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Related papers: $e^\pm$ Excesses in the Cosmic Ray Spectrum and Po…

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We isolated the anomalous part of the cosmic electron-positron flux within a Bayesian likelihood analysis. Using 219 recent cosmic ray spectral data points, we inferred the values of selected cosmic ray propagation parameters. In the…

High Energy Astrophysical Phenomena · Physics 2012-04-25 Katie Auchettl , Csaba Balázs

In a recently proposed model the cosmic rays spectrum at energies above EeV can be fitted with a minimal number of unknown parameters assuming that the extragalactic cosmic rays are only protons with a power law source spectrum. Within this…

Astrophysics · Physics 2007-06-27 O. Kalashev , G. Gelmini , D. Semikoz

We present a measurement of the cosmic-ray electron+positron spectrum between 7 GeV and 2 TeV performed with almost seven years of data collected with the Fermi Large Area Telescope. We find that the spectrum is well fit by a broken power…

Observations by the Fermi-LAT have uncovered a bright, spherically symmetric excess surrounding the center of the Milky Way galaxy. The spectrum of the gamma-ray excess peaks sharply at an energy ~2 GeV, exhibiting a hard spectrum at lower…

High Energy Astrophysical Phenomena · Physics 2017-02-28 Tim Linden , Nicholas L. Rodd , Benjamin R. Safdi , Tracy R. Slatyer

We use multi-component decaying dark matter (DM) scenario to explain the possible cosmic ray excesses in the positron fraction recently confirmed by AMS-02 and the total $e^+ +e^-$ flux observed by Fermi-LAT. In the two-component DM models,…

High Energy Physics - Phenomenology · Physics 2014-12-01 Chao-Qiang Geng , Da Huang , Lu-Hsing Tsai

Recent works of [1402.2301,1402.4119], claiming the detection of extra emission line with energy ~3.5 keV in X-ray spectra of certain clusters of galaxies and nearby Andromeda galaxy, have raised considerable interest in astrophysics and…

High Energy Astrophysical Phenomena · Physics 2015-08-26 Dmytro Iakubovskyi

We propose to test the dark matter (DM) interpretation of the positron excess observed by the PAMELA cosmic-ray (CR) detector through the identification of a Galactic diffuse gamma-ray component associated to DM-induced prompt and radiative…

Astrophysics of Galaxies · Physics 2009-09-01 Marco Regis , Piero Ullio

A GeV gamma-ray excess has possibly been individuated in Fermi-LAT data from the Galactic Center and interpreted in terms of Dark Matter (DM) annihilations, either in hadronic (essentially $b\bar{b}$) or leptonic channels. In order to test…

High Energy Physics - Phenomenology · Physics 2015-06-22 Marco Cirelli , Daniele Gaggero , Gaëlle Giesen , Marco Taoso , Alfredo Urbano

The public data from the EGRET space telescope on diffuse Galactic gamma rays in the energy range from 0.1 to 10 GeV are reanalyzed with the purpose of searching for signals of Dark Matter annihilation (DMA). The analysis confirms the…

Astrophysics · Physics 2009-11-13 W. de Boer , C. Sander , V. Zhukov , A. V. Gladyshev , D. I. Kazakov

The excess of cosmic-ray electron and positron fluxes measured by the PAMELA satellite and ATIC balloon experiments may be interpreted as the signals of the dark matter annihilation or decay into leptons. In this letter we show that the…

High Energy Physics - Phenomenology · Physics 2010-04-30 Junji Hisano , Masahiro Kawasaki , Kazunori Kohri , Kazunori Nakayama

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 , .

Pulsars have been invoked to explain the origin of recently observed high-energy Galactic cosmic-ray positrons. Since the positron propagation distance decreases with energy, the number of pulsars that can contribute to the observed…

High Energy Astrophysical Phenomena · Physics 2018-07-18 Ilias Cholis , Tanvi Karwal , Marc Kamionkowski

The region around the Galactic center (GC) is now well established to be brighter at energies of a few GeV than expected from conventional models of diffuse gamma-ray emission and catalogs of known gamma-ray sources. We study the GeV excess…

High Energy Astrophysical Phenomena · Physics 2017-06-27 LAT Collaboration

If sub-GeV Dark matter(DM) annihilates to the charged particles such as $e^+ e^-$, $\mu^+ \mu^-$, or $\pi^+ \pi^-$, it generates an additional source of electrons and positrons in the cosmic ray (CR) population within our Milky Way. During…

High Energy Astrophysical Phenomena · Physics 2025-12-10 Guansen Wang , Bing-Yu Su , Lei Zu , Lei Feng

Astrophysical and cosmological observations do not require the dark matter particles to be absolutely stable. If they are indeed unstable, their decay into positrons might occur at a sufficiently large rate to allow the indirect detection…

High Energy Physics - Phenomenology · Physics 2011-05-05 Alejandro Ibarra , David Tran

Recently, tentative evidence for an excess of gamma rays at energies around 130 GeV has been reported from analyses of data from the Fermi Large Area Telescope (LAT). The excess is potentially of great interest, as it could be associated…

High Energy Astrophysical Phenomena · Physics 2012-07-04 Stefano Profumo , Tim Linden

Recently, dark matter indirect searches have gained a lot of attention, mostly due to the possibility of recent anomalies in cosmic rays and microwave sky maps being due to the annihilation or decay of dark matter. In this thesis, we argue…

High Energy Astrophysical Phenomena · Physics 2010-12-21 Philipp Mertsch

The PAMELA and ATIC collaborations have recently reported an excess in the cosmic ray positron and electron fluxes. These lepton anomalies might be related to cold dark matter (CDM) particles annihilating within a nearby dark matter clump.…

High Energy Astrophysical Phenomena · Physics 2009-09-01 Pierre Brun , Timur Delahaye , Juerg Diemand , Stefano Profumo , Pierre Salati

Observations of cosmic-ray electrons and positrons have been made with a new balloon-borne detector, HEAT (the "High-Energy Antimatter Telescope"), first flown in 1994 May from Fort Sumner, NM. We describe the instrumental approach and the…

Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. Several signatures, ranging from the positron excess, as observed…

Astrophysics · Physics 2009-11-13 W. de Boer