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Related papers: Galactic Positron Excess from Selectively Enhanced…

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Recent observations of the Galactic center with ground based gamma-ray instruments have revealed a TeV (10$^{12}$ eV) gamma-ray signal consistent with the position of Sgr A*. The derived luminosity of the signal above 1 TeV is a few…

Astrophysics · Physics 2010-11-05 D. Horns

The detection of byproducts from particle annihilations in galactic halos would provide important information about the nature of the dark matter. Observational evidence for a local excess of high-energy positrons has motivated recent…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Brant Robertson , Andrew Zentner

The SPI spectrometer aboard of the INTEGRAL satellite has released a map of the e+e- annihilation emission line of unprecedented quality, showing that most of the photons arise from a region coinciding with the stellar bulge of the Milky…

Astrophysics · Physics 2009-11-11 Michel Casse , Pierre Fayet

Predefined spatial templates to describe the background of $\gamma$-ray emission from astrophysical processes, like cosmic ray interactions, are used in previous searches for the $\gamma$-ray signatures of annihilating galactic dark matter.…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Xiaoyuan Huang , Torsten Enßlin , Marco Selig

There is convincing observational evidence for an increasing cosmic-ray positron-to-electron ratio at energies larger than $\sim 10$~GeV, at odds with expectations from secondary positron production. The most recent AMS-02 data exhibit an…

High Energy Physics - Phenomenology · Physics 2019-03-21 Stefano Profumo , Farinaldo Queiroz , Clarissa Siqueira

A combined interpretation of the CALET $e^+\, +\, e^-$ spectrum up to 3 TeV and the AMS-02 positron spectrum up to 500 GeV was performed and the results are discussed. To parametrize the background electron flux, we assume a smoothly broken…

High Energy Astrophysical Phenomena · Physics 2018-10-23 S. Bhattacharyya , H. Motz , Y. Asaoka , S. Torii

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

If dark matter annihilates into standard model particles with a cross-section which is velocity dependent, then Local Group dwarf galaxies will not be the best place to search for the resulting gamma ray emission. A greater flux would be…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Andrija Kostić , Deaglan J. Bartlett , Harry Desmond

Sommerfeld-enhanced dark matter (DM) annihilation through $s$-wave has been widely considered as a consistent explanation for both the observed cosmic-ray (CR) positron excess and the DM thermal relic density. However, as the $s$-wave…

High Energy Physics - Phenomenology · Physics 2021-09-29 Yu-Chen Ding , Yu-Lin Ku , Chun-Cheng Wei , Yu-Feng Zhou

The EGRET excess in the diffuse galactic gamma ray data above 1 GeV shows all features expected from Dark Matter WIMP Annihilation: a)it is present and has the same spectrum in all sky directions, not just in the galactic plane. b) The…

Astrophysics · Physics 2007-05-23 W. de Boer

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…

High Energy Astrophysical Phenomena · Physics 2015-10-27 Mathieu Boudaud

The PAMELA and Fermi measurements of the cosmic-ray electron and positron spectra have generated much interest over the past two years, because they are consistent with a significant component of the electron and positron fluxes between 20…

High Energy Physics - Phenomenology · Physics 2011-08-05 Spencer Chang , Lisa Goodenough

AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels,…

High Energy Physics - Phenomenology · Physics 2016-02-17 Yu-Heng Chen , Kingman Cheung , Po-Yan Tseng

Due to their higher concentrations and small internal velocities, Milky Way subhalos can be at least as important as the smooth halo in accounting for the GeV positron excess via dark matter annihilation. After showing how this can be…

High Energy Astrophysical Phenomena · Physics 2010-08-13 Matthew D. Kistler , Jennifer M. Siegal-Gaskins

Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been…

Astrophysics · Physics 2009-10-06 T. Delahaye , F. Donato , N. Fornengo , J. Lavalle , R. Lineros , P. Salati , R. Taillet , .

Several independent observations of the galactic core suggest hitherto unexplained sources of energy. The most well known case is the 511 keV line which has proven very difficult to explain with conventional astrophysical positron sources.…

Astrophysics · Physics 2009-06-23 Kyle Lawson , Ariel R. Zhitnitsky

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…

Astrophysics · Physics 2007-05-23 I. V. Moskalenko , A. W. Strong

Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section. Depending on the assumptions made regarding cosmic ray…

High Energy Astrophysical Phenomena · Physics 2015-03-19 Dan Hooper , Tim Linden , Philipp Mertsch

It has been proposed that the excess in cosmic ray positrons at approximately 8 GeV, observed on both flights of the HEAT balloon experiment, may be associated with the annihilation of dark matter within the Milky Way halo. In this paper we…

Astrophysics · Physics 2008-11-26 Daniel T. Cumberbatch , Joseph Silk

Annihilation of dark matter can result in the production of stable Standard Model particles including electrons and positrons that, in the presence of magnetic fields, lose energy via synchrotron radiation, observable as radio emission.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Emma Storm , Tesla E. Jeltema , Stefano Profumo , Lawrence Rudnick