Related papers: Gamma-Rays from Positron Annihilation
The origin of the X-ray emission from the central region of the Galaxy has remained a mystery, despite extensive study over the past two decades. A fundamental question is the relative contribution of the point-source and diffuse components…
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…
The measurement of gamma rays from cosmic sources at MeV energies is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and their impacts on objects and phenomena throughout the universe. Gamma rays trace…
The Galactic Bulge region is a rich host of variable high-energy point sources. These sources include bright and relatively faint X-ray transients, X-ray bursters, persistent neutron star and black-hole candidate binaries, X-ray pulsars,…
Even 50 years after the discovery of a positron annihilation line from the inner Galaxy, no class of astrophysical sources has emerged as a definitive explanation for both the emission morphology and flux. Positrons produced by dark matter…
Pulsars are factories of relativistic electrons and positrons that propagate away from the pulsar, permeating later our Galaxy. The acceleration and propagation of these particles are a matter of intense debate. In the last few years, we…
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…
We study the gamma rays observed by the Fermi Gamma Ray Space Telescope from the direction of the Galactic Center and find that their angular distribution and energy spectrum are well described by a dark matter annihilation scenario. In…
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…
"Diffuse" gamma rays consist of several components: truly diffuse emission from the interstellar medium, the extragalactic background, whose origin is not firmly established yet, and the contribution from unresolved and faint Galactic point…
We study the annihilating dark matter contribution to the extra-galactic diffuse gamma-ray background spectrum, motivated by the recent observations of cosmic-ray positron/electron anomalies. The observed diffuse gamma-ray flux provides…
During the Core Programme, INTEGRAL has surveyed a large portion of the sky (around 9000 square degrees); although INTEGRAL is not optimized for extra-galactic studies its observations have nevertheless given us the opportunity to explore…
The nature of Dark Matter remains one of the outstanding questions of modern astrophysics. The success of the Cold Dark Matter cosmological model argues strongly in favor of a major component of the dark matter being in the form of…
Significant advances have been made in the understanding of the diffuse Galactic hard X-ray continuum emission using data from the INTEGRAL observatory. The diffuse hard power-law component seen with the INTEGRAL/SPI spectrometer has been…
The region surrounding the center of the Milky Way is both astrophysically rich and complex, and is predicted to contain very high densities of dark matter. Utilizing three years of data from the Fermi Gamma Ray Space Telescope (and the…
Al(26) radioactivity traces recent nucleosynthesis throughout the Galaxy, and is known to be produced in massive stars and novae. The map from its decay gamma-ray line suggests massive stars to dominate, but high-resolution line…
We present the preliminary results of the observational campaign performed in 2003 to study the Galactic Nucleus with INTEGRAL. The mosaicked images obtained with the IBIS/ISGRI coded aperture instrument in the energy range above 20 keV,…
A spherical-symmetric gamma-ray emission from the central region of the Galaxy has been recently identified in Fermi-LAT data, and initially associated to dark matter particle annihilations. Guided by the evidence for a high gas density in…
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…
Cosmic nucleosynthesis co-produces unstable isotopes, which emit characteristic gamma-ray emission lines upon their radioactive decay that can be measured with SPI on INTEGRAL. High spectral resolution allows to derive velocity constraints…