Cosmic Ray Mass Measurements with LOFAR
1 Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, ( Belgium )
2 Department of Astrophysics/IMAPP, Radboud University, P.O. Box 9010, 6500 GL Nijmegen, ( the Netherlands )
3 Astron, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, ( The Netherlands )
4 Nikhef, Science Park 105, 1098 XG Amsterdam, ( The Netherlands )
5 University of California Irvine, Irvine, CA 92697, ( USA )
6 KVI-CART, Zernikelaan 25, 9747 AA Groningen, ( The Netherlands )
7 University of Groningen, Zernikelaan 25, 9747 AA Groningen, ( The Netherlands )
* e-mail: Stijn.Buitink@vub.ac.be
Published online: 15 March 2017
In the dense core of LOFAR individual air showers are detected by hundreds of dipole antennas simultaneously. We reconstruct Xmax by using a hybrid technique that combines a two-dimensional fit of the radio profile to CoREAS simulations and a one-dimensional fit of the particle density distribution. For high-quality detections, the statistical uncertainty on Xmax is smaller than 20 g/cm2. We present results of cosmic-ray mass analysis in the energy regime of 1017 - 1017.5 eV. This range is of particular interest as it may harbor the transition from a Galactic to an extragalactic origin of cosmic rays.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.