Energy spectra of elemental groups of cosmic rays: Update on the KASCADE unfolding analysis

Abstract

Keywords:Cosmic ray energy spectrum Cosmic ray composition The knee KASCADE Hadronic interaction models FLUKA GHEISHA a b s t r a c tThe KASCADE experiment measures extensive air showers induced by cosmic rays in the energy range around the so-called knee. The data of KASCADE have been used in a composition analysis showing the knee at 3-5 PeV to be caused by a steepening in the light-element spectra [T. Antoni et al., (KASCADE Coll.), Astropart. Phys. 24 (2005) 1-25]. Since the applied unfolding analysis depends crucially on simulations of air showers, different high-energy hadronic interaction models (QGSJet and SIBYLL) were used. The results have shown a strong dependence of the relative abundance of the individual mass groups on the underlying model. In this update of the analysis we apply the unfolding method with a different low energy interaction model (FLUKA instead of GHEISHA) in the simulations. While the resulting individual mass group spectra do not change significantly, the overall description of the measured data improves by using the FLUKA model. In addition data in a larger range of zenith angle are analysed. The new results are completely consistent, i.e. there is no hint to any severe problem in applying the unfolding analysis method to KASCADE data.

A study on the sharp knee and fine structures of cosmic ray spectra

“…Especially interesting signature of the Tibet result is that the CR spectra show a very sharp break of the spectrum index around 4 PeV. At almost the same time several experiments have reported their new measurements with the similar behavior, such as KASKADE [14], ARAGATS-GAMMA [15], Yakutsk [16], and MAKET-ANI [17]. Such a sharp knee challenges the traditional interpretations of the knee [18][19][20].…”

Cosmic ray physics with ARGO-YBJ

“…The origin of the knee and the transition between galactic and extragalactic origin are still under discussion. In the standard picture the origin of the knee is related to a decrease of the flux of protons and He nuclei [4]. Several experiments reported an evidence that the knee of the all-particle spectrum is due to nuclei heavier than Helium.…”

Origin of Ultra-High-Energy Galactic Cosmic Rays: The Isotropy Problem

“…We use data of the Kascade-Grande Collaboration (Apel et al 2009;ArteagaVelázquez et al 2010), ranging from 2 PeV to 0.5 EeV, HiRes monocular data between 0.2 EeV and 3 EeV (Abbasi et al 2005), and the Auger Collaboration (Pierre AUGER Collaboration et al 2010) above 1 EeV.…”