The 27th European Cosmic Ray Symposium

Results on mass composition of cosmic rays as measured with LOFAR

26 Jul 2022, 14:00

15m

oral CRI Parallel 1

Speaker

Arthur Corstanje (Vrije Universiteit Brussel)

Description

We present an updated analysis of the mass composition of cosmic rays in the ${10}^{17}$ to ${10}^{18}$ eV energy range. It is based on radio measurements of the depth of shower maximum $X_{\mathrm{m}\mathrm{a}\mathrm{x}}$, done with the LOFAR telescope.
We review the improvements to the reconstruction setup based on Corsika/CoREAS simulations, as well as the selection method to obtain a minimally biased $X_{\mathrm{m}\mathrm{a}\mathrm{x}}$-dataset. Systematic uncertainties on Xmax have been lowered to an estimated 7 to 9 g/cm${}^2$, at a resolution of 20 g/cm${}^2$ per shower.
Results include estimates of the mean and standard deviation of the $X_{\mathrm{m}\mathrm{a}\mathrm{x}}$-distribution. A statistical analysis at distribution level has been done as well, using a four-component model of light to heavy nuclei.
It confirms our previous results showing a significant low-mass fraction in this energy range.
We discuss consistency with existing results on $X_{\mathrm{m}\mathrm{a}\mathrm{x}}$ and mass composition.

Presentation materials

Corstanje_ECRS2022_LOFAR_Masscomposition.pdf