相关论文: Annihilation Radiation in the Galaxy
A number of signals involving charged cosmic rays and high-energy photons have been interpreted as being due to annihilating dark matter. This article provides an overview of the experimental evidence and discusses in particular detections…
We analyse SPI/INTEGRAL data on the 511 keV line from the Galactic Centre, accumulated over ~6 years of observations. We decompose the X-ray and soft gamma-ray emission of the central part of the Milky Way into a relatively compact "Bulge"…
The most energetic part of the electromagnetic spectrum bears the purest clues to the synthesis of atomic nuclei in the universe. The decay of radioactive species, synthesized in stellar environments and ejected into the interstellar…
The electron and positron cosmic rays puzzle has triggered a revolution in the field of astroparticle physics. Many hypotheses have been proposed to explain the unexpected rise of the positron fraction, observed by HEAT and PAMELA…
[Abridged]. We take advantage of the galaxy-like 3D dark matter map extracted from the HORIZON Project results to calculate the positron and antiproton fluxes from dark matter annihilation, in a model-independent approach as well as for…
Maps of the Galactic electron-positron annihilation radiation show evidence for three distinct and significant features: (1) a central bulge source, (2) emission in the Galactic plane, and (3) an enhancement of emission at positive…
We calculate the flux of cosmic gamma rays expected {}from the annihilation of neutralinos in the Galactic halo. Our calculation of the annihilation cross section to two photons improves the existing calculations by inclusion of exact…
Indirect detection signals from dark matter annihilation are studied in the positron channel. We discuss in detail the positron propagation inside the galactic medium: we present novel solutions of the diffusion and propagation equations…
If dark matter (DM), which is considered to constitute most of the mass of galaxies, is made of supersymmetric (SUSY) particles, the centers of galaxies should emit gamma-rays produced by their self-annihilation. We present accurate…
Electron-positron annihilation line from a Galactic center direction was discovered by the balloon-borne germanium gamma-ray telescope, and confirmed by OSSE experiment of CGRO mission. Extensive observations by INTEGRAL observatory permit…
The positron fraction in cosmic rays was found to be a steadily increasing in function of energy, above $\sim$ 10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the…
Compton Gamma Ray Observatory, OSSE, SMM, TGRS, balloon and recent INTEGRAL data reveal a feature of the 0.511 MeV annihilation radiation of the Galactic Center with a flux of approximately 5x 10^{-4}~0.511 MeV photons cm^{-2} s^{-1}. We…
We study annihilation radiation of neutralinos in the Galactic centre, assuming the existence of a 'spike' in the dark matter density profile, due to adiabatic accretion onto the massive black hole lying at the Galactic centre. Under this…
We have made a calculation of the propagation of positrons from dark-matter particle annihilation in the Galactic halo for different models of the dark matter halo distribution using our 3D code. We show that the Green's functions are not…
The annihilation of cosmic positrons ($e^+$) with electrons in the interstellar medium (ISM) results in the strongest persistent gamma-ray line signal in the sky. For 50 years, this 511 keV emission has puzzled observers and theoreticians.…
The origin of the diffuse gamma-ray background in the range from hundreds keV to several MeV is not known conclusively. From current models and observations it is believed that, at least partially, this background is formed by blazars and…
Recent advances in gamma-ray cosmic ray, infrared and radio astronomy have allowed us to develop a significantly better understanding of the galactic medium properties in the last few years. In this work using the DRAGON code, that…
The positron fraction in cosmic rays was found to be steadily increasing in function of energy, above $\sim$10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the…
The excess energy emitted during the positronium (Ps) formation in condensed matter may be released as light. Spectroscopic analysis of this light can be a new method of studying the electronic properties of materials. We report the first…
Measurement and astrophysical interpretation of characteristic gamma-ray lines from nucleosynthesis was one of the prominent science goals of the INTEGRAL mission and in particular its spectrometer SPI. Emission from 26Al and from 60Fe…