相关论文: Annihilation Radiation in the Galaxy
The astronomical dark matter could be made of weakly interacting massive species whose mutual annihilations should produce antimatter particles and distortions in the corresponding energy spectra. The propagation of cosmic rays inside the…
In this study, a fully self-consistent method was developed to obtain the wave functions of the positron and electrons in molecules simultaneously. The wave function of a positron at room temperature , with a characteristic energy of…
We analyze the first two years of data from the Fermi Gamma Ray Space Telescope from the direction of the inner 10 degrees around the Galactic Center with the intention of constraining, or finding evidence of, annihilating dark matter. We…
We describe the anisotropy of dark matter clump distribution caused by tidal destruction of clumps in the Galactic disk. A tidal destruction of clumps with orbit planes near the disk plane occurs more efficiently as compared with…
The inverse Compton scattering of interstellar photons off cosmic-ray electrons seems to play a more important role in the generation of diffuse emission from the Galaxy than thought before. The background radiation field of the Galaxy is…
High resolution simulations reveal that in the cold dark matter scenario the structures form hierarchically and a large number of substructures survive in the galactic halos. The substructures can be probed if they emit gamma rays via dark…
The determination of the densities of intergalactic photons from the FIR to the UV produced by stellar emission and dust reradiation at various redshifts can provide an independent measure of the star formation history of the universe. High…
Analytical calculations and recent numerical experiments have shown that a sizable of the mass in our Galaxy is in a form of clumpy, virialized substructures that, according to \cite{dms:05}, can be as light as $10^{-6} \msun$. In this work…
An extensive program for the calculation of galactic cosmic-ray propagation has been developed. Primary and secondary nucleons, primary and secondary electrons, and secondary positrons are included. The basic spatial propagation mechanisms…
If weakly-interacting massive particles (WIMPs) make up the galactic dark matter halo, high densities of such particles would exist near massive bodies, such as the sun. The resulting annihilations are believed to produce neutrinos, gamma…
A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei (AGN) or to potentially low iron abundances as possible evidence for the spallation of iron. With the…
Optical/UV photons and even harder radiation components in galaxies are absorbed and scattered by dust and re-emitted at infrared wavelengths. For a better understanding of the obscured regions of the galaxies detailed models of the…
If dark matter is composed of neutralinos, one of the most exciting prospects for its detection lies in observations of the gamma-ray radiation created in pair annihilations between neutralinos, a process that may contribute significantly…
Dark Matter annihilations after recombination and during the epoch of structure formation deposit energy in the primordial intergalactic medium, producing reionization and heating. We investigate the constraints that are imposed by the…
The production and propagation of light antimatter nuclei has been calculated using inclusive antiproton production cross sections from a new data analysis, and coalescence models for the production of composite particles. Particles were…
The first detection of a gamma ray line with an energy of about 500 keV from the center our Galaxy dates back to the early seventies. Thanks to the astrophysical application of high spectral resolution detectors, it was soon clear that this…
Radioactive decay of unstable atomic nuclei leads to liberation of nuclear binding energy in the forms of gamma-ray photons and secondary particles (electrons, positrons); their energy then energises surrounding matter. Unstable nuclei are…
Gamma-ray instrumentation for astronomical spectroscopy consists of multiple-interaction detectors in space combined with sophisticated post-processing of detector events on ground. Spectral signatures in the MeV regime originate from…
Electrons densities in different locations of our galaxy are obtained in pulsar astronomy by dividing the dispersion measure (DM) by the distance of the pulsar to Earth. The properties of the interstellar plasma are related to its heating.…
We examine the annihilation of positrons on polycyclic aromatic hydrocarbon (PAH) molecules in interstellar medium conditions. We estimate the annihilation rates of positrons on PAHs by a semi-empirical approach. We show that PAHs can play…