High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

Abstract

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System (H.E.S.S.), covering two orders of magnitude in energy and reaching a proton rejection power of better than $10^4$. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from ${\Gamma }_1=3.25$ $\pm$ 0.02 (stat) $\pm$ 0.2 (sys) to ${\Gamma }_2=4.49$ $\pm$ 0.04 (stat) $\pm$ 0.2 (sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms.

arXiv commentmain paper: 8 pages, 4 figures, supplemental material: 12 pages, 14 figures, accepted for publication in Physical Review Letters https://journals.aps.org/prl/

References in corpus (31)

• Observation of an anomalous positron abundance in the cosmic radiation
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Production and propagation of cosmic-ray positrons and electrons
• Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium
• The energy spectrum of cosmic-ray electrons at TeV energies
• Measurement of separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope
• Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
• Probing the ATIC peak in the cosmic-ray electron spectrum with H.E.S.S
• The H.E.S.S. Galactic plane survey
• Fermi LAT observations of cosmic-ray electrons from 7 GeV to 1 TeV
• A high performance likelihood reconstruction of gamma-rays for Imaging Atmospheric Cherenkov Telescopes
• Cosmic ray acceleration and escape from supernova remnants
• Measurement of the cosmic-ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite
• The Most Likely Sources of High Energy Cosmic-Ray Electrons in Supernova Remnants
• Cosmic-ray electron+positron spectrum from 7 GeV to 2 TeV with the Fermi Large Area Telescope
• Galactic electrons and positrons at the Earth:new estimate of the primary and secondary fluxes
• Interpretation of AMS-02 electrons and positrons data
• Escaping the accelerator; how, when and in what numbers do cosmic rays get out of supernova remnants?
• Diffuse Galactic gamma-ray emission with H.E.S.S
• Lessons from HAWC PWNe observations: the diffusion constant is not a constant; Pulsars remain the likeliest sources of the anomalous positron fraction; Cosmic rays are trapped for long periods of time in pockets of inefficient diffusion
• Positron flux and gamma-ray emission from Geminga pulsar and pulsar wind nebula
• Galactic factories of cosmic-ray electrons and positrons
• Impact of aerosols and adverse atmospheric conditions on the data quality for spectral analysis of the H.E.S.S. telescopes
• Measurement of Cosmic-ray Electrons at TeV Energies by VERITAS
• Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data
• Dipole anisotropy in cosmic electrons and positrons: inspection on local sources
• Stochastic cosmic ray sources and the TeV break in the all-electron spectrum
• A local fading accelerator and the origin of TeV cosmic ray electrons
• A Run-Wise Simulation and Analysis Framework for Imaging Atmospheric Cherenkov Telescope Arrays
• Direct Measurement of the Spectral Structure of Cosmic-Ray Electrons+Positrons in the TeV Region with CALET on the International Space Station
• Monte Carlo Study of Electron and Positron Cosmic-Ray Propagation with the CALET Spectrum

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