Detecting cosmic rays with the LOFAR radio telescope

P. Schellart (1) , A. Nelles (1) , S. Buitink (1) , A. Corstanje (1) , J. E. Enriquez (2) , H. Falcke (3, 4, 1) , W. Frieswijk (3) , J. R. Hörandel (1) , A. Horneffer (5) , C. W. James (6) , M. Krause (7) , M. Mevius (3) , O. Scholten (8) , S. ter Veen (9) , S. Thoudam (1) , M. van den Akker , A. Alexov (3) , J. Anderson (5) , I. M. Avruch (10) , L. Bähren (11) , R. Beck (12) , M. E. Bell , P. Bennema , M. J. Bentum (3) , G. Bernardi (13) , P. Best (14) , J. Bregman (3) , F. Breitling (15) , M. Brentjens (3) , J. Broderick (16) , M. Brüggen (17) , B. Ciardi (5) , A. Coolen (18) , F. de Gasperin (19) , E. de Geus (20) , A. de Jong (3) , M. de Vos , S. Duscha (3) , J. Eislöffel (21) , R. A. Fallows (22) , C. Ferrari (23) , M. A. Garrett (3, 24) , Jean-Mathias Griessmeier (25) , T. Grit , J. P. Hamaker , T. E. Hassall (26) , G. Heald (3) , J. W. T. Hessels (27) , M. Hoeft (21) , H. A. Holties (3) , M. Iacobelli (24) , E. Juette (28) , A. Karastergiou (29) , W. Klijn , J. Kohler (30) , V. I. Kondratiev (3) , M. Kramer (4) , M. Kuniyoshi (4) , G. Kuper (3) , P. Maat (3) , G. Macario (23) , G. Mann (15) , S. Markoff (11) , D. Mckay-Bukowski (31) , J. P. Mckean (3) , J. C. A. Miller-Jones (11) , J. D. Mol (32) , D. D. Mulcahy , H. Munk (3) , R. Nijboer , M. J. Norden , E. Orru (3) , R. Overeem , H. Paas (33) , M. Pandey-Pommier (34) , R. Pizzo (3) , A. G. Polatidis (3) , A. Renting , J. W. Romein , H. Röttgering (24) , A. Schoenmakers (3) , D. Schwarz (35) , J. Sluman (3) , O. Smirnov (36) , C. Sobey (4) , B. W. Stappers (26) , M. Steinmetz (15) , J. Swinbank (11) , Y. Tang (3) , C. Tasse (37, 38) , C. Toribio (3) , J. van Leeuwen (27) , R. van Nieuwpoort , R. J. van Weeren (3) , N. Vermaas , R. Vermeulen (3) , C. Vocks (15) , C. Vogt (3) , R. A. M. J. Wijers , S. J. Wijnholds (3) , M. W. Wise (11, 3) , O. Wucknitz (39) , S. Yatawatta (40) , P. Zarka (38) , A. Zensus (4)

1 Radboud University [Nijmegen]
2 SETI Institute
3 ASTRON - Netherlands Institute for Radio Astronomy
4 MPIFR - Max-Planck-Institut für Radioastronomie
5 Max Planck Institute for Astrophysics
6 ECAP - Erlangen Centre for Astroparticle Physics
7 MPE - Max-Planck-Institut für Extraterrestrische Physik
8 KVI - Kernfysisch Versneller Instituut, Univ. of Groningen
9 IMAPP - Institute for Mathematics, Astrophysics and Particle Physics
10 SRON - SRON Netherlands Institute for Space Research
11 AI PANNEKOEK - Astronomical Institute Anton Pannekoek
12 LCPM - Laboratoire de Chimie Physique Moléculaire
13 CfA - Harvard-Smithsonian Center for Astrophysics
14 University of Edinburgh
15 AIP - Leibniz-Institut für Astrophysik Potsdam
16 University of Southampton
17 Jacobs University [Bremen]
18 London Institute for Mathematical Sciences
19 Hamburger Sternwarte/Hamburg Observatory
20 Medstar Research Institute
21 TLS - Thüringer Landessternwarte Tautenburg
22 Institute of Mathematical and Physical Sciences
23 LAGRANGE - Joseph Louis LAGRANGE
24 Leiden Observatory [Leiden]
25 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
26 Jodrell Bank Centre for Astrophysics
27 UvA - University of Amsterdam [Amsterdam]
28 Ruhr-Universität Bochum [Bochum]
29 Oxford Astrophysics
30 KIT - Karlsruhe Institute of Technology
31 University of Oulu
32 Center for Agricultural Research in Suriname CELOS and Department of Biology
33 Center for Information Technology CIT
34 CRAL - Centre de Recherche Astrophysique de Lyon
35 Interactions Son Musique Mouvement
36 Rhodes University, Grahamstown
37 SKA South Africa
38 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
39 AlfA - Argelander-Institut für Astronomie
40 Kapteyn Astronomical Institute [Groningen]

The low frequency array (LOFAR), is the first radio telescope designed with the capability to measure radio emission from cosmic-ray induced air showers in parallel with interferometric observations. In the first $\sim 2\,\mathrm{years}$ of observing, 405 cosmic-ray events in the energy range of $10^{16} - 10^{18}\,\mathrm{eV}$ have been detected in the band from $30 - 80\,\mathrm{MHz}$. Each of these air showers is registered with up to $\sim1000$ independent antennas resulting in measurements of the radio emission with unprecedented detail. This article describes the dataset, as well as the analysis pipeline, and serves as a reference for future papers based on these data. All steps necessary to achieve a full reconstruction of the electric field at every antenna position are explained, including removal of radio frequency interference, correcting for the antenna response and identification of the pulsed signal.

Keywords: astroparticle physics – methods: data analysis – instrumentation: interferometers

Domains: Sciences of the Universe [physics]

P. Schellart, A. Nelles, S. Buitink, A. Corstanje, J. E. Enriquez, et al.. Detecting cosmic rays with the LOFAR radio telescope. Astronomy and Astrophysics - A&A, 2013, 560 (A98), 14 p. ⟨10.1051/0004-6361/201322683⟩. ⟨insu-01291251⟩