ORIGIN OF THE COSMIC-RAY SPECTRAL HARDENING
By N. Tomassetti. 2012
150 citations recorded by the source corpus.
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−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.
Subfields: Atmospheric Science, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/d916b40078ab55cdf51a1d82e358ee050631d127
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In Nuclear and High Energy Physics
- J. Rachen
- U. Firenze
- E. Amato
- Gran Sasso Science Institute
- P. S. A. A. D. Arcetri
- A. V. Vliet
- S. Buitink
- Heino Falcke
Citations in the corpus
- Cosmic-ray energy spectrum and composition up to the ankle - the case for a second Galactic component (2016, background): “…in the source spectrum of cosmic rays (Biermann et al. 2010a; Ohira et al. 2011; Yuan et al. 2011; Ptuskin et al. 2013), as a propagation e↵ect (Tomassetti 2012; Blasi et al. 2012), the e↵ect of re-acceleration by weak shocks (Thoudam & Hörandel 2014) or the e↵ect of nearby sources (Thoudam &…”
- Cosmic ray transport in the Galaxy: A review (2017, background): “…of He nuclei, whose spectrum is harder than that of protons; 3) as discussed by Blasi et al. (2012); Aloisio & Blasi (2013); Aloisio et al. (2015); Tomassetti (2012), the reason for harder nuclear spectra may reside in a change of slope of the diffusion coefficient experienced by particles,…”
- The origin of galactic cosmic rays (2013, unknown): “For instance, Tomassetti (2012) showed that a spatially dependent diffusion coefficient may induce a spectral hardening under some assumptions on the functional shape of the function representing the diffusion coefficient (nonseparability between energy and space coordinates is required).”