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Open AccessJournal ArticleDOI

Probing the ATIC peak in the cosmic-ray electron spectrum with H.E.S.S.

Felix Aharonian, +168 more
- 01 Dec 2009 - 
- Vol. 508, Iss: 2, pp 561-564
TLDR
In this article, the authors present a measurement of the cosmic-ray electron spectrum with H.E.S. starting at 340 GeV and show no indication of a structure in the electron spectrum, but rather a power-law spectrum with spectral index of 3.0 +- 0.1 (stat.) + − 0.3 (syst.) which steepens at about 1 TeV.
Abstract
The measurement of an excess in the cosmic-ray electron spectrum between 300 and 800 GeV by the ATIC experiment has - together with the PAMELA detection of a rise in the positron fraction up to 100 GeV - motivated many interpretations in terms of dark matter scenarios; alternative explanations assume a nearby electron source like a pulsar or supernova remnant. Here we present a measurement of the cosmic-ray electron spectrum with H.E.S.S. starting at 340 GeV. The H.E.S.S. data with their lower statistical errors show no indication of a structure in the electron spectrum, but rather a power-law spectrum with spectral index of 3.0 +- 0.1 (stat.) +- 0.3 (syst.) which steepens at about 1 TeV.

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Citations
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Giant gamma-ray bubbles from fermi-lat: active galactic nucleus activity or bipolar galactic wind?

TL;DR: The gamma-ray emission associated with these bubbles has a significantly harder spectrum (dN/dE ~ E 2) than the inverse Compton emission from electrons in the Galactic disk, or the gamma rays produced by the decay of pions from proton-interstellar medium collisions.
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Freeze-in production of FIMP dark matter

TL;DR: In this paper, the authors propose an alternate, calculable mechanism of dark matter genesis, "thermal freeze-in", involving a Feebly Interacting Massive Particle (FIMP) interacting so feebly with the thermal bath that it never attains thermal equilibrium.
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Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

M. Aguilar, +294 more
TL;DR: In this paper, a precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1.GV to 1.8TV is presented based on 300 million events.
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Fermi-LAT observations of the diffuse γ-ray emission: implications for cosmic rays and the interstellar medium

Markus Ackermann, +179 more
TL;DR: In this paper, a grid of models is created by varying within observational limits the distribution of cosmic-ray sources, the size of the cosmicray confinement volume (halo), and distribution of interstellar gas.
Journal ArticleDOI

The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV

Markus Ackermann, +177 more
TL;DR: The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV.
References
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Journal ArticleDOI

An excess of cosmic ray electrons at energies of 300-800 GeV

TL;DR: An excess of galactic cosmic-ray electrons at energies of ∼300–800 GeV is reported, which indicates a nearby source of energetic electrons, or the electrons could arise from the annihilation of dark matter particles.
Journal ArticleDOI

Measurement of the Cosmic Ray e+ + e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope.

A. A. Abdo, +201 more
TL;DR: In this article, the Fermi Large Area Telescope (Fermi LAT) was used to detect the electron spectrum up to 1 TeV using a diffusive model and a potential local extra component.
Journal ArticleDOI

The status of the HESS project

TL;DR: The High Energy Stereoscopic System (HESS) is a system of four, 107 m2 mirror area, imaging Cherenkov telescopes under construction in the Khomas Highland of Namibia (1800 m asl) as mentioned in this paper.
Journal ArticleDOI

The Status of the H.E.S.S. Project

TL;DR: The High Energy Stereoscopic System (H.E.S.) as discussed by the authors is a system of four, 107 m^2 mirror area, imaging Cherenkov telescopes under construction in the Khomas Highland of Namibia (1800 m asl).
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