相关论文: Diffuse Galactic antimatter from faint thermonucle…
The annihilation of positrons in the Galaxy's interstellar medium produces characteristic gamma-rays with a line at 511 keV. This emission has been observed with the spectrometer SPI on INTEGRAL, confirming a puzzling morphology with bright…
In this paper we calculate the Galactic positron flux from dark matter annihilation in the frame of supersymmetry, taking the enhancement of the flux by existence of dark matter substructures into account. The propagation of positrons in…
The first detected gamma-ray line originating from outside the solar system is the 511 keV emission from the center of our Galaxy. The widely accepted explanation attributes this signal to electron-positron annihilation. However, despite…
We study the origin of the positron excess observed in the local cosmic-ray spectrum at high energies, and relate it to the cosmic rays and gamma-ray emission across the entire Galaxy. In particular, we explore the hypothesis of a single,…
Microquasars are stellar-mass black holes accreting matter from a companion star and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of $10^6$ to $10^{10}$ solar masses.…
Historical Type Ia supernovae are a leading candidate for the source of positrons observed through their diffuse annihilation emission in the Galaxy. However, search for annihilation emission from individual Type Ia supernovae has not been…
Clusters of galaxies are enriched with positrons from jets of active galactic nuclei (AGNs) or from the interaction of cosmic rays with the intracluster gas. We follow the cooling of these positrons and show that their eventual annihilation…
The imaging spectrometer SPI on board ESA's INTEGRAL observatory provides us with an unprecedented view of positron annihilation in our Galaxy. The first sky maps in the 511 keV annihilation line and in the positronium continuum from SPI…
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…
Radioactive nuclei, especially those created in SN explosion, have long been suggested to be important contributors of galactic positrons. In this paper we describe the findings of three independent OSSE/SMM/TGRS studies of positron…
The observation of a strong and extended positron-electron line annihilation emission in the central regions of the Galaxy by INTEGRAL-SPI, consistent with the Galactic bulge geometry, without any counterpart in the gamma-ray range, neither…
The region of the Galactic center contains several sources which demonstrate their activity at various wavelengths and particularly above several hundred keV. Escape of positrons from such a source or several sources into the interstellar…
The signature of positron annihilation, namely the 511 keV $\gamma$-ray line, was first detected coming from the direction of the Galactic center in the 1970's, but the source of Galactic positrons still remains a puzzle. The measured flux…
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…
A promising source of the positrons that contribute through annihilation to the diffuse Galactic 511keV emission is the beta-decay of unstable nuclei like 56Ni and 44Ti synthesised by massive stars and supernovae. Although a large fraction…
Positrons are known to be produced in interactions between cosmic-ray nuclei and interstellar matter ("secondary production"). Positrons may, however, also be created by dark matter particle annihilations in the galactic halo or in the…
We use 15 years of $\gamma$-ray data from INTEGRAL/SPI in a refined investigation of the morphology of the Galactic bulge positron annihilation signal. Our spatial analysis confirms that the signal traces the old stellar population in the…
It is shown that the antiproton spectrum reported by the AMS02 collaboration can be accounted for by dark matter (DM) decay if the residence time in the Galactic halo is of order 90 Myr. The DM lifetime assumed, $ 5 \cdot 10^{27}$ s for DM…
The excess of continuum gamma-ray emission from the Galaxy above 1 GeV is an unsolved puzzle. It may indicate that the interstellar nucleon or electron spectra are harder than local direct measurements, as could be the case if a local…
We present the energy spectra of the fluxes of positrons, anti-protons and photons generated by Dark Matter annihilations in our galaxy, as univocally predicted by the model of Minimal Dark Matter. Due to multi-TeV masses and to the…