Related papers: Cosmic Rays in the Galactic Center Region
The origin of Galactic cosmic rays (with energies up to 10^15 eV) remains unclear, though it is widely believed that they originate in the shock waves of expanding supernova remnants. Currently the best way to investigate their acceleration…
It is presumed that the observed cosmic rays up to about $3\times 10^{18}$ eV are of Galactic origin, the particles being the ones which are found in the composition of the stellar winds of stars that explode as supernova into the…
The conditions in the Galactic Center are often compared with those in starburst systems, which contain higher supernova rates, stronger magnetic fields, more intense radiation fields, and larger amounts of dense molecular gas than in our…
It is believed that the observed diffuse gamma ray emission from the galactic plane is the result of interactions between cosmic rays and the interstellar gas. Such emission can be amplified if cosmic rays penetrate into dense molecular…
Cosmic rays could be produced via shock acceleration powered by supernovae. The supernova hypothesis implies that each supernova injects on average some 1e50 erg in cosmic rays, while the shock acceleration model predicts a powerlaw cosmic…
The little we do know of the physical conditions in gamma-ray bursters makes them conducive to the acceleration of high-energy cosmic rays, especially if they are at cosmological distances. We find that, with the observed statistics and…
This paper deals with the cosmic-ray penetration into molecular clouds and with the related gamma--ray emission. High energy cosmic rays interact with the dense gas and produce neutral pions which in turn decay into two gamma rays. This…
The majority of galactic gamma rays are produced by interaction of cosmic rays with matter or radiation fields. This results in a diffuse radiation concentrated in the galactic plane where the flux of cosmic rays and the density of material…
Recent results from the HESS gamma ray telescope have shown the presence of both a diffuse, extended, flux of gamma rays above ~0.4 TeV and discrete sources in and near the Galactic Centre. Here, we put forward a possible explanation in…
Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in…
The Milky Way's galactic center is a highly dynamical, crowded environment. Gamma ray observations of this region, such as the excess of GeV scale gamma rays observed by Fermi LAT, have been of tremendous interest to both the high energy…
One of the most exciting discoveries of recent years is a pair of gigantic gamma-ray emission regions, the so-called Fermi bubbles, above and below the Galactic center. The bubbles, discovered by the Fermi space telescope, extend up to…
The center of the our Galaxy is a region where very energetic phenomena take place. In particular powerful cosmic ray sources can be located in that region. The cosmic rays accelerated in these sources may interact with ambient protons…
During the last decades, increasingly precise astronomical observations of the Galactic Centre (GC) region at radio, infrared, and X-ray wavelengths laid the foundations to a detailed understanding of the high energy astroparticle physics…
A gamma-ray excess over background has been claimed in the inner regions of the Galaxy, triggering some excitement about the possibility that the gamma rays originate from the annihilation of dark matter particles. We point out that the…
Cosmic rays fill up the entire volume of galaxies, providing an important source of heating and ionisation of the interstellar medium, and may play a significant role in the regulation of star formation and galactic evolution. Diffuse…
Here we propose that the excess flux of particle events of energy near 1 EeV from the direction of the Galactic Center region is due to the production of cosmic rays by the last few Gamma Ray Bursts in our Galaxy. The basic idea is that…
The Galactic centre - as the closest galactic nucleus - holds both intrinsic interest and possibly represents a useful analogue to star-burst nuclei which we can observe with orders of magnitude finer detail than these external systems. The…
We revisit the idea that the Galactic center (GC) is the dominant source of Galactic cosmic rays (GCRs), based on a series of new observational evidence. A unified model is proposed to explain the new phenomena of GCRs and $\gamma$-rays…
It is widely believed that supernova remnants are the best candidate sources for the observed cosmic ray flux up to the knee, i.e. up to ~PeV energies. Indeed, the gamma-ray spectra of some supernova remnants can be well explained by…