Abstract

Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the gamma-ray emission from Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range similar to 90 GeV-6 TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68 +/- 0.04 and 2.61 +/- 0.08 above similar to 200 GeV, respectively.

Autore Pugliese

• Loparco Francesco , Giordano Francesco , Fusco Piergiorgio , Raino' Silvia

Tutti gli autori

• LOPARCO F.;GIORDANO F.;FUSCO P.;RAINO' S.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2014

ISSN

0031-9007

ISBN

Non Disponibile

Numero di citazioni Wos

17

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

18

Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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