ORIGIN OF THE COSMIC-RAY SPECTRAL HARDENING

Journal Article · Sun Jun 10 04:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/752/1/L13· OSTI ID:22047757

Tomassetti, Nicola ^[1]

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1. INFN-Sezione di Perugia, 06122 Perugia (Italy)

Recent data from ATIC, CREAM, and PAMELA indicate that the cosmic-ray energy spectra of protons and nuclei exhibit a remarkable hardening at energies above 100 GeV nucleon{sup -1}. We propose that the hardening is an interstellar propagation effect that originates from a spatial change of the cosmic-ray transport properties in different regions of the Galaxy. The key hypothesis is that the diffusion coefficient is not separable into energy and space variables as usually assumed. Under this scenario, we can reproduce the observational data well. Our model has several implications for cosmic-ray acceleration/propagation physics and can be tested by ongoing experiments such as the Alpha Magnetic Spectrometer or Fermi-LAT.

• OSTI ID: 22047757
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 752; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
ASTROPHYSICS
COSMIC NUCLEI
COSMIC PROTONS
COSMIC RAY PROPAGATION
DIFFUSION
ENERGY SPECTRA
GEV RANGE
MAGNETIC SPECTROMETERS
MILKY WAY
SPECTRAL HARDENING
TURBULENCE