays with background emissions. We assume that the cosmic ray sources are…
Recent observations of the diffuse Galactic gamma-ray emission by the Fermi-LAT satellite have shown significant deviations from models which assume the same diffusion properties for cosmic rays (CR) throughout the Galaxy. We explore the…
Recent cosmic ray (CR) measurements have revealed unexpected anomalies in secondary CRs, namely deviations from the predictions of the so-called standard Galactic CR paradigm regarding the composition and energy spectra of the products of…
Gamma-ray bursts (GRBs) are proposed as candidate sources of ultra-high energy cosmic rays (UHECRs). We study the possibility that the PeV neutrinos recently observed by IceCube are produced by GRB cosmic rays interacting with the…
In this work we develop a new propagation model for the Galactic cosmic rays based on the GALPROP code, including contributions from dark matter annihilation. The model predicts compatible Galactic diffuse $\gamma$ ray spectra with EGRET…
A long BeppoSAX observation of the Galactic Center region shows that the spectrum of the diffuse X-ray emission from the SgrA Complex can be described with the sum of two thermal plasma models with temperatures of ~0.6 keV and \~8-9 keV.…
Galactic diffuse continuum gamma-ray emission is intricately related to cosmic-ray physics and radio astronomy. We describe recent results from an approach which endeavours to take advantage of this. Information from cosmic-ray composition…