Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

THE PIERRE AUGER OBSERVATORY (PATRICIA HANSEN PERTENECE A LA COLABORACION)

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2017

1475-7516

We present a combined fit of a simple astrophysical model of UHECR sourcesto both the energy spectrum and mass composition data measured by the Pierre AugerObservatory. The fit has been performed for energies above 5 · 1018 eV, i.e. the region ofthe all-particle spectrum above the so-called ?ankle? feature. The astrophysical model weadopted consists of identical sources uniformly distributed in a comoving volume, where nucleiare accelerated through a rigidity-dependent mechanism. The fit results suggest sourcescharacterized by relatively low maximum injection energies, hard spectra and heavy chemicalcomposition. We also show that uncertainties about physical quantities relevant to UHECRpropagation and shower development have a non-negligible impact on the fit results.