Calibrating the absolute amplitude scale for air showers measured at LOFAR

Nelles A, Horandel JR, Karskens T, Krause M, Buitink S, Corstanje A, Enriquez JE, Erdmann M, Falcke H, Haungs A, Hiller R, Huege T, Krause R, Link K, Norden MJ, Rachen JP, Rossetto L, Schellart P, Scholten O, Schroeder FG, Ter Veen S, Thoudam S, Trinh TNG, Weidenhaupt K, Wijnholds SJ, Anderson J, Baehren L, Bell ME, Bentum MJ, Best P, Bonafede A, Bregman J, Brouw WN, Brueggen M, Butcher HR, Carbone D, Ciardi B, De Gasperin F, Duscha S, Eisloeffel J, Fallows RA, Frieswijk W, Garrett MA, Van Haarlem MP, Heald G, Hoeft M, Horneffer A, Iacobelli M, Juette E, Karastergiou A, Kohler J, Kondratiev VI, Kuniyoshi M, Kuper G, Van Leeuwen J, Maat P, Mcfadden R, Mckay-Bukowski D, Orru E, Paas H, Pandey-Pommier M, Pandey VN, Pizzo R, Polatidis AG, Reich W, Roettgering H, Schwarz D, Serylak M, Sluman J, Smirnov O, Tasse C, Toribio MC, Vermeulen R, Van Weeren RJ, Wijers RAMJ, Wucknitz O, Zarka P (2015)

Publication Status: Published

Publication Type: Journal article

Publication year: 2015

Journal

Publisher: IOP PUBLISHING LTD

Book Volume: 10

Article Number: ARTN P11005

DOI: 10.1088/1748-0221/10/11/P11005

Abstract

Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw-Frequency ARray (LOFAR) and are used to study the properties of cosmic rays. For a complete understanding of this phenomenon and the underlying physical processes, an absolute calibration of the detecting antenna system is needed. We present three approaches that were used to check and improve the antenna model of LOFAR and to provide an absolute calibration of the whole system for air shower measurements. Two methods are based on calibrated reference sources and one on a calibration approach using the diffuse radio emission of the Galaxy, optimized for short data-sets. An accuracy of 19% in amplitude is reached. The absolute calibration is also compared to predictions from air shower simulations. These results are used to set an absolute energy scale for air shower measurements and can be used as a basis for an absolute scale for the measurement of astronomical transients with LOFAR.

Authors with CRIS profile

Involved external institutions

Netherlands Institute for Radio Astronomy Netherlands (NL) Radboud University Nijmegen Netherlands (NL) Universität Hamburg (UHH) Germany (DE) University of Amsterdam Netherlands (NL) Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. (MPG) / Max Planck Society for the Advancement of Science Germany (DE) Australian National University (ANU) Australia (AU) Vrije Universiteit Brussel (VUB) Belgium (BE) University of Edinburgh United Kingdom (GB) Karlsruhe Institute of Technology (KIT) Germany (DE) Australia Telescope National Facility (ATNF) Australia (AU) University of Oxford United Kingdom (GB) University of Groningen / Rijksuniversiteit Groningen Netherlands (NL) Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen Germany (DE) PSL Research University / Université de recherche Paris Sciences et Lettres France (FR) National Astronomical Observatory of Japan / 国立天文台(NAOJ) Japan (JP) Leiden University Netherlands (NL) Rhodes University South Africa (ZA) Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum - GFZ Germany (DE) Ruhr-Universität Bochum (RUB) Germany (DE) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy Germany (DE) Universität Bielefeld Germany (DE) Observatoire de Lyon France (FR) Thüringer Landessternwarte Tautenburg (TLS) - Karl-Schwarzschild-Observatorium Germany (DE) Harvard University United States (USA) (US) Oulun Yliopisto / University of Oulo Finland (FI)

How to cite

APA:

Nelles, A., Horandel, J.R., Karskens, T., Krause, M., Buitink, S., Corstanje, A.,... Zarka, P. (2015). Calibrating the absolute amplitude scale for air showers measured at LOFAR. Journal of Instrumentation, 10. https://dx.doi.org/10.1088/1748-0221/10/11/P11005

MLA:

Nelles, Anna, et al. "Calibrating the absolute amplitude scale for air showers measured at LOFAR." Journal of Instrumentation 10 (2015).

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