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Related papers: Diffuse cosmic gamma-rays at 1-20 MeV: A trace of …

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The origin of the cosmic gamma-ray background at 1-20 MeV remains a mystery. We show that gamma-ray emission accompanying annihilation of 20 MeV dark matter particles explains most of the observed signal. Our model satisfies all of the…

Astrophysics · Physics 2009-11-13 Kyungjin Ahn , Eiichiro Komatsu

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…

Astrophysics · Physics 2007-05-23 U. Schwanke

The all-sky surveys in gamma-rays by the imaging Compton telescope (COMPTEL) and the Energetic Gamma Ray Experiment Telescope (EGRET) on board the Compton Gamma Ray Observatory for the first time allows detailed studies of the extragalactic…

Astrophysics · Physics 2009-10-30 P. Sreekumar , F. W. Stecker , S. C. Kappadath

The origin of the inner Galactic emission, measured by COMPTEL with a flux of $\sim 10^{-2} ~{\rm MeV~ cm}^{-2}~ {\rm s}^{-1}~ {\rm sr}^{-1}$ in the 1-30 MeV energy range from the inner Galactic region, has remained unsettled since its…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Naomi Tsuji , Yoshiyuki Inoue , Hiroki Yoneda , Reshmi Mukherjee , Hirokazu Odaka

Here is reviewed our current understanding of Galactic and extragalactic diffuse gamma-ray emission. The spectrum of the extragalactic gamma-ray background above 30 MeV can be well described by a power law with photon index s=2.1. In the…

Astrophysics · Physics 2007-05-23 Martin Pohl

The origin of the inner Galactic emission, measured by COMPTEL with a flux of $\sim ~ 10^{-2}$ MeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$ in the 1-30 MeV range, has remained unsettled since its discovery in 1994. We investigate the origin of this…

High Energy Astrophysical Phenomena · Physics 2023-06-02 Naomi Tsuji , Yoshiyuki Inoue , Hiroki Yoneda , Reshmi Mukherjee , Hirokazu Odaka

Over the past few decades, an anomalous 511 keV gamma-ray line has been observed from the centre of the Milky Way. Dark matter (DM) in the form of light weakly interacting massive particles (WIMPs) annihilating into electron-positron pairs…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-01 Ryan J. Wilkinson , Aaron C. Vincent , Celine Boehm , Christopher McCabe

We discuss the possibility that the recent detection of 511 keV gamma rays from the galactic bulge, as observed by INTEGRAL, can be naturally explained by the supermassive very dense droplets (strangelets) of dark matter. These droplets are…

High Energy Physics - Phenomenology · Physics 2009-11-10 David H. Oaknin , Ariel R. Zhitnitsky

Light Dark Matter (DM), defined here as having a mass between 1 MeV and about 1 GeV, is an interesting possibility both theoretically and phenomenologically, at one of the frontiers of current progress in the field of DM searches. Its…

High Energy Physics - Phenomenology · Physics 2022-07-06 Marco Cirelli , Nicolao Fornengo , Bradley J. Kavanagh , Elena Pinetti

Several independent observations of the Galactic core suggest hitherto unexplained sources of energy. We suggest that dark matter in the form of dense antimatter nuggets could provide a natural site for electron and proton annihilation,…

Astrophysics · Physics 2014-10-13 Michael McNeil Forbes , Ariel R. Zhitnitsky

The origin of both the diffuse high-latitude MeV gamma-ray emission and the 511 keV line flux from the Galactic bulge are uncertain. Previous studies have invoked dark matter physics to independently explain these observations, though as…

Astrophysics · Physics 2008-11-26 Jose A. R. Cembranos , Louis E. Strigari

The public data from the EGRET space telescope on diffuse galactic gamma rays in the energy range from 0.1 to 10 GeV show an excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. This excess…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. de Boer

The Galactic positrons, as observed by their annihilation gamma-ray line at 0.511 MeV, are difficult to account for with astrophysical sources. It has been proposed that they are produced instead by dark matter annihilation or decay in the…

Astrophysics · Physics 2009-07-09 John F. Beacom , Nicole F. Bell , Gianfranco Bertone

Diffuse Galactic gamma-ray emission is produced in interactions of cosmic rays with gas and ambient photon fields and thus provides us with an indirect measurement of cosmic rays in various locations in the Galaxy. The diffuse gamma-ray…

Astrophysics · Physics 2007-05-23 Martin Pohl

In this article, I summarize and discuss the body of evidence which has accumulated in favor of dark matter in the form of approximately 10 GeV particles. This evidence includes the spectrum and angular distribution of gamma rays from the…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-09 Dan Hooper

We propose that a dark matter (DM) spike around the Galactic Center's (GC) supermassive black hole, Sgr A*, could account for most of the bulge's measured 511 keV line intensity while remaining cosmologically compatible. DM annihilation can…

High Energy Astrophysical Phenomena · Physics 2025-09-08 Pedro De la Torre Luque , Shyam Balaji , Malcolm Fairbairn , Filippo Sala , Joseph Silk

It has been long discussed that cosmic rays may contain signals of dark matter. In the last couple of years an anomaly of cosmic-ray positrons has drawn a lot of attentions, and recently an excess in cosmic-ray anti-proton has been reported…

High Energy Physics - Phenomenology · Physics 2016-06-29 Shin'ichiro Ando , Koji Ishiwata

The morphology and characteristics of the so-called GeV gamma-ray excess detected in the Milky Way lead us to speculate about a possible common origin with the 511 keV line mapped by the SPI experiment about ten years ago. In the previous…

High Energy Astrophysical Phenomena · Physics 2014-08-05 Celine Boehm , Paolo Gondolo , Pierre Jean , Thomas Lacroix , Colin Norman , Joseph Silk

Very recently, a significant $\sim 20$ GeV gamma-ray excess in the Milky Way halo has been reported and a dark matter origin has been suggested. The inferred dark matter parameters are $ m_\chi \sim 0.5-0.8 $ TeV and $ \langle \sigma v…

High Energy Astrophysical Phenomena · Physics 2025-12-16 Xiao Wang , Kai-Kai Duan

We study the properties of the diffuse gamma-ray background around the Galactic plane at energies 20 -- 200 GeV. We find that the spectrum of this emission possesses significant spacial variations with respect to the average smooth…

High Energy Astrophysical Phenomena · Physics 2012-10-29 Alexey Boyarsky , Denys Malyshev , Oleg Ruchayskiy
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