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1. Final results of the LOPES radio interferometer for cosmic-ray air showers

Author

W. D. Apel, J. C. Arteaga-Velázquez, L. Bähren, K. Bekk, M. Bertaina, P. L. Biermann, J. Blümer, H. Bozdog, E. Cantoni, A. Chiavassa, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, R. Engel, H. Falcke, B. Fuchs, H. Gemmeke, C. Grupen, A. Haungs, D. Heck, J. R. Hörandel, A. Horneffer, D. Huber, T. Huege, P. G. Isar, K.-H. Kampert, D. Kang, O. Krömer, J. Kuijpers, K. Link, P. Łuczak, M. Ludwig, H. J. Mathes, M. Melissas, C. Morello, S. Nehls, J. Oehlschläger, N. Palmieri, T. Pierog, J. Rautenberg, H. Rebel, M. Roth, C. Rühle, A. Saftoiu, H. Schieler, A. Schmidt, S. Schoo, F.G. Schröder, O. Sima, G. Toma, G. C. Trinchero, A. Weindl, J. Wochele, J. Zabierowski, J. A. Zensus, and LOPES Collaboration

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract LOPES, the LOFAR prototype station, was an antenna array for cosmic-ray air showers operating from 2003 to 2013 within the KASCADE-Grande experiment. Meanwhile, the analysis is finished and the data of air-shower events measured by LOPES are available with open access in the KASCADE Cosmic Ray Data Center (KCDC). This article intends to provide a summary of the achievements, results, and lessons learned from LOPES. By digital, interferometric beamforming the detection of air showers became possible in the radio-loud environment of the Karlsruhe Institute of Technology (KIT). As a prototype experiment, LOPES tested several antenna types, array configurations and calibration techniques, and pioneered analysis methods for the reconstruction of the most important shower parameters, i.e., the arrival direction, the energy, and mass-dependent observables such as the position of the shower maximum. In addition to a review and update of previously published results, we also present new results based on end-to-end simulations including all known instrumental properties. For this, we applied the detector response to radio signals simulated with the CoREAS extension of CORSIKA, and analyzed them in the same way as measured data. Thus, we were able to study the detector performance more accurately than before, including some previously inaccessible features such as the impact of noise on the interferometric cross-correlation beam. These results led to several improvements, which are documented in this paper and can provide useful input for the design of future cosmic-ray experiments based on the digital radio-detection technique.

Published
2021
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2. A comparison of the cosmic-ray energy scales of Tunka-133 and KASCADE-Grande via their radio extensions Tunka-Rex and LOPES

Author

W.D. Apel, J.C. Arteaga-Velázquez, L. Bähren, P.A. Bezyazeekov, K. Bekk, M. Bertaina, P.L. Biermann, J. Blümer, H. Bozdog, I.M. Brancus, N.M. Budnev, E. Cantoni, A. Chiavassa, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, R. Engel, H. Falcke, O. Fedorov, B. Fuchs, H. Gemmeke, O.A. Gress, C. Grupen, A. Haungs, D. Heck, R. Hiller, J.R. Hörandel, A. Horneffer, D. Huber, T. Huege, P.G. Isar, K.-H. Kampert, D. Kang, Y. Kazarina, M. Kleifges, E.E. Korosteleva, D. Kostunin, O. Krömer, J. Kuijpers, L.A. Kuzmichev, K. Link, N. Lubsandorzhiev, P. Łuczak, M. Ludwig, H.J. Mathes, M. Melissas, R.R. Mirgazov, R. Monkhoev, C. Morello, J. Oehlschläger, E.A. Osipova, A. Pakhorukov, N. Palmieri, L. Pankov, T. Pierog, V.V. Prosin, J. Rautenberg, H. Rebel, M. Roth, G.I. Rubtsov, C. Rühle, A. Saftoiu, H. Schieler, A. Schmidt, S. Schoo, F.G. Schröder, O. Sima, G. Toma, G.C. Trinchero, A. Weindl, R. Wischnewski, J. Wochele, J. Zabierowski, A. Zagorodnikov, and J.A. Zensus

Subjects
Physics, QC1-999
Abstract

The radio technique is a promising method for detection of cosmic-ray air showers of energies around 100PeV and higher with an array of radio antennas. Since the amplitude of the radio signal can be measured absolutely and increases with the shower energy, radio measurements can be used to determine the air-shower energy on an absolute scale. We show that calibrated measurements of radio detectors operated in coincidence with host experiments measuring air showers based on other techniques can be used for comparing the energy scales of these host experiments. Using two approaches, first via direct amplitude measurements, and second via comparison of measurements with air shower simulations, we compare the energy scales of the air-shower experiments Tunka-133 and KASCADE-Grande, using their radio extensions, Tunka-Rex and LOPES, respectively. Due to the consistent amplitude calibration for Tunka-Rex and LOPES achieved by using the same reference source, this comparison reaches an accuracy of approximately 10% – limited by some shortcomings of LOPES, which was a prototype experiment for the digital radio technique for air showers. In particular we show that the energy scales of cosmic-ray measurements by the independently calibrated experiments KASCADE-Grande and Tunka-133 are consistent with each other on this level. Keywords: Cosmic rays, Radio detection, LOPES, Tunka-Rex, Tunka-133, KASCADE-Grande

Published
2016
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3. Final results of the LOPES radio interferometer for cosmic-ray air showers

Author

Béatrice Fuchs, W. D. Apel, D. Huber, A. Chiavassa, Heino Falcke, L. Bähren, H. Rebel, J. Blümer, H. J. Mathes, E. Cantoni, P. Łuczak, J. Wochele, Octavian Sima, N. Palmieri, S. Schoo, Frank G. Schröder, J. Rautenberg, C. Rühle, H. Schieler, H. Bozdog, D. Heck, M. Melissas, J. Oehlschläger, K. Bekk, T. Pierog, Karl-Heinz Kampert, Ralph Engel, A. Saftoiu, A. Horneffer, D. Kang, S. Nehls, Markus Roth, C. Grupen, Tim Huege, J. A. Zensus, P. Doll, A. Schmidt, O. Krömer, G. Toma, F. Di Pierro, M. Ludwig, C. Morello, Peter L. Biermann, K. Link, Paula Gina Isar, V. de Souza, A. Haungs, Jörg R. Hörandel, H. Gemmeke, Kai Daumiller, J. Zabierowski, J. C. Arteaga-Velázquez, M. E. Bertaina, G.C. Trinchero, A. Weindl, Jan Kuijpers, and Physics

Subjects
Beamforming, Physics and Astronomy (miscellaneous), Astronomy, FOS: Physical sciences, lcsh:Astrophysics, Cosmic ray, Antenna array, lcsh:QB460-466, ddc:530, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Engineering (miscellaneous), Instrumentation and Methods for Astrophysics (astro-ph.IM), Remote sensing, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, LOPES, Detector, LOFAR, KASCADE, lcsh:QC770-798, Antenna (radio), Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, RAIOS CÓSMICOS, astro-ph.IM
Abstract

LOPES, the LOFAR prototype station, was an antenna array for cosmic-ray air showers operating from 2003 - 2013 within the KASCADE-Grande experiment. Meanwhile, the analysis is finished and the data of air-shower events measured by LOPES are available with open access in the KASCADE Cosmic Ray Data Center (KCDC). This article intends to provide a summary of the achievements, results, and lessons learned from LOPES. By digital, interferometric beamforming the detection of air showers became possible in the radio-loud environment of the Karlsruhe Institute of Technology (KIT). As a prototype experiment, LOPES tested several antenna types, array configurations and calibration techniques, and pioneered analysis methods for the reconstruction of the most important shower parameters, i.e., the arrival direction, the energy, and mass-dependent observables such as the position of the shower maximum. In addition to a review and update of previously published results, we also present new results based on end-to-end simulations including all known instrumental properties. For this, we applied the detector response to radio signals simulated with the CoREAS extension of CORSIKA, and analyzed them in the same way as measured data. Thus, we were able to study the detector performance more accurately than before, including some previously inaccessible features such as the impact of noise on the interferometric cross-correlation beam. These results led to several improvements, which are documented in this paper and can provide useful input for the design of future cosmic-ray experiments based on the digital radio-detection technique., Comment: Accepted for publication by EPJ C

Published
2021

4. Lopes-3D - vectorial measurements of radio emission from cosmic ray induced air showers

Author

J. C. Arteaga-Velázquez, I.M. Brancus, A. Horneffer, T. Pierog, J. Blümer, H. Bozdog, P. Łuczak, N. Palmieri, A. Saftoiu, Andrea Chiavassa, C. Rühle, A. Weindl, Jan Kuijpers, K. Link, K. H. Kampert, A. Haungs, Claus Grupen, Markus Roth, J. A. Zensus, J. Zabierowski, A. Schmidt, O. Krömer, H. J. Mathes, M. E. Bertaina, V. de Souza, Béatrice Fuchs, P. Doll, D. Huber, J. Wochele, G. Toma, J.R. Hörandel, D. Fuhrmann, K. Bekk, H. Rebel, D. Heck, M. Ludwig, W. D. Apel, G. C. Trinchero, Octavian Sima, H. Schieler, Heino Falcke, R. Engel, J. Rautenberg, Kai Daumiller, Frank G. Schröder, D. Kang, L. Bähren, F. Di Pierro, C. Morello, Peter L. Biermann, Paula Gina Isar, H. Gemmeke, M. Melissas, Tim Huege, and J. Oehlschläger

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), LOPES, business.industry, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Measure (physics), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Cosmic ray, Optics, Electric field, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Sensitivity (control systems), business, Astrophysics - High Energy Astrophysical Phenomena
Abstract

LOPES 3D is able to measure all three components of the electric field vector of the radio emission from air showers. This allows a better comparison with emission models. The measurement of the vertical component increases the sensitivity to inclined showers. By measuring all three components of the electric field vector LOPES 3D demonstrates by how much the reconstruction accuracy of primary cosmic ray parameters increases. Thus LOPES 3D evaluates the usefulness of vectorial measurements for large scale applications., Proceedings ARENA 2012

Published
2013

5. Cosmic ray measurements with LOPES: Status and recent results

Author

P. Łuczak, N. Palmieri, O. Krömer, M. Ludwig, Claus Grupen, A. Schmidt, H. Bozdog, M. Melissas, H. Gemmeke, J.R. Hörandel, J. Rautenberg, J. Oehlschläger, Andrea Chiavassa, V. de Souza, J. C. Arteaga-Velázquez, Kai Daumiller, F. Di Pierro, C. Morello, Heino Falcke, H. J. Mathes, A. Weindl, L. Bähren, Jan Kuijpers, C. Rühle, M. E. Bertaina, R. Engel, K. Link, Peter L. Biermann, T. Pierog, A. Haungs, Markus Roth, J. Zabierowski, H. Rebel, Octavian Sima, Béatrice Fuchs, D. Fuhrmann, H. Schieler, J. Wochele, A. Horneffer, D. Kang, D. Heck, K. H. Kampert, Tim Huege, P. Doll, J. Blümer, D. Huber, Frank G. Schröder, Paula Gina Isar, I.M. Brancus, K. Bekk, G. C. Trinchero, G. Toma, A. Saftoiu, W. D. Apel, and J. A. Zensus

Subjects
Physics, Atmosphere, Antenna array, Interferometry, LOPES, Astronomy, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Cosmic ray, Digital radio, Energy (signal processing)
Abstract

LOPES is a digital antenna array at the Karlsruhe Institute of Technology, Germany, for cosmic-ray air-shower measurements. Triggered by the co-located KASCADE-Grande air-shower array, LOPES detects the radio emission of air showers via digital radio interferometry. We summarize the status of LOPES and recent results. In particular, we present an update on the reconstruction of the primary-particle properties based on almost 500 events above 100PeV. With LOPES, the arrival direction can be reconstructed with a precision of at least 0.65°, and the energy with a precision of at least 20%, which, however, does not include systematic uncertainties on the absolute energy scale. For many particle and astrophysics questions the reconstruction of the atmospheric depth of the shower maximum, Xmax, is important, since it yields information on the type of the primary particle and its interaction with the atmosphere. Recently, we found experimental evidence that the slope of the radio lateral distribution is indeed s...

Published
2013

6. Revised absolute amplitude calibration of the LOPES experiment

Author

M. Melissas, J. Oehlschläger, H. Bozdog, R. Hiller, C. Rühle, O. Krömer, Heino Falcke, H. Rebel, Markus Roth, H. Gemmeke, A. Chiavassa, N. Palmieri, K. Bekk, P. Doll, V. de Souza, J. Rautenberg, A. Horneffer, E. Cantoni, S. Schoo, Katrin Link, D. Kang, Ralph Engel, Andreas Haungs, A. Weindl, T. Pierog, Jan Kuijpers, L. Bähren, M. Ludwig, A. Schmidt, F. Di Pierro, C. Morello, Tim Huege, J. Wochele, Octavian Sima, D. Heck, M. E. Bertaina, J. Zabierowski, Kai Daumiller, D. Huber, Claus Grupen, Béatrice Fuchs, A. Saftoiu, G. Toma, and H. Schieler

Subjects
Physics, Amplitude, Optics, LOPES, business.industry, Monte Carlo method, Calibration, Cosmic ray, business, Signal, Energy (signal processing), Radio wave, Computational physics
Abstract

One of the main aims of the LOPES experiment was the evaluation of the absolute amplitudeof the radio signal of air showers. This is of special interest since the radio technique offers the pos-sibility for an independent and highly precise determination of the energy scale of cosmic rays onthe basis of signal predictions from Monte Carlo simulations. For the calibration of the amplitudemeasured by LOPES we used an external source. Previous comparisons of LOPES measurementsand simulations of the radio signal amplitude predicted by CoREAS revealed a discrepancy of theorder of a factor of two. A re-measurement of the reference calibration source, now performed forthe free field, was recently performed by the manufacturer. The updated calibration values leadto a lowering of the reconstructed electric field measured by LOPES by a factor of 2:6 0:2 andtherefore to a significantly better agreement with CoREAS simulations. We discuss the updatedcalibration and its impact on the LOPES analysis results.2

Published
2016

7. A comparison of the cosmic-ray energy scales of Tunka-133 and KASCADE-Grande via their radio extensions Tunka-Rex and LOPES

Author

R. D. Monkhoev, Harald Schieler, Hermann-Josef Mathes, J.C. Arteaga-Velázquez, Kai Daumiller, V. V. Prosin, Alexandra Saftoiu, C. Grupen, A. Chiavassa, N. B. Lubsandorzhiev, I.M. Brancus, J. Zabierowski, G. Toma, P. Łuczak, N. Palmieri, M. E. Bertaina, R. Wischnewski, Jan Kuijpers, E. E. Korosteleva, J. Blümer, Andreas Weindl, J. Wochele, Dmitriy Kostunin, O. A. Gress, G.C. Trinchero, Octavian Sima, Julian Rautenberg, M. Kleifges, F. Di Pierro, W. D. Apel, Katrin Link, Tanguy Pierog, C. Rühle, Grigory Rubtsov, J. A. Zensus, H. Bozdog, E. A. Osipova, O. Krömer, M. Melissas, A. Schmidt, Yulia Kazarina, Pavel Bezyazeekov, A. L. Pakhorukov, R. Hiller, Markus Roth, Ralph Engel, Tim Huege, Jörg R. Hörandel, J. Oehlschläger, C. Morello, Andreas Haungs, H. Rebel, Peter L. Biermann, Paula Gina Isar, D. Huber, P. Doll, B. Fuchs, A. Horneffer, L. V. Pankov, L. Bähren, D. Kang, R. R. Mirgazov, M. Ludwig, Oleg Fedorov, S. Schoo, Karl-Heinz Kampert, Dieter Heck, V. de Souza, Heino Falcke, E. Cantoni, A. V. Zagorodnikov, F. G. Schröder, L. A. Kuzmichev, K. Bekk, H. Gemmeke, and N. M. Budnev

Subjects
Nuclear and High Energy Physics, Cosmic rays, KASCADE-Grande, LOPES, Radio detection, Tunka-133, Tunka-Rex, Physics::Instrumentation and Detectors, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, 01 natural sciences, Air showers, 0103 physical sciences, ddc:530, 010306 general physics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Digital radio, ASTROFÍSICA, lcsh:QC1-999, Computational physics, Air shower, Amplitude, KASCADE, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, lcsh:Physics, Radio wave
Abstract

Physics letters / B 763, 179 - 185(2016). doi:10.1016/j.physletb.2016.10.031, The radio technique is a promising method for detection of cosmic-ray air showers of energies around View the MathML source100PeV and higher with an array of radio antennas. Since the amplitude of the radio signal can be measured absolutely and increases with the shower energy, radio measurements can be used to determine the air-shower energy on an absolute scale. We show that calibrated measurements of radio detectors operated in coincidence with host experiments measuring air showers based on other techniques can be used for comparing the energy scales of these host experiments. Using two approaches, first via direct amplitude measurements, and second via comparison of measurements with air shower simulations, we compare the energy scales of the air-shower experiments Tunka-133 and KASCADE-Grande, using their radio extensions, Tunka-Rex and LOPES, respectively. Due to the consistent amplitude calibration for Tunka-Rex and LOPES achieved by using the same reference source, this comparison reaches an accuracy of approximately 10%10% – limited by some shortcomings of LOPES, which was a prototype experiment for the digital radio technique for air showers. In particular we show that the energy scales of cosmic-ray measurements by the independently calibrated experiments KASCADE-Grande and Tunka-133 are consistent with each other on this level., Published by North-Holland Publ., Amsterdam

Published
2016

8. New measurements of cosmic ray air showers with the digital radio interferometer LOPES

Author

P. Łuczak, H. Gemmeke, N. Palmieri, M. Finger, Claus Grupen, A. Chiavassa, J. Wochele, Octavian Sima, M. Ludwig, D. Kang, D. Heck, H. Bozdog, S.J. Lafebre, Heino Falcke, J. Blümer, H. J. Mathes, Tim Huege, L. Bähren, A. Weindl, F.G. Schröder, O. Krömer, Jan Kuijpers, D. Huber, J. A. Zensus, E. Cantoni, Ralph Engel, M. Wommer, Alexandra Saftoiu, J.C. Arteaga, A. Schmidt, A. Horneffer, K. Bekk, C. Rühle, C. Morello, T. Asch, D. Fuhrmann, W. D. Apel, Peter L. Biermann, Markus Roth, J. Rautenberg, Peter Buchholz, G. Toma, T. Pierog, I.M. Brancus, S. Nehls, Kai Daumiller, V. de Souza, Jörg R. Hörandel, P.G. Isar, G.C. Trinchero, J. Oehlschläger, M. E. Bertaina, Stijn Buitink, K. Link, A. Haungs, H. Rebel, J. Zabierowski, H. Schieler, M. Melissas, P. Doll, and K. H. Kampert

Subjects
Physics, Physics and Astronomy (miscellaneous), LOPES, Frequency band, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Cosmic ray, Aetiology, screening and detection [ONCOL 5], Astrophysics::Cosmology and Extragalactic Astrophysics, Digital radio, law.invention, Radio telescope, Interferometry, Air shower, law, RÁDIO, Dipole antenna, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

LOPES is a digital radio interferometer which measures the radio emission of extensive cosmic ray air showers. It mainly consists of 30 dipole antennas installed in co-location with KASCADE-Grande at the Karlsruhe Insti- tute of Technology (KIT) in Germany. KASCADE-Grande measures the secondary air shower particles at ground. Whenever KASCADE-Grande detects a high-energy cosmic ray event (� 10 16 eV), it triggers LOPES which then digi- tally records the radio signal in the frequency band from 40 to 80 MHz. Using interferometric methods, LOPES is able to successfully detect air shower induced radio pulses, even in the noisy environment at the KIT. In the present studies, a considerable progress in understanding the radio emission mechanism is shown: The latest version of the "radio emis

Published
2011

9. An air shower array for LOFAR: LORA

Author

Arthur Corstanje, Heino Falcke, L. Bähren, C. W. James, Jörg R. Hörandel, M. Mevius, Martin van den Akker, K. Singh, Satyendra Thoudam, S. ter Veen, Olaf Scholten, Guus van Aar, A. Horneffer, KVI - Center for Advanced Radiation Technology, and Research unit Nuclear & Hadron Physics

Subjects
Physics, Physics and Astronomy (miscellaneous), Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, LOFAR, Radio telescope, Air shower, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Small particles, Neutrino, Detector array, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Radio detection
Abstract

LOFAR is a new form of radio telescope which can detect radio emission from air showers induced by very high-energy cosmic rays. It can also look for radio emission from particle cascades on the Moon induced by ultra high-energy cosmic rays or neutrinos. To complement the radio detection, we are setting up a small particle detector array LORA (LOfar Radboud Air shower array) within an area of $\sim 300$ m diameter in the LOFAR core. It will help in triggering and confirming the radio detection of air showers with the LOFAR antennas. In this paper, we present a short overview about LORA and discuss its current status., Comment: 10 pages (using article.cls), 6 figures, accepted for the proceedings of 22nd European Cosmic Ray Symposium, 3-6 August 2010, Finland

Published
2011

10. New method for the time calibration of an interferometric radio antenna array

Author

A. Horneffer, L. Bähren, O. Krömer, H. Bozdog, Tim Huege, A. Haungs, J. Blümer, P.G. Isar, Heino Falcke, S. Nehls, T. Asch, and F.G. Schröder

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nuclear and High Energy Physics, LOPES, Directional antenna, business.industry, Reflective array antenna, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, LOFAR, law.invention, Optics, law, Reference antenna, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Dipole antenna, Antenna (radio), business, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation, Instrumentation and Methods for Astrophysics (astro-ph.IM), Radio wave
Abstract

Digital radio antenna arrays, like LOPES (LOFAR PrototypE Station), detect high-energy cosmic rays via the radio emission from atmospheric extensive air showers. LOPES is an array of dipole antennas placed within and triggered by the KASCADE-Grande experiment on site of the Karlsruhe Institute of Technology, Germany. The antennas are digitally combined to build a radio interferometer by forming a beam into the air shower arrival direction which allows measurements even at low signal-to-noise ratios in individual antennas. This technique requires a precise time calibration. A combination of several calibration steps is used to achieve the necessary timing accuracy of about 1 ns. The group delays of the setup are measured, the frequency dependence of these delays (dispersion) is corrected in the subsequent data analysis, and variations of the delays with time are monitored. We use a transmitting reference antenna, a beacon, which continuously emits sine waves at known frequencies. Variations of the relative delays between the antennas can be detected and corrected for at each recorded event by measuring the phases at the beacon frequencies., 9 pages, 9 figures, 1 table, pre-print of article published in Nuclear Inst. and Methods in Physics Research, A, available at: http://www.sciencedirect.com/science/article/B6TJM-4Y9CF4B-4/2/37bfcb899a0f387d9875a5a0729593ae

Published
2010

11. Recent results of the LOPES experiment

Author

K. Link, A. Haungs, H. Rebel, G. Toma, H. Bozdog, M. Wommer, H. Gemmeke, T. Huege, B. Mitrica, Heino Falcke, F. Cossavella, F. Di Pierro, J. Zabierowski, C. Morello, D. Kickelbick, M. Ludwig, A. Nigl, Wolfgang Walkowiak, Peter L. Biermann, A. Saftoiu, P. Łuczak, N. Palmieri, V. de Souza, M. Finger, G. Navarra, W. D. Apel, K. Singh, Jörg R. Hörandel, Frank G. Schröder, T. Asch, J. A. Zensus, J.C. Arteaga, J. Wochele, M. Melissas, R. Engel, E. Cantoni, Octavian Sima, J. Oehlschläger, A. Horneffer, D. Kang, Peter Buchholz, O. Krömer, S. Over, J. Blümer, I.M. Brancus, D. Fuhrmann, H. Schieler, D. Heck, Karl-Heinz Kampert, Markus Roth, L. Bähren, T. Pierog, Y. Kolotaev, M. Brüggemann, H. Ulrich, Piera Luisa Ghia, S. Nehls, G.C. Trinchero, H. J. Mathes, M. Petcu, P. Doll, Paula Gina Isar, A. Schmidt, R. Glasstetter, J. Rautenberg, Kai Daumiller, M. E. Bertaina, Stijn Buitink, H.J. Mayer, Andrea Chiavassa, C. Grupen, Moses Ender, A. Weindl, Jan Kuijpers, S.J. Lafebre, F. Badea, and K. Bekk

Subjects
Physics, Nuclear and High Energy Physics, Data processing, Interferometry, Air shower, Meteorology, LOPES, Digital radio, Signal, Atomic and Molecular Physics, and Optics, Remote sensing
Abstract

LOPES measures radio pulses from extensive air showers and aims to calibrate the emitted signal in the primary energy range of 1016–1018 eV. LOPES, a digital radio interferometer using high bandwidths and fast data processing, is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and profits from the reconstructed air shower observables of KASCADE-Grande. We report about recent analysis results of the radio signals measured by LOPES.

Published
2009

12. Air shower measurements with LOFAR

Author

Olaf Scholten, Jörg R. Hörandel, A. Nigl, A. Horneffer, Heino Falcke, L. Bähren, Jan Kuijpers, S.J. Lafebre, K. Singh, Stijn Buitink, and KVI - Center for Advanced Radiation Technology

Subjects
Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, Scintillator, Electromagnetic interference, Radio telescope, Optics, Instrumentation, Instrumentation and Methods for Astrophysics (astro-ph.IM), Cosmic rays, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, LOFAR, Pulse (physics), Air shower, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, business, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Air showers from cosmic rays emit short, intense radio pulses. LOFAR is a new radio telescope, that is being built in the Netherlands and Europe. Designed primarily as a radio interferometer, the core of LOFAR will have a high density of radio antennas, which will be extremely well calibrated. This makes LOFAR a unique tool for the study of the radio properties of single air showers. Triggering on the radio emission from air showers means detecting a short radio pulse and discriminating real events from radio interference. At LOFAR we plan to search for pulses in the digital data stream - either from single antennas or from already beam-formed data - and calculate several parameters characterizing the pulse shape to pick out real events in a second stage. In addition, we will have a small scintillator array to test and confirm the performance of the radio only trigger., Comment: Proceedings of the ARENA 2008 workshop, to be published in NIM A

Published
2009

13. Analysis of inclined showers measured with LOPES

Author

A. Saftoiu, W.D. Apel, J.C. Arteaga, T. Asch, J. Auffenberg, F. Badea, L. Bähren, K. Bekk, M. Bertaina, P.L. Biermann, J. Blümer, H. Bozdog, I.M. Brancus, M. Brüggemann, P. Buchholz, S. Buitink, E. Cantoni, A. Chiavassa, F. Cossavella, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, R. Engel, H. Falcke, M. Finger, D. Fuhrmann, H. Gemmeke, P.L. Ghia, R. Glasstetter, C. Grupen, A. Haungs, D. Heck, J.R. Hörandel, A. Horneffer, T. Huege, P.G. Isar, K.-H. Kampert, D. Kang, D. Kickelbick, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, P. Łuczak, H.J. Mathes, H.J. Mayer, J. Milke, B. Mitrica, C. Morello, G. Navarra, S. Nehls, A. Nigl, J. Oehlschläger, S. Over, M. Petcu, T. Pierog, J. Rautenberg, H. Rebel, M. Roth, H. Schieler, A. Schmidt, F. Schröder, O. Sima, K. Singh, M. Stümpert, G. Toma, G.C. Trinchero, H. Ulrich, W. Walkowiak, A. Weindl, J. Wochele, M. Wommer, J. Zabierowski, and J.A. Zensus

Subjects
Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Amplitude, Air shower, Optics, Earth's magnetic field, KASCADE, Antenna (radio), business, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Instrumentation
Abstract

In the present study, we analyze the radio signal from inclined air showers recorded by LOPES-30 in coincidence with KASCADE-Grande. LOPES-30 consists of 30 East–West oriented digital antennas, which are amplitude calibrated by an external source. Radio emission from air showers is considered a geomagnetic effect. Inclined events provide a larger range of values for geomagnetic angle (angle between shower axis and geomagnetic field direction) than vertical showers and thus more information on the emission processes can be gathered. In order to have the geometry of the air shower we use the reconstruction provided by the KASCADE-Grande particle detectors array. Analyzing events observed by both LOPES and the extended part of the KASCADE array, Grande, gives the possibility to test in particular the capability and efficiency of radio detection of more distant events. The results are compared with a previous analysis of inclined events recorded by the initial 10 antenna set-up, LOPES-10, in coincidence with the Grande array.

Published
2009

14. Recent Results from KASCADE-Grande and LOPES

Author

K.-H. Kampert, W.D. Apel, J.C. Arteaga, T. Asch, F. Badea, L. Bähren, K. Bekk, M. Bertaina, P.L. Biermann, J. Blümer, H. Bozdog, I.M. Brancus, M. Brüggemann, P. Buchholz, S. Buitink, E. Cantoni, A. Chiavassa, F. Cossavella, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, M. Ender, R. Engel, J. Engler, H. Falcke, M. Finger, D. Fuhrmann, H. Gemmeke, P.L. Ghia, H.J. Gils, R. Glasstetter, C. Grupen, A. Haungs, D. Heck, J.R. Hörandel, A. Horneffer, T. Huege, P.G. Isar, D. Kang, D. Kickelbick, H.O. Klages, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, K. Link, P. Łuczak, M. Ludwig, H.J. Mathes, H.J. Mayer, J. Milke, M. Melissas, B. Mitrica, C. Morello, G. Navarra, S. Nehls, A. Nigl, J. Oehlschläger, S. Ostapchenko, S. Over, N. Palmieri, M. Petcu, T. Pierog, J. Rautenberg, H. Rebel, M. Roth, A. Saftoiu, H. Schieler, A. Schmidt, F. Schröder, O. Sima, K. Singh, M. Stümpert, G. Toma, G. Trinchero, H. Ulrich, W. Walkowiak, A. Weindl, J. Wochele, M. Wommer, J. Zabierowski, and J.A. Zensus

Subjects
Physics, Nuclear and High Energy Physics, Muon, LOPES, business.industry, Detector, Electrical engineering, Cosmic ray, Tracking (particle physics), Signal, Atomic and Molecular Physics, and Optics, Computational physics, KASCADE, business, Energy (signal processing)
Abstract

KASCADE-Grande is an extensive air-shower experiment located at Forschungszentrum Karlsruhe, Germany. Main parts of the experiment are the Grande array spread over an area of 700 × 700 m 2 , the original KASCADE array covering 200 × 200 m 2 with unshielded and shielded detectors, and additional muon tracking devices. This multi-detector system allows to investigate the energy spectrum, composition, and anisotropies of cosmic rays in the energy range up to 1 EeV. LOPES is co-located at the same site to measure radio pulses from extensive air showers in coincidence with KASCADE-Grande. It consists of 30 digital antennas operated in different geometrical configurations. Read out is performed at high bandwidths and rate data processing with the aim to calibrate the emitted signal in the primary energy range of 10 16 − 10 18 eV by making use of reconstructed air-shower observables of KASCADE-Grande. An overview on the performance of both experiments will be given and recent analysis results be reported.

Published
2009

15. Air shower measurements with the LOPES radio antenna array

Author

A. Haungs, W.D. Apel, J.C. Arteaga, T. Asch, J. Auffenberg, F. Badea, L. Bähren, K. Bekk, M. Bertaina, P.L. Biermann, J. Blümer, H. Bozdog, I.M. Brancus, M. Brüggemann, P. Buchholz, S. Buitink, E. Cantoni, A. Chiavassa, F. Cossavella, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, R. Engel, H. Falcke, M. Finger, D. Fuhrmann, H. Gemmeke, P.L. Ghia, R. Glasstetter, C. Grupen, D. Heck, J.R. Hörandel, A. Horneffer, T. Huege, P.G. Isar, K.-H. Kampert, D. Kang, D. Kickelbick, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, P. Łuczak, H.J. Mathes, H.J. Mayer, J. Milke, B. Mitrica, C. Morello, G. Navarra, S. Nehls, A. Nigl, J. Oehlschläger, S. Over, M. Petcu, T. Pierog, J. Rautenberg, H. Rebel, M. Roth, A. Saftoiu, H. Schieler, A. Schmidt, F. Schröder, O. Sima, K. Singh, M. Stümpert, G. Toma, G.C. Trinchero, H. Ulrich, W. Walkowiak, A. Weindl, J. Wochele, M. Wommer, J. Zabierowski, and J.A. Zensus

Subjects
Pierre Auger Observatory, Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics, Digital radio, Antenna array, Interferometry, Air shower, Optics, Amplitude, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, business, Instrumentation, Radio wave
Abstract

LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. Since radio waves suffer very little attenuation, radio measurements allow the detection of very distant or highly inclined showers. These waves can be recorded day and night, and provide a bolometric measure of the leptonic shower component. LOPES is designed as a digital radio interferometer using high bandwidths and fast data processing and profits from the reconstructed air shower observables of KASCADE-Grande. The LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the electric field strength which can be compared with predictions from detailed Monte Carlo simulations. We report about the analysis of correlations present in the radio signals measured by the LOPES 30 antenna array. Additionally, LOPES operates antennas of a different type (LOPES-STAR) which are optimized for an application at the Pierre Auger Observatory. Status, recent results of the data analysis and further perspectives of LOPES and the possible large scale application of this new detection technique are discussed., Comment: 8 pages, 10 figures, Contribution to the Arena 2008 conference, Rome, June 2008

Published
2009

16. Radio detection of cosmic ray air showers with LOPES

Author

T. Huege, W.D. Apel, T. Asch, A.F. Badea, L. Bähren, K. Bekk, A. Bercuci, M. Bertaina, P.L. Biermann, J. Blümer, H. Bozdog, I.M. Brancus, S. Buitink, M. Brüggemann, P. Buchholz, H. Butcher, A. Chiavassa, F. Cossavella, K. Daumiller, F. Di Pierro, P. Doll, R. Engel, H. Falcke, H. Gemmeke, P.L. Ghia, R. Glasstetter, C. Grupen, A. Hakenjos, A. Haungs, D. Heck, J.R. Hörandel, A. Horneffer, P.G. Isar, K.H. Kampert, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, H.J. Mathes, H.J. Mayer, C. Meurer, J. Milke, B. Mitrica, C. Morello, G. Navarra, S. Nehls, A. Nigl, R. Obenland, J. Oehlschläger, S. Ostapchenko, S. Over, M. Petcu, J. Petrovic, T. Pierog, S. Plewnia, H. Rebel, A. Risse, M. Roth, H. Schieler, O. Sima, K. Singh, M. Stümpert, G. Toma, G.C. Trinchero, H. Ulrich, J. van Buren, W. Walkowiak, A. Weindl, J. Wochele, J. Zabierowski, J.A. Zensus, and D. Zimmermann

Subjects
Physics, Pierre Auger Observatory, Nuclear and High Energy Physics, LOPES, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, The Renaissance, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Atomic and Molecular Physics, and Optics, Earth's magnetic field, Radio detection
Abstract

In the last few years, radio detection of cosmic ray air showers has experienced a true renaissance, becoming manifest in a number of new experiments and simulation efforts. In particular, the LOPES project has successfully implemented modern interferometric methods to measure the radio emission from extensive air showers. LOPES has confirmed that the emission is coherent and of geomagnetic origin, as expected by the geosynchrotron mechanism, and has demonstrated that a large scale application of the radio technique has great potential to complement current measurements of ultra-high energy cosmic rays. We describe the current status, most recent results and open questions regarding radio detection of cosmic rays and give an overview of ongoing research and development for an application of the radio technique in the framework of the Pierre Auger Observatory., 8 pages; Proceedings of the CRIS2006 conference, Catania, Italy; to be published in Nuclear Physics B, Proceedings Supplements

Published
2007

17. Radio emission of highly inclined cosmic ray air showers measured with LOPES

Author

J. Petrovic, W. D. Apel, T. Asch, F. Badea, L. Bähren, K. Bekk, A. Bercuci, M. Bertaina, P. L. Biermann, J. Blümer, H. Bozdog, I. M. Brancus, M. Brüggemann, P. Buchholz, S. Buitink, H. Butcher, A. Chiavassa, F. Cossavella, K. Daumiller, F. Di Pierro, P. Doll, R. Engel, H. Falcke, H. Gemmeke, P. L. Ghia, R. Glasstetter, C. Grupen, A. Haungs, D. Heck, J. R. Hörandel, A. Horneffer, T. Huege, K.-H. Kampert, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, H. J. Mathes, H. J. Mayer, C. Meurer, J. Milke, B. Mitrica, C. Morello, G. Navarra, S. Nehls, A. Nigl, R. Obenland, J. Oehlschläger, S. Ostapchenko, S. Over, M. Petcu, T. Pierog, S. Plewnia, H. Rebel, A. Risse, M. Roth, H. Schieler, O. Sima, K. Singh, M. Stümpert, G. Toma, G. C. Trinchero, H. Ulrich, J. van Buren, W. Walkowiak, A. Weindl, J. Wochele, J. Zabierowski, J. A. Zensus, and D. Zimmermann

Subjects
Physics, LOPES, Physics::Instrumentation and Detectors, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Detector, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, LOFAR, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Air shower, KASCADE, Space and Planetary Science, High Energy Physics::Experiment, Event (particle physics), Zenith
Abstract

Contains fulltext : 36387.pdf ( ) (Open Access) Contains fulltext : 36387.pdf (Publisher’s version ) (Open Access) Aims.The capability of radio antenna arrays to measure cosmic ray air showers with very large zenith angles is explored. This is important, since a possible neutrino detection has to fulfill two requirements. First: antennas should be able to detect very inclined cosmic ray air showers, and second: it should be possible to estimate the distance to the shower maximum, since neutrinos are most likely to travel far through the Earth's atmosphere without interaction and induce air showers close to the ground. Methods: LOPES (LOFAR PrototypE Station; LOFAR - LOw Frequency ARray), an array of dipole antennas, is used for the detection of inclined cosmic ray air showers. LOPES is co-located and triggered by the KASCADE (KArlsruhe Shower Core and Array DEtector) experiment, which also provides information on air shower properties such as electron and muon numbers on the ground, as well as the arrival direction. Radio emission of nearly vertical cosmic ray air showers has been detected by LOPES. Results: LOPES-10 (the first phase of LOPES, consisting of 10 antennas) detected a significant number of cosmic ray air showers with a zenith angle larger than 50°, and many of these have very high radio field strengths. The most inclined event that has been detected with LOPES-10 has a zenith angle of almost 80°. This is proof that the new technique is also applicable for cosmic ray air showers with high inclinations, which in the case that they are initiated close to the ground, can be a signature of neutrino events. Conclusions: .Our results indicate that arrays of simple radio antennas can be used for the detection of highly inclined air showers, which might be triggered by neutrinos. In addition, we found that the radio pulse height (normalized with the muon number) for highly inclined events increases with the geomagnetic angle, which confirms the geomagnetic origin of radio emission in cosmic ray air showers.

Published
2007

18. LOPES — Recent Results and Open Questions on the Radio Detection of Air Showers

Author

M. Melissas, A. Horneffer, J. C. Arteaga-Velázquez, J. Oehlschläger, D. Kang, K. Link, G.C. Trinchero, Heino Falcke, A. Schmidt, A. Haungs, J. Zabierowski, Kai Daumiller, V. de Souza, H. Rebel, E. Cantoni, D. Huber, A. Weindl, J. Wochele, A. Saftoiu, S. Schoo, T. Pierog, Jan Kuijpers, Octavian Sima, Jörg R. Hörandel, H. Schieler, J. A. Zensus, D. Heck, M. E. Bertaina, Ralph Engel, P. Doll, H. J. Mathes, K. Bekk, F.G. Schröder, H. Gemmeke, L. Bähren, I.M. Brancus, Béatrice Fuchs, G. Toma, M. Ludwig, J. Rautenberg, C. Morello, F. Di Pierro, H. Bozdog, K. H. Kampert, C. Rühle, W. D. Apel, Peter L. Biermann, J. Blümer, Markus Roth, C. Grupen, A. Chiavassa, O. Krömer, Paula Gina Isar, Tim Huege, P. Łuczak, and N. Palmieri

Subjects
Beamforming, Wavefront, Physics, History, LOPES, business.industry, Astronomy, Computer Science Applications, Education, Antenna array, Interferometry, Optics, Amplitude, Antenna (radio), business, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Energy (signal processing)
Abstract

LOPES was a digital antenna array operating for approximately 10 years until spring 2013 at the Karlsruhe Institute of Technology (KIT). Triggered by the co-located KASCADE-Grande air-shower experiment, it measured the radio signal of around 1000 cosmic-ray air showers with energies E ≳ 1017 eV in an effective band of 43 - 74 MHz. Using the interferometric technique of cross-correlation beamforming, LOPES could reconstruct the shower direction with an accuracy < 0.7°, the shower energy with a precision < 20%, and the atmospheric depth of the shower maximum, Xmax, with a precision < 95g/cm2. In particular the reconstruction of the shower maximum suffers from significant measurement uncertainties due to the radio-loud environment of the site. This article summarizes our latest results on the reconstruction of the shower maximum, using two independent methods: the steepness of the hyperbolic radio wavefront and the slope of the lateral distribution of the radio amplitude. Moreover, we show vectorial measurements of the electric field with the tripole antennas of the latest LOPES setup. Finally, we discuss open questions as well as the potential impact of the lessons learned at LOPES for future antenna arrays.

Published
2015

19. Calibrating the absolute amplitude scale for air showers measured at LOFAR

Author

A. Haungs, Stijn Buitink, A. Nelles, Olaf Scholten, Oleg Smirnov, Pim Schellart, George Heald, Jörg P. Rachen, Jörg R. Hörandel, Maria Krause, A. G. Polatidis, Emanuela Orrú, Wilfred Frieswijk, H. J. A. Röttgering, W. N. Brouw, Rebecca McFadden, Frank G. Schröder, J. Kohler, Katrin Link, R. Krause, P. Zarka, M. Iacobelli, J. Sluman, P. N. Best, P. Maat, M. J. Norden, Roberto Pizzo, Satyendra Thoudam, K. Weidenhaupt, M. P. van Haarlem, M. C. Toribio, Gerard H. Kuper, J. E. Enriquez, A. Horneffer, T. Karskens, Harvey Butcher, F. de Gasperin, J. D. Bregman, S. ter Veen, R. C. Vermeulen, Jochen Eislöffel, Heino Falcke, V. I. Kondratiev, M. Pandey-Pommier, H. Paas, E. Juette, M. Bruüggen, R. Hiller, W. Reich, James M. Anderson, Stefan J. Wijnholds, R. J. van Weeren, Arthur Corstanje, A. Karastergiou, B. Ciardi, Matthias Hoeft, D. McKay-Bukowski, Laura Rossetto, O. Wucknitz, T. N. G. Trinh, S. Duscha, C. Tasse, Martin Bell, M. Serylak, Mark J. Bentum, Tim Huege, J. van Leeuwen, M. Kuniyoshi, Vishambhar Pandey, D. Carbone, Ralph A. M. J. Wijers, Dominik J. Schwarz, Richard Fallows, M. A. Garrett, L. Bähren, Martin Erdmann, Annalisa Bonafede, Physics, Astronomy and Astrophysics Research Group, Elementary Particle Physics, Radboud university [Nijmegen], Institut de Génomique Fonctionnelle de Lyon (IGFL), École normale supérieure - Lyon (ENS Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Karlsruher Institut für Technologie - Campus Nord, Karlsruher Institut für Technologie - Campus Süd, Netherlands Institute for Radio Astronomy (ASTRON), Department of Astrophysics [Nijmegen], Radboud university [Nijmegen]-Radboud university [Nijmegen], University of Groningen [Groningen], Global Aerospace, Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Jacobs University [Bremen], Kapteyn Astronomical Institute [Groningen], Research School of Astronomy and Astrophysics [Canberra] (RSAA), Australian National University (ANU), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Hamburger Sternwarte/Hamburg Observatory, Universität Hamburg (UHH), Thüringer Landessternwarte Tautenburg (TLS), Adran Ffiseg, Prifysgol Cymru Aberystwyth, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Joint Institute for VLBI in Europe (JIVE ERIC), DPMMS/CMS, University of Cambridge [UK] (CAM), Ruhr-Universität Bochum [Bochum], Oxford Astrophysics, University of Oxford [Oxford], Karlsruhe Institute of Technology (KIT), Max-Planck-Institut für Radioastronomie (MPIFR), University of Oulu, University of Groningen, Groningen, Netherlands, Centre de Recherche Astrophysique de Lyon (CRAL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Department of Physics and Astronomy [South Africa], University of the Western Cape, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Aucun, Stichting WBBS, Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Lyon (ENS Lyon), Department of Pure Mathematics and Mathematical Statistics (DPMMS), Faculty of mathematics Centre for Mathematical Sciences [Cambridge] (CMS), University of Cambridge [UK] (CAM)-University of Cambridge [UK] (CAM), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Radboud University [Nijmegen], École normale supérieure de Lyon (ENS de Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Radboud University [Nijmegen]-Radboud University [Nijmegen], Universiteit Leiden, University of Oxford, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of the Western Cape (UWC), High Energy Astrophys. & Astropart. Phys (API, FNWI), Research unit Astroparticle Physics, Astronomy, and Kapteyn Astronomical Institute

Subjects
Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Optics, Calibration, ddc:610, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instrumentation, Absolute scale, ComputingMilieux_MISCELLANEOUS, Mathematical Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [PHYS]Physics [physics], Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, LOFAR, Amplitude, Air shower, Experimental High Energy Physics, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Antennas, Radio frequency, Antenna (radio), Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], business
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., Comment: 34 pages, 10 figures

Published
2015

20. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

Author

Casey J. Law, M. Kuniyoshi, Tim D. Staley, M. Pietka, S. Cooper, Michael Kramer, Charlotte Sobey, Patrick Weltevrede, B. Scheers, S. Marko, P.G. Jonker, A. Alexov, P. Zarka, Heino Falcke, E. Rol, Aris Karastergiou, T. E. Hassall, Adam Stewart, Michael W. Wise, Rudy Wijnands, M. Pilia, James Miller-Jones, Martin Bell, Evan Keane, Jason W. T. Hessels, J. Masters, J.-M. Grießmeier, L. Bähren, Jochen Eislöffel, Antonia Rowlinson, T. Coenen, Hugh Garsden, Stefan Oslowski, J. van Leeuwen, B. W. Stappers, Rob Fender, Y. Cendes, K. Zagkouris, Anna V. Bilous, R. A. Osten, V. I. Kondratiev, John D. Swinbank, Ralph A. M. J. Wijers, Joris P. W. Verbiest, D. Carbone, S. ter Veen, A. J. van der Horst, M. Serylak, H. Spreeuw, Gijs Molenaar, Rene P. Breton, J. W. Broderick, Stephane Corbel, A. Noutsos, Kenneth C. Anderson, Netherlands Institute for Radio Astronomy (ASTRON), Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], Max-Planck-Institut für Radioastronomie (MPIFR), Universität Bielefeld, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], School of Mathematics [Cardiff], Cardiff University, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), School of Physics and Astronomy [Southampton], University of Southampton, Centre for Astrophysics and Supercomputing, Swinburne University of Technology [Melbourne], Sub-department of Astrophysics [Oxford], Department of Physics [Oxford], University of Oxford [Oxford]-University of Oxford [Oxford], Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Thüringer Landessternwarte Tautenburg (TLS), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Department of Astrophysical Sciences [Princeton], Princeton University, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Database Architectures, Radboud University [Nijmegen], Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), University of Oxford-University of Oxford, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), High Energy Astrophys. & Astropart. Phys (API, FNWI), Jodrell Bank Centre for Astrophysics, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Magnetosphere, Astrophysics, polarisation, low frequencies, Spectral line, symbols.namesake, Pulsar, Millisecond pulsar, pulsars: general, Faraday effect, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, instrumentation, polarization, Scattering, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], scattering, Astronomy and Astrophysics, LOFAR, radiation mechanisms: non-thermal, Astrophysics - Astrophysics of Galaxies, Interstellar medium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, symbols, pulsars, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from the propagation of polarised emission in the pulsar magnetosphere and the interstellar medium. The predictions of magnetospheric birefringence in pulsars have been tested using spectra of the pulse width and fractional polarisation from multifrequency data. The derived spectra offer only partial support for the expected effects of birefringence on the polarisation properties, with only about half of our sample being consistent with the model's predictions. It is noted that for some pulsars these measurements are contaminated by the effects of interstellar scattering. For a number of pulsars in our sample, we have observed significant variations in the amount of Faraday rotation as a function of pulse phase, which is possibly an artefact of scattering. These variations are typically two orders of magnitude smaller than that observed at 1400 MHz by Noutsos et al. (2009), for a different sample of southern pulsars. In this paper we present a possible explanation for the difference in magnitude of this effect between the two frequencies, based on scattering. Finally, we have estimated the magnetospheric emission heights of low-frequency radiation from four pulsars, based on the phase lags between the flux-density and the PA profiles, and the theoretical framework of Blaskiewicz, Cordes & Wasserman (1991). These estimates yielded heights of a few hundred km; at least for PSR B1133+16, this is consistent with emission heights derived based on radius-to-frequency mapping, but is up to a few times larger than the recent upper limit based on pulsar timing., 27 pages, 11 figures, 2 tables, A&A accepted

Published
2015

21. Radio detection of cosmic rays with LOPES (LOPES Collaboration)

Author

R. Obenland, Markus Roth, R. Engel, F. Di Pierro, C. Morello, G. Toma, G. C. Trinchero, H. Rebel, M. Brüggemann, Peter L. Biermann, D. Zimmermann, K. H. Kampert, T. Huege, J.R. Hörandel, Harvey Butcher, H. Bozdog, A. Haungs, R. Glasstetter, P. Doll, H. Gemmeke, J. Wochele, Octavian Sima, S.J. Lafebre, J. Zabierowski, A. Chiavassa, D. Heck, A. Nigl, J. Blümer, Wolfgang Walkowiak, A. Risse, M. Stümpert, Alexandru Bercuci, L. Bähren, Claus Grupen, G. Navarra, H. Ulrich, T. Asch, A.F. Badea, H. Schieler, H. J. Mathes, Y. Kolotaev, K. Bekk, Stijn Buitink, O. Krömer, H.J. Mayer, Kai Daumiller, T. Pierog, A. Weindl, Jan Kuijpers, P. L. Ghia, S. Nehls, J. van Buren, B. Mitrica, Heino Falcke, J. Oehlschläger, A. Horneffer, S. Over, S. Ostapchenko, J. A. Zensus, J. Petrovic, K. Singh, Peter Buchholz, I.M. Brancus, W. D. Apel, M. E. Bertaina, J. Milke, M. Petcu, F. Cossavella, C. Meurer, and S. Plewnia

Subjects
Physics, LOPES, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, General Physics and Astronomy, Astronomy, Cosmic ray, Radiation, Shower, Air shower, Earth's magnetic field, Radio detection, Coherence (physics)
Abstract

Data taken with a radio antenna array in combination with the ground-level air shower experiment KASCADE-Grande at the Forschungszentrum Karlsruhe open up the possibility to measure large extensive air showers with this new technique. The pulse height of the observed radio signals scales with the primary energy of the particles initiating the air shower. The dependence of the radio signal on the angle of the shower axis with respect to the Earth's geomagnetic field and the coherence of the radiation suggest that the radio signal generation is due to the geosynchrotron mechanism.

Published
2006

22. Progress in air shower radio measurements: Detection of distant events

Author

W.D. Apel, T. Asch, A.F. Badea, L. Bähren, K. Bekk, A. Bercuci, M. Bertaina, P.L. Biermann, J. Blümer, H. Bozdog, I.M. Brancus, S. Buitink, M. Brüggemann, P. Buchholz, H. Butcher, A. Chiavassa, F. Cossavella, K. Daumiller, F. Di Pierro, P. Doll, R. Engel, H. Falcke, H. Gemmeke, P.L. Ghia, R. Glasstetter, C. Grupen, A. Haungs, D. Heck, J.R. Hörandel, A. Horneffer, T. Huege, K.H. Kampert, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, H.J. Mathes, H.J. Mayer, C. Meurer, J. Milke, B. Mitrica, C. Morello, G. Navarra, S. Nehls, A. Nigl, R. Obenland, J. Oehlschläger, S. Ostapchenko, S. Over, M. Petcu, J. Petrovic, T. Pierog, S. Plewnia, H. Rebel, A. Risse, M. Roth, H. Schieler, O. Sima, K. Singh, M. Stümpert, G. Toma, G.C. Trinchero, H. Ulrich, J. van Buren, W. Walkowiak, A. Weindl, J. Wochele, J. Zabierowski, J.A. Zensus, and D. Zimmermann

Subjects
Physics, LOPES, business.industry, Astronomy, Radio equipment, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Shower, Air shower, Optics, Pulse-amplitude modulation, Detection theory, business, Coherence (physics)
Abstract

Data taken during half a year of operation of 10 LOPES antennas (LOPES-10), triggered by EAS observed with KASCADE-Grande have been analysed. We report about the analysis of correlations of radio signals measured by LOPES-10 with extensive air shower events reconstructed by KASCADE-Grande, including shower cores at large distances. The efficiency of detecting radio signals induced by air showers up to distances of 700 m from the shower axis has been investigated. The results are discussed with special emphasis on the effects of the reconstruction accuracy for shower core and arrival direction on the coherence of the measured radio signal. In addition, the correlations of the radio pulse amplitude with the primary cosmic ray energy and with the lateral distance from the shower core are studied., Comment: Accepted for publication in Astroparticle Physics

Published
2006

23. Radio emission of highly inclined cosmic ray air showers measured with LOPES - possibility for neutrino detection

Author

S.J. Lafebre, Mstümpert, R. Obenland, J. Petrovic, G.C. Trinchero, Markus Roth, H. J. Mathes, M. Brüggemann, G. Schoonderbeek, R. Glasstetter, S. Plewnia, A. Horneffer, O. Krömer, Gernot Maier, F. Badea, A. Risse, S. Over, P. Doll, U. Klein, G. W. Kant, A. Nigl, Kai Daumiller, Wolfgang Walkowiak, Harvey Butcher, J.R. Hörandel, H. Bozdog, W. D. Apel, J. A. Zensus, L. Bähren, J. Oehlschläger, M. Petcu, D. Zimmermann, H. J. Pepping, R. Engel, Tim Huege, K. Bekk, H. Gemmeke, J. van Buren, H. Rebel, M. E. Bertaina, T. Pierog, C. M. de Vos, Peter Buchholz, K. H. Kampert, A. G. de Bruyn, Piera Luisa Ghia, I.M. Brancus, A. Weindl, Jan Kuijpers, B. Mitrica, Heino Falcke, S. Nehls, J. Blümer, J. Milke, G. Toma, Octavian Sima, H. Schieler, G. Navarra, S. Valchierotti, Stijn Buitink, H.J. Mayer, Andrea Chiavassa, A. Haungs, J. Zabierowski, Alexandru Bercuci, Y. Koopman, F. Di Pierro, C. Morello, W. van Capellen, S. Ostapchenko, C. Grupen, Peter L. Biermann, Y. Kolotaev, Stefan J. Wijnholds, H. Ulrich, J. Wochele, and D. Heck

Subjects
Physics, History, LOPES, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, LOFAR, Astrophysics, Computer Science Applications, Education, Radio telescope, Air shower, KASCADE, Neutrino detector, High Energy Physics::Experiment, Zenith
Abstract

LOPES - LOFAR PrototypE Station (LOFAR - LOw Frequency ARray) is an array of dipole antennas used for the detection of radio emission from cosmic ray air showers. It is co-located and triggered by the KASCADE (KArlsruhe Shower Core and Array Detector) experiment, which also provides information about air shower properties like electron number Ne, muon number Nµ, azimuth and zenith angle. LOPES-10 (the first phase of LOPES, consisting of 10 antennas) detected a significant number of cosmic ray air showers with a zenith angle larger than 50°, and many of those have very high field strengths. The most inclined event that has been detected with LOPES-10 has a zenith angle of almost 80°. This is important, because cosmic ray air showers with large inclinations, triggered close to the ground, would be a signature of neutrino events. Due to the small baseline of the LOPES-10 detector, it is not yet possible to determine accuratelly the radius of curvature of the showers front, which is related to the distance to the maximum of shower development. However, this should be possible in the future with a large baseline radio telescope like LOFAR.

Published
2006

24. Radio Detection of Cosmic Rays with Lopes

Author

A. Nigl, Harvey Butcher, H. Bozdog, Wolfgang Walkowiak, Y. Koopman, G. C. Trinchero, F. Di Pierro, C. Morello, Alexandru Bercuci, G. Navarra, T. Pierog, K. Bekk, Peter L. Biermann, Piera Luisa Ghia, S. Nehls, L. Bähren, Kai Daumiller, O. Krömer, A. Chiavassa, H. Rebel, R. Engel, F. Badea, S. Over, M. Stümpert, H. J. Pepping, S.J. Lafebre, J.R. Hörandel, J. van Buren, Claus Grupen, G. Toma, A. Horneffer, D. Zimmermann, C. M. de Vos, Stefan J. Wijnholds, J. Blümer, H. Gemmeke, J. A. Zensus, Gernot Maier, R. Obenland, J. Oehlschläger, W. van Capellen, Markus Roth, A. Weindl, G. W. Kant, Jan Kuijpers, G. Schoonderbeek, R. Glasstetter, J. Petrovic, H. J. Mathes, M. Brüggemann, U. Klein, M. Petcu, H. Schieler, Peter Buchholz, I.M. Brancus, A. Risse, Tim Huege, P. Doll, Y. Kolotaev, H. Ulrich, M. E. Bertaina, J. Wochele, Octavian Sima, J. Milke, D. Heck, K. H. Kampert, A. G. de Bruyn, Stijn Buitink, W. D. Apel, H.J. Mayer, A. Haungs, S. Plewnia, J. Zabierowski, S. Ostapchenko, B. Mitrica, and Heino Falcke

Subjects
Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astronomy, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Radiation, Atomic and Molecular Physics, and Optics, Shower, Air shower, Earth's magnetic field, Optics, business, Radio detection, Coherence (physics)
Abstract

Contains fulltext : 35498.pdf (Publisher’s version ) (Closed access) Measuring radio pulses from cosmic ray air showers offers various new opportunities. New digital radio receivers allow measurements of these radio pulses even in environments that have lots of radio interference. With high bandwidth ADCs and fast data processing it is possible to store the whole waveform information in digital form and analyse transient events like air showers even after they have been recorded. Digital filtering and beam forming can be used to suppress the radio interference so that it is possible to measure the radio pulses even in radio loud environments. LOPES is a prototype station for the new digital radio interferometer LOFAR and is tailored to measure air showers. For this it is located at the site of the KASCADE-Grande air shower experiment. Already with the first phase of LOPES we have been able to measure radio pulses from air showers and show correlations between the radio pulse height and air shower parameters. The first part gives an introduction and presents the science results of LOPES, while the second part presents the hard- and software that enables LOPES to detect air short pulses.

Published
2006

25. Reconstruction of the energy and depth of maximum of cosmic-ray air showers from LOPES radio measurements

Author

R. Engel, Béatrice Fuchs, J. Rautenberg, O. Krömer, A. Chiavassa, H. Rebel, C. Rühle, Markus Roth, M. Melissas, Katrin Link, M. Ludwig, Claus Grupen, F. Di Pierro, C. Morello, J. Oehlschläger, Octavian Sima, Peter L. Biermann, P. Łuczak, H. Schieler, Karl-Heinz Kampert, N. Palmieri, Heino Falcke, A. Horneffer, J. C. Arteaga-Velázquez, Paula Gina Isar, D. Kang, V. de Souza, A. Weindl, Jan Kuijpers, M. E. Bertaina, L. Bähren, K. Bekk, P. Doll, T. Pierog, H. J. Mathes, Jörg R. Hörandel, J. Wochele, Tim Huege, D. Heck, Gian Carlo Trinchero, Kai Daumiller, H. Gemmeke, A. Schmidt, I.M. Brancus, E. Cantoni, J. A. Zensus, G. Toma, D. Huber, Frank G. Schröder, J. Blümer, W. D. Apel, Alexandra Saftoiu, D. Fuhrmann, A. Haungs, H. Bozdog, and J. Zabierowski

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nuclear and High Energy Physics, FÍSICA DE PARTÍCULAS, LOPES, Astronomy, FOS: Physical sciences, Cosmic ray, Digital radio, Astrophysics, Coincidence, High Energy Physics - Experiment, Interferometry, High Energy Physics - Experiment (hep-ex), KASCADE, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics (astro-ph.IM), Energy (signal processing), Noise (radio)
Abstract

LOPES is a digital radio interferometer located at Karlsruhe Institute of Technology (KIT), Germany, which measures radio emission from extensive air showers at MHz frequencies in coincidence with KASCADE-Grande. In this article, we explore a method (slope method) which leverages the slope of the measured radio lateral distribution to reconstruct crucial attributes of primary cosmic rays. First, we present an investigation of the method on the basis of pure simulations. Second, we directly apply the slope method to LOPES measurements. Applying the slope method to simulations, we obtain uncertainties on the reconstruction of energy and depth of shower maximum Xmax of 13% and 50 g/cm^2, respectively. Applying it to LOPES measurements, we are able to reconstruct energy and Xmax of individual events with upper limits on the precision of 20-25% for the primary energy and 95 g/cm^2 for Xmax, despite strong human-made noise at the LOPES site., 16 pages, accepted by Physical Review D

Published
2014

26. The wavefront of the radio signal emitted by cosmic ray air showers

Author

A. Chiavassa, E. Cantoni, T. Pierog, Tim Huege, A. Horneffer, D. Kang, Paula Gina Isar, Katrin Link, W. D. Apel, M. Melissas, P. Doll, J. Rautenberg, J. Oehlschläger, Alexandra Saftoiu, J. Wochele, Heino Falcke, Octavian Sima, M. E. Bertaina, D. Heck, M. Ludwig, A. Weindl, Ralph Engel, Jan Kuijpers, F. Di Pierro, J. Zabierowski, P. Łuczak, N. Palmieri, Andreas Haungs, D. Huber, A. Schmidt, C. Rühle, H. J. Mathes, K. Bekk, H. Rebel, H. Bozdog, J. A. Zensus, Markus Roth, F.G. Schröder, S. Schoo, J. Blümer, L. Bähren, O. Krömer, I.M. Brancus, H. Schieler, Karl-Heinz Kampert, Béatrice Fuchs, H. Gemmeke, G. Toma, Claus Grupen, C. Morello, Peter L. Biermann, V. de Souza, Jörg R. Hörandel, J.C. Arteaga-Velázquez, Kai Daumiller, and G.C. Trinchero

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Cosmic ray, High Energy Physics - Experiment, Antenna array, High Energy Physics - Experiment (hep-ex), Optics, ddc:530, Ligand cone angle, Instrumentation and Methods for Astrophysics (astro-ph.IM), Zenith, Cherenkov radiation, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Wavefront, LOPES, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, ASTROFÍSICA, KASCADE, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, business
Abstract

Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above $10^{17}\,$eV and zenith angles smaller than $45^\circ$, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances $\gtrsim 50\,$m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately $140\,$g/cm$^2$. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, $X_\mathrm{max}$, better than $30\,$g/cm$^2$. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too., Comment: accepted by JCAP

Published
2014
Full Text
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27. MEASURING RADIO PULSES FROM AIR SHOWERS WITH LOPES

Author

G. C. Trinchero, M. Petcu, A. Risse, Y. Koopman, F. Di Pierro, C. Morello, Peter L. Biermann, A. Chiavassa, F. Badea, Marcio Aparecido Muller, M. Stümpert, A. Horneffer, Stefan J. Wijnholds, H. J. Pepping, G. de Bruyn, H. Schieler, J. Wochele, H.O. Klages, S. Ostapchenko, H.J. Gils, S. Plewnia, Gernot Maier, J. van Buren, C. M. de Vos, K. Bekk, D. Heck, Peter Buchholz, Tim Huege, J. A. Zensus, A. Weindl, M. Brüggemann, I.M. Brancus, Jan Kuijpers, P. Doll, A. Nigl, B. Mitrica, Heino Falcke, R. Engel, H.J. Mayer, Wolfgang Walkowiak, Harvey Butcher, A. Haungs, Kai Daumiller, O. Krömer, H. Bozdog, T. Thouw, G. W. Kant, F. Feßler, J. Zabierowski, R. Obenland, S. Zagromski, G. Schoonderbeek, R. Glasstetter, T. Antoni, Alexandru Bercuci, S. Valchierotti, P. L. Ghia, Markus Roth, H. Gemmeke, H. Blümer, G. Toma, J. Oehlschläger, S. Nehls, J. Engler, S.J. Lafebre, C. Büttner, K. H. Kampert, M. E. Bertaina, W. van Capellen, J. Milke, G. Navarra, Y. Kolotaev, L. Bähren, S. Over, J.R. Hörandel, D. Zimmermann, H. Ulrich, U. Klein, H. Rebel, J. Scholz, H. J. Mathes, and W. D. Apel

Subjects
Physics, Beamforming, Nuclear and High Energy Physics, LOPES, Acoustics, Astronomy, Astronomy and Astrophysics, Digital radio, LOFAR, Interference (wave propagation), Atomic and Molecular Physics, and Optics, Electromagnetic interference, Air shower, Radio wave
Abstract

LOFAR is a new digital radio interferometer that is being build in The Netherlands. By sampling the radio waves with fast ADCs it can digitally store the whole waveform information and analyze transient events like air showers after they have been recorded. To demonstrate its ability to measure air showers we are building LOPES (a LOFAR PrototypeStation) at the site of an existing air shower array (KASCADE-Grande). The first phase consisting of 10 antennas is already running. It has demonstrated how digital interference suppression and beamforming can overcome the problem of radio interference and pick out air shower events.

Published
2005

28. Thunderstorm Observations by Air-Shower Radio Antenna Arrays

Author

H. J. Mathes, Jörg R. Hörandel, M. Ludwig, C. Rühle, A. Horneffer, Claus Grupen, J.C. Arteaga, F.G. Schröder, D. Huber, Markus Roth, Kai Daumiller, J. Blümer, G.C. Trinchero, Peter Buchholz, Moses Ender, G. Toma, I.M. Brancus, F. Di Pierro, C. Morello, A. Weindl, L. Bähren, Jan Kuijpers, O. Krömer, P.G. Isar, Peter L. Biermann, H. Gemmeke, A. Schmidt, T. Pierog, M. Wommer, M. Melissas, J. Rautenberg, S. Nehls, D. Kang, Heino Falcke, M. Finger, Tim Huege, K. Bekk, J. Wochele, V. de Souza, Octavian Sima, D. Heck, K. Link, J. A. Zensus, A. Haungs, E. Cantoni, J. Zabierowski, P. Doll, Ralph Engel, J. Oehlschläger, M. E. Bertaina, Stijn Buitink, A. Chiavassa, H. Rebel, W. D. Apel, H. Schieler, Karl-Heinz Kampert, P. Łuczak, N. Palmieri, H. Bozdog, Alexandra Saftoiu, and D. Fuhrmann

Subjects
Atmospheric Science, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Aerospace Engineering, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Broadband, Instrumentation and Methods for Astrophysics (astro-ph.IM), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, LOPES, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Lightning, Computational physics, Lightning strike, Geophysics, Air shower, Space and Planetary Science, Thunderstorm, RÁDIO, General Earth and Planetary Sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Radio wave
Abstract

Relativistic, charged particles present in extensive air showers (EAS) lead to a coherent emission of radio pulses which are measured to identify the shower initiating high-energy cosmic rays. Especially during thunderstorms, there are additional strong electric fields in the atmosphere, which can lead to further multiplication and acceleration of the charged particles and thus have influence on the form and strength of the radio emission. For a reliable energy reconstruction of the primary cosmic ray by means of the measured radio signal it is very important to understand how electric fields affect the radio emission. In addition, lightning strikes are a prominent source of broadband radio emissions that are visible over very long distances. This, on the one hand, causes difficulties in the detection of the much lower signal of the air shower. On the other hand the recorded signals can be used to study features of the lightning development. The detection of cosmic rays via the radio emission and the influence of strong electric fields on this detection technique is investigated with the LOPES experiment in Karlsruhe, Germany. The important question if a lightning is initiated by the high electron density given at the maximum of a high-energy cosmic-ray air shower is also investigated, but could not be answered by LOPES. But, these investigations exhibit the capabilities of EAS radio antenna arrays for lightning studies. We report about the studies of LOPES measured radio signals of air showers taken during thunderstorms and give a short outlook to new measurements dedicated to search for correlations of lightning and cosmic rays.

Published
2013

29. LOPES-3D, an antenna array for full signal detection of air-shower radio emission

Author

D. Kang, P. Doll, Heino Falcke, Béatrice Fuchs, Jörg R. Hörandel, A. Horneffer, F. Di Pierro, C. Morello, J.C. Arteaga, A. Chiavassa, M. Wommer, J. Rautenberg, A. Weindl, Jan Kuijpers, Peter L. Biermann, Kai Daumiller, L. Bähren, O. Krömer, K. Bekk, C. Rühle, J. Oehlschläger, J. Blümer, Claus Grupen, P.G. Isar, V. de Souza, H. Bozdog, M. Finger, M. E. Bertaina, G.C. Trinchero, Markus Roth, H. Rebel, P. Łuczak, K. Link, N. Palmieri, A. Haungs, M. Melissas, J. Zabierowski, H. J. Mathes, H. Schieler, M. Ludwig, Alexandra Saftoiu, Karl-Heinz Kampert, G. Toma, F.G. Schröder, D. Huber, A. Schmidt, D. Fuhrmann, T. Pierog, E. Cantoni, Ralph Engel, W. D. Apel, Peter Buchholz, J. A. Zensus, I.M. Brancus, H. Gemmeke, Tim Huege, J. Wochele, Octavian Sima, and D. Heck

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Antenna array, Optics, Air shower, Detection theory, Antenna (radio), business, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instrumentation, Sensitivity (electronics), Energy (signal processing)
Abstract

To better understand the radio signal emitted by extensive air-showers and to further develop the radio detection technique of high-energy cosmic rays, the LOPES experiment was reconfigured to LOPES-3D. LOPES-3D is able to measure all three vectorial components of the electric field of radio emission from cosmic ray air showers. The additional measurement of the vertical component ought to increase the reconstruction accuracy of primary cosmic ray parameters like direction and energy, provides an improved sensitivity to inclined showers, and will help to validate simulation of the emission mechanisms in the atmosphere. LOPES-3D will evaluate the feasibility of vectorial measurements for large scale applications. In order to measure all three electric field components directly, a tailor-made antenna type (tripoles) was deployed. The change of the antenna type necessitated new pre-amplifiers and an overall recalibration. The reconfiguration and the recalibration procedure are presented and the operationality of LOPES-3D is demonstrated.

Published
2013

30. LOFAR: The LOw-Frequency ARray

Author

M. P. van Haarlem, M. W. Wise, A. W. Gunst, G. Heald, J. P. McKean, J. W. T. Hessels, A. G. de Bruyn, R. Nijboer, J. Swinbank, R. Fallows, M. Brentjens, A. Nelles, R. Beck, H. Falcke, R. Fender, J. Hörandel, L. V. E. Koopmans, G. Mann, G. Miley, H. Röttgering, B. W. Stappers, R. A. M. J. Wijers, S. Zaroubi, M. van den Akker, A. Alexov, J. Anderson, K. Anderson, A. van Ardenne, M. Arts, A. Asgekar, I. M. Avruch, F. Batejat, L. Bähren, M. E. Bell, M. R. Bell, I. van Bemmel, P. Bennema, M. J. Bentum, G. Bernardi, P. Best, L. Bîrzan, A. Bonafede, A.-J. Boonstra, R. Braun, J. Bregman, F. Breitling, R. H. van de Brink, J. Broderick, P. C. Broekema, W. N. Brouw, M. Brüggen, H. R. Butcher, W. van Cappellen, B. Ciardi, T. Coenen, J. Conway, A. Coolen, A. Corstanje, S. Damstra, O. Davies, A. T. Deller, R.-J. Dettmar, G. van Diepen, K. Dijkstra, P. Donker, A. Doorduin, J. Dromer, M. Drost, A. van Duin, J. Eislöffel, J. van Enst, C. Ferrari, W. Frieswijk, H. Gankema, M. A. Garrett, F. de Gasperin, M. Gerbers, E. de Geus, J.-M. Grießmeier, T. Grit, P. Gruppen, J. P. Hamaker, T. Hassall, M. Hoeft, H. A. Holties, A. Horneffer, A. van der Horst, A. van Houwelingen, A. Huijgen, M. Iacobelli, H. Intema, N. Jackson, V. Jelic, A. de Jong, E. Juette, D. Kant, A. Karastergiou, A. Koers, H. Kollen, V. I. Kondratiev, E. Kooistra, Y. Koopman, A. Koster, M. Kuniyoshi, M. Kramer, G. Kuper, P. Lambropoulos, C. Law, J. van Leeuwen, J. Lemaitre, M. Loose, P. Maat, G. Macario, S. Markoff, J. Masters, R. A. McFadden, D. McKay-Bukowski, H. Meijering, H. Meulman, M. Mevius, E. Middelberg, R. Millenaar, J. C. A. Miller-Jones, R. N. Mohan, J. D. Mol, J. Morawietz, R. Morganti, D. D. Mulcahy, E. Mulder, H. Munk, L. Nieuwenhuis, R. van Nieuwpoort, J. E. Noordam, M. Norden, A. Noutsos, A. R. Offringa, H. Olofsson, A. Omar, E. Orrú, R. Overeem, H. Paas, M. Pandey-Pommier, V. N. Pandey, R. Pizzo, A. Polatidis, D. Rafferty, S. Rawlings, W. Reich, J.-P. de Reijer, J. Reitsma, G. A. Renting, P. Riemers, E. Rol, J. W. Romein, J. Roosjen, M. Ruiter, A. Scaife, K. van der Schaaf, B. Scheers, P. Schellart, A. Schoenmakers, G. Schoonderbeek, M. Serylak, A. Shulevski, J. Sluman, O. Smirnov, C. Sobey, H. Spreeuw, M. Steinmetz, C. G. M. Sterks, H.-J. Stiepel, K. Stuurwold, M. Tagger, Y. Tang, C. Tasse, I. Thomas, S. Thoudam, M. C. Toribio, B. van der Tol, O. Usov, M. van Veelen, A.-J. van der Veen, S. ter Veen, J. P. W. Verbiest, R. Vermeulen, N. Vermaas, C. Vocks, C. Vogt, M. de Vos, E. van der Wal, R. van Weeren, H. Weggemans, P. Weltevrede, S. White, S. J. Wijnholds, T. Wilhelmsson, O. Wucknitz, S. Yatawatta, P. Zarka, A. Zensus, J. van Zwieten, Netherlands Institute for Radio Astronomy (ASTRON), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Institute of Mathematical and Physical Sciences, Radboud university [Nijmegen], Laboratoire de Chimie Physique Moléculaire (LCPM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Radioastronomie (MPIFR), University of Southampton, Leibniz-Institut für Astrophysik Potsdam (AIP), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Medical Center Haaglanden, SRON Netherlands Institute for Space Research (SRON), University of Edinburgh, Jacobs University [Bremen], Technische Universität Dresden = Dresden University of Technology (TU Dresden), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Department of Reproduction and Development, Erasmus University Rotterdam, London Institute for Mathematical Sciences, Netherlands Centre for Biodiversity, Leiden, The Netherlands, Thüringer Landessternwarte Tautenburg (TLS), Laboratoire Réactions et Génie des Procédés (LRGP), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Medstar Research Institute, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Plant Research International, Business Unit Bioscience, Wageningen University and Research [Wageningen] (WUR), Dipartimento di Matematica 'Guido Castelnuovo' [Roma I] (Sapienza University of Rome), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Centre de Mathématiques Laurent Schwartz (CMLS), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Peuplements végétaux et bioagresseurs en milieu tropical (UMR PVBMT), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université de La Réunion (UR), Ruhr-Universität Bochum [Bochum], Oxford Astrophysics, University of Oxford [Oxford], Amsterdam Center for Multiscale Modeling, Vrije Universiteit Amsterdam [Amsterdam] (VU), Vrije Universiteit Medical Centre (VUMC), Queen's Medical Centre, National Radio Astronomy Observatory (NRAO), University of Oulu, Department of Economics, Bryant University, Center for Agricultural Research in Suriname CELOS and Department of Biology, Anton de Kom Universiteit van Suriname - Anton de Kom University of Suriname [Paramaribo] (UVS), DLR Institute of Aerospace Medicine, Deutsches Zentrum für Luft- und Raumfahrt [Köln] (DLR), Onsala Space Observatory (OSO), Chalmers University of Technology [Göteborg], Geophysical Institute [Bergen] (GFI / BiU), University of Bergen (UiB), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Department of Astronomy and Astrophysics [PennState], Pennsylvania State University (Penn State), Penn State System-Penn State System, Academic Medical Center - Academisch Medisch Centrum [Amsterdam] (AMC), School of Physics and Astronomy [Southampton], Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Rhodes University, Grahamstown, Center for Information Technology CIT, Université de Groningen, Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Center for Operations and Econometrics, Center of Operation Research and Econometrics [Louvain] (CORE), Université Catholique de Louvain = Catholic University of Louvain (UCL)-Université Catholique de Louvain = Catholic University of Louvain (UCL), Finca El Encin, Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario (IMIDRA), Department of Surgery (EINDHOVEN - Surgery), Catharina Hospital, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, ANR-09-JCJC-0001,OPALES(2009), Astronomy, KVI - Center for Advanced Radiation Technology, Radboud University [Nijmegen], Universiteit Leiden, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), University of Oxford, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Harvard University-Smithsonian Institution, UMR Peuplement Végétaux et Bioagresseurs en Milieu Tropical (UMR PVBMT - INRA), Institut National de la Recherche Agronomique (INRA), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden (TUD), university Rotterdam, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Wageningen University and Research Centre [Wageningen] (WUR), Università degli Studi di Roma 'La Sapienza' [Rome], Department of Physics, University of Crete [Heraklion] (UOC), Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas (FORTH), Anton de Kom University of Suriname, Geophysical Institute [Bergen], University of Bergen (UIB), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Rhodes University, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS), SKA South Africa, Ska South Africa, Center for Operations and Econometrics, Universit´e catholique de Louvain and Fonds National de la Recherche Scientifique, Harvard University [Cambridge]-Smithsonian Institution, Observatoire de Paris - Site de Paris (OP), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), ANR-09-JCJC-0001,OPALES,nOn-thermal Processes in gALaxy cluStErs(2009), High Energy Astrophys. & Astropart. Phys (API, FNWI), Van Haarlem, M.P., Wise, M.W., Gunst, A.W., Heald, G., McKean, J.P., Hessels, J.W.T., De Bruyn, A.G., Nijboer, R., Swinbank, J., Fallows, R., Brentjens, M., Nelles, A., Beck, R., Falcke, H., Fender, R., Hörandel, J., Koopmans, L.V.E., Mann, G., Miley, G., Röttgering, H., Stappers, B.W., Wijers, R.A.M.J., Zaroubi, S., Van Den Akker, M., Alexov, A., Anderson, J., Anderson, K., Van Ardenne, A., Arts, M., Asgekar, A., Avruch, I.M., Batejat, F., Bähren, L., Bell, M.E., Bell, M.R., Van Bemmel, I., Bennema, P., Bentum, M.J., Bernardi, G., Best, P., Bîrzan, L., Bonafede, A., Boonstra, A.-J., Braun, R., Bregman, J., Breitling, F., Van De Brink, R.H., Broderick, J., Broekema, P.C., Brouw, W.N., Brüggen, M., Butcher, H.R., Van Cappellen, W., Ciardi, B., Coenen, T., Conway, J., Coolen, A., Corstanje, A., Damstra, S., Davies, O., Deller, A.T., Dettmar, R.-J., Van Diepen, G., Dijkstra, K., Donker, P., Doorduin, A., Dromer, J., Drost, M., Van Duin, A., Eislöffel, J., Van Enst, J., Ferrari, C., Frieswijk, W., Gankema, H., Garrett, M.A., De Gasperin, F., Gerbers, M., De Geus, E., Grießmeier, J.-M., Grit, T., Gruppen, P., Hamaker, J.P., Hassall, T., Hoeft, M., Holties, H.A., Horneffer, A., Van Der Horst, A., Van Houwelingen, A., Huijgen, A., Iacobelli, M., Intema, H., Jackson, N., Jelic, V., De Jong, A., Juette, E., Kant, D., Karastergiou, A., Koers, A., Kollen, H., Kondratiev, V.I., Kooistra, E., Koopman, Y., Koster, A., Kuniyoshi, M., Kramer, M., Kuper, G., Lambropoulos, P., Law, C., Van Leeuwen, J., Lemaitre, J., Loose, M., Maat, P., Macario, G., Markoff, S., Masters, J., McFadden, R.A., McKay-Bukowski, D., Meijering, H., Meulman, H., Mevius, M., Middelberg, E., Millenaar, R., Miller-Jones, J.C.A., Mohan, R.N., Mol, J.D., Morawietz, J., Morganti, R., Mulcahy, D.D., Mulder, E., Munk, H., Nieuwenhuis, L., Van Nieuwpoort, R., Noordam, J.E., Norden, M., Noutsos, A., Offringa, A.R., Olofsson, H., Omar, A., Orrú, E., Overeem, R., Paas, H., Pandey-Pommier, M., Pandey, V.N., Pizzo, R., Polatidis, A., Rafferty, D., Rawlings, S., Reich, W., De Reijer, J.-P., Reitsma, J., Renting, G.A., Riemers, P., Rol, E., Romein, J.W., Roosjen, J., Ruiter, M., Scaife, A., Van Der Schaaf, K., Scheers, B., Schellart, P., Schoenmakers, A., Schoonderbeek, G., Serylak, M., Shulevski, A., Sluman, J., Smirnov, O., Sobey, C., Spreeuw, H., Steinmetz, M., Sterks, C.G.M., Stiepel, H.-J., Stuurwold, K., Tagger, M., Tang, Y., Tasse, C., Thomas, I., Thoudam, S., Toribio, M.C., Van Der Tol, B., Usov, O., Van Veelen, M., Van Der Veen, A.-J., Ter Veen, S., Verbiest, J.P.W., Vermeulen, R., Vermaas, N., Vocks, C., Vogt, C., De Vos, M., Van Der Wal, E., Van Weeren, R., Weggemans, H., Weltevrede, P., White, S., Wijnholds, S.J., Wilhelmsson, T., Wucknitz, O., Yatawatta, S., Zarka, P., Zensus, A., and Van Zwieten, J.

Subjects
instrumentation: interferometers -radio continuum: general -radio lines: general -dark ages, Computer science, Astronomy, INTERPLANETARY SCINTILLATION, radio continuum: general, 7. Clean energy, 01 natural sciences, Precision Array for Probing the Epoch of Reionization, law.invention, Observatory, law, first stars - telescopes, dark ages, instrumentation: interferometers, 010303 astronomy & astrophysics, Telescope, UNDERSTANDING RADIO POLARIMETRY, Instrumentation: Interferometer, SELF-CALIBRATION, Interferometry, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, reionization, Astrophysics - Instrumentation and Methods for Astrophysics, radio lines: general, first stars, Z-GREATER-THAN-5.7 QUASARS, FOS: Physical sciences, Murchison Widefield Array, 0103 physical sciences, RAY AIR-SHOWERS, Angular resolution, dark ages, reionization, first stars, Instrumentation and Methods for Astrophysics (astro-ph.IM), Remote sensing, 010308 nuclear & particles physics, telescopes, Astronomy and Astrophysics, LOFAR, Astronomy and Astrophysic, Sextant (astronomical), Dark ages, reionization, first star, Space and Planetary Science, [SDU]Sciences of the Universe [physics], PROBE WMAP OBSERVATIONS, DIGITAL SKY SURVEY, HIGH-REDSHIFT, MONTE-CARLO SIMULATIONS, INTERGALACTIC MEDIUM
Abstract

LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. LOFAR's new capabilities, techniques and modus operandi make it an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results from the commissioning phase of this new radio observatory., Comment: 56 pages, 34 figures, accepted for publication by A&A

Published
2013
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31. Detecting cosmic rays with the LOFAR radio telescope

Author

P. Maat, M. J. Norden, J. M. Anderson, N. J. Vermaas, E. de Geus, Sarod Yatawatta, Stefan J. Wijnholds, A. de Jong, J. D. Mol, Ben Stappers, C. Vogt, Philip Best, Pim Schellart, Stijn Buitink, D. McKay-Bukowski, M. Pandey-Pommier, Joel N. Bregman, H. Munk, Marcus Brüggen, Matthias Hoeft, P. Bennema, Jason W. T. Hessels, Charlotte Sobey, Benedetta Ciardi, M. de Vos, R.V. van Nieuwpoort, J. E. Enriquez, A. Alexov, R. J. van Weeren, S. Duscha, L. Bähren, Ph. Zarka, Aris Karastergiou, Gottfried Mann, Heino Falcke, Rene C. Vermeulen, V. I. Kondratiev, A. Horneffer, Michael W. Wise, Gianni Bernardi, R. Pizzo, D. D. Mulcahy, M. Kuniyoshi, Giulia Macario, Jörg R. Hörandel, Michael Kramer, Ralph A. M. J. Wijers, Richard Fallows, John McKean, Arthur Corstanje, Cyril Tasse, J. W. Broderick, A. H. W. M. Coolen, A. Nelles, George Heald, A. Zensus, A. Schoenmakers, John W. Romein, Michiel A. Brentjens, John D. Swinbank, C. Toribio, Jean-Mathias Grießmeier, Maria Krause, M. A. Garrett, Olaf Scholten, Dominik J. Schwarz, Y. Tang, M. van den Akker, T. E. Hassall, Oleg Smirnov, H. Paas, T. Grit, James Miller-Jones, R. Nijboer, Matthias Steinmetz, Marco Iacobelli, J. P. Hamaker, Emanuela Orru, C. W. James, J. van Leeuwen, J. Kohler, Chiara Ferrari, Christian Vocks, Jochen Eislöffel, Mark J. Bentum, Gerard H. Kuper, R. Overeem, A. G. Polatidis, I. M. Avruch, A. Renting, F. de Gasperin, W. Frieswijk, S. ter Veen, Martin Bell, E. Juette, Wouter Klijn, M. Mevius, Sera Markoff, H. A. Holties, Olaf Wucknitz, Rainer Beck, J. Sluman, H. J. A. Röttgering, Satyendra Thoudam, F. Breitling, High Energy Astrophys. & Astropart. Phys (API, FNWI), Radboud University [Nijmegen], SETI Institute, Netherlands Institute for Radio Astronomy (ASTRON), Max-Planck-Institut für Radioastronomie (MPIFR), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Erlangen Centre for Astroparticle Physics (ECAP), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Max-Planck-Institut für Extraterrestrische Physik (MPE), Kernfysisch Versneller Instituut, Univ. of Groningen (KVI), University of Groningen [Groningen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), SRON Netherlands Institute for Space Research (SRON), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire de Chimie Physique Moléculaire (LCPM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, University of Edinburgh, Leibniz-Institut für Astrophysik Potsdam (AIP), University of Southampton, Jacobs University [Bremen], London Institute for Mathematical Sciences, Hamburger Sternwarte/Hamburg Observatory, Universität Hamburg (UHH), Medstar Research Institute, Thüringer Landessternwarte Tautenburg (TLS), Institute of Mathematical and Physical Sciences, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Ruhr-Universität Bochum [Bochum], Oxford Astrophysics, University of Oxford, Karlsruhe Institute of Technology (KIT), University of Oulu, Center for Agricultural Research in Suriname CELOS and Department of Biology, Anton de Kom Universiteit van Suriname - Anton de Kom University of Suriname [Paramaribo] (UVS), Center for Information Technology CIT, Université de Groningen, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Interactions Son Musique Mouvement, Sciences et Technologies de la Musique et du Son (STMS), Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Rhodes University, Grahamstown, SKA South Africa, Ska South Africa, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Kapteyn Astronomical Institute [Groningen], ANR-09-JCJC-0001,OPALES(2009), European Project: 227610,EC:FP7:ERC,ERC-2008-AdG,LOFAR-AUGER(2009), Astronomy, Research unit Astroparticle Physics, Radboud university [Nijmegen], Harvard University [Cambridge]-Smithsonian Institution, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden [Leiden], University of Oxford [Oxford], École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Anton de Kom University of Suriname, Université Pierre et Marie Curie - Paris 6 (UPMC)-IRCAM-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-IRCAM-Centre National de la Recherche Scientifique (CNRS), Rhodes University, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and ANR-09-JCJC-0001,OPALES,nOn-thermal Processes in gALaxy cluStErs(2009)

Subjects
EWI-24497, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, EXTENSIVE AIR-SHOWERS, 01 natural sciences, Electromagnetic interference, Radio telescope, CODALEMA, 0103 physical sciences, instrumentation: interferometers, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, LOFAR, METIS-302713, methods: data analysis, SIMULATIONS, PULSES, Interferometry, Space and Planetary Science, astroparticle physics, [SDU]Sciences of the Universe [physics], ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ARRAY, astroparticle physics – methods: data analysis – instrumentation: interferometers, Antenna (radio), EMISSION, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing), IR-89518
Abstract

International audience; 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.

Published
2013

32. Radio Measurements of Air Showers with LOPES

Author

A. Horneffer, D. Kang, C. Grupen, M. Ludwig, I.M. Brancus, J. Wochele, Octavian Sima, M. E. Bertaina, A. Schmidt, H. Gemmeke, J. Rautenberg, Tim Huege, P. Łuczak, N. Palmieri, D. Heck, E. Cantoni, Ralph Engel, D. Fuhrmann, Paula Gina Isar, K. Link, A. Haungs, F. Di Pierro, C. Morello, J. Zabierowski, W. D. Apel, Peter L. Biermann, O. Krömer, L. Bähren, P. Doll, Heino Falcke, H. Bozdog, A. Weindl, Jan Kuijpers, Kai Daumiller, H. Rebel, H. Schieler, Béatrice Fuchs, A. Saftoiu, K. H. Kampert, T. Pierog, Frank G. Schröder, Jörg R. Hörandel, J. A. Zensus, V. de Souza, J. Blümer, J. C. Arteaga-Velázquez, G. Toma, G.C. Trinchero, M. Melissas, J. Oehlschläger, D. Huber, C. Rühle, Markus Roth, Andrea Chiavassa, H. J. Mathes, and K. Bekk

Subjects
Physics, History, Meteorology, LOPES, Astronomy, Ambient noise level, Computer Science Applications, Education, Antenna array, Amplitude, Calibration, Angular resolution, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Energy (signal processing), Noise (radio), Remote sensing
Abstract

LOPES is a digital antenna array for the radio measurement of cosmic-ray air showers at energies around 1017 eV. It is triggered by the KASCADE-Grande air-shower array at the Karlsruhe Institute of Technology (KIT), Germany. Because of an absolute amplitude calibration and a sophisticated data analysis, LOPES can test models for the radio emission to an up-to-now unachieved level, thus improving our understanding of the radio emission mechanisms. Recent REAS simulations of the air-shower radio emission come closer to the measurements than any previously tested simulations. We have determined the radio-reconstruction precision of interesting air-shower parameters by comparing LOPES reconstructions to both REAS simulations and KASCADE-Grande measurements, and present our latest results for the angular resolution, the energy and the Xmax reconstruction based on the radio measurement of about 500 air showers. Although the precision of LOPES is limited by the high level of anthropogenic noise at KIT, it opens a promising perspective for next-generation radio arrays in regions with a lower ambient noise level.

Published
2013

33. Comparison of LOPES measurements with CoREAS and REAS 3.11 simulations

Author

D. Kang, M. Haug, G. C. Trinchero, K. Bekk, T. Pierog, J. Wochele, H. J. Mathes, H. Gemmeke, D. Heck, A. Schmidt, Claus Grupen, H. Rebel, A. Horneffer, P. Doll, M. Melissas, L. Bähren, P. Łuczak, N. Palmieri, J. Oehlschläger, D. Fuhrmann, H. Bozdog, V. de Souza, F. Di Pierro, C. Morello, A. Weindl, Heino Falcke, Jan Kuijpers, Tim Huege, C. Rühle, M. Ludwig, Peter L. Biermann, O. Krömer, Béatrice Fuchs, R. Engel, K. H. Kampert, A. Saftoiu, Markus Roth, Paula Gina Isar, Kai Daumiller, J. A. Zensus, W. D. Apel, J. Rautenberg, Octavian Sima, H. Schieler, G. Toma, J.R. Hörandel, D. Huber, Frank G. Schröder, I.M. Brancus, J. Blümer, J. C. Arteaga-Velázquez, M. E. Bertaina, K. Link, A. Haungs, J. Zabierowski, and Andrea Chiavassa

Subjects
Physics, Formalism (philosophy of mathematics), Optics, Amplitude, LOPES, business.industry, Monte carlo code, Astronomy, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, business, Computational physics
Abstract

In the previous years, LOPES emerged as a very successful experiment measuring the radio emission from air showers in the MHz frequency range. In parallel, the theoretical description of radio emission was developed further and REAS became a widely used simulation Monte Carlo code. REAS 3 as well as CoREAS are based on the endpoint formalism, i.e. they calculate the emission of the air-shower without assuming specific emission mechanisms. While REAS 3 is based on histograms derived from CORSIKA simulations, CoREAS is directly implemented into CORSIKA without loss of information due to histogramming of the particle distributions. In contrast to the earlier versions of REAS, the newest version REAS 3.11 and CoREAS take into account a realistic atmospheric refractive index. To improve the understanding of the emission processes and judge the quality of the simulations, we compare their predictions with high-quality events measured by LOPES. We present results concerning the lateral distribution measured with 30 east-west aligned LOPES antennas. Only the simulation codes including the refractive index (REAS 3.11 and CoREAS) are able to reproduce the slope of measured lateral distributions, but REAS 3.0 predicts too steep lateral distributions, and does not predict rising lateral distributions as seen in a few LOPES events. Moreover, REAS 3.11 predicts an absolute amplitude compatible with the LOPES measurements.

Published
2013

34. Comparing LOPES measurements of air-shower radio emission with REAS 3.11 and CoREAS simulations

Author

Alexandra Saftoiu, Béatrice Fuchs, D. Huber, Jörg R. Hörandel, K. Link, G.C. Trinchero, F. Di Pierro, A. Haungs, C. Morello, C. Rühle, D. Fuhrmann, W. D. Apel, J. Blümer, H. Bozdog, Paula Gina Isar, J. Rautenberg, M. Melissas, Markus Roth, Peter L. Biermann, J. Zabierowski, J.C. Arteaga-Velázquez, T. Pierog, A. Chiavassa, G. Toma, Tim Huege, P. Łuczak, N. Palmieri, Kai Daumiller, J. Oehlschläger, E. Cantoni, Ralph Engel, A. Schmidt, Heino Falcke, M. E. Bertaina, J. A. Zensus, I.M. Brancus, A. Horneffer, Claus Grupen, K. Bekk, P. Doll, V. de Souza, A. Weindl, Jan Kuijpers, H. Gemmeke, H. Rebel, H. Schieler, Karl-Heinz Kampert, J. Wochele, Octavian Sima, D. Heck, M. Ludwig, H. J. Mathes, F.G. Schröder, L. Bähren, O. Krömer, and D. Kang

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), LOPES, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Askaryan effect, Amplitude, Air shower, Earth's magnetic field, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Astrophysics - High Energy Astrophysical Phenomena, RAIOS CÓSMICOS, Radio wave
Abstract

Cosmic ray air showers emit radio pulses at MHz frequencies, which can be measured with radio antenna arrays - like LOPES at the Karlsruhe Institute of Technology in Germany. To improve the understanding of the radio emission, we test theoretical descriptions with measured data. The observables used for these tests are the absolute amplitude of the radio signal, and the shape of the radio lateral distribution. We compare lateral distributions of more than 500 LOPES events with two recent and public Monte Carlo simulation codes, REAS 3.11 and CoREAS (v 1.0). The absolute radio amplitudes predicted by REAS 3.11 are in good agreement with the LOPES measurements. The amplitudes predicted by CoREAS are lower by a factor of two, and marginally compatible with the LOPES measurements within the systematic scale uncertainties. In contrast to any previous versions of REAS, REAS 3.11 and CoREAS now reproduce the shape of the measured lateral distributions correctly. This reflects a remarkable progress compared to the situation a few years ago, and it seems that the main processes for the radio emission of air showers are now understood: The emission is mainly due to the geomagnetic deflection of the electrons and positrons in the shower. Less important but not negligible is the Askaryan effect (net charge variation). Moreover, we confirm that the refractive index of the air plays an important role, since it changes the coherence conditions for the emission: Only the new simulations including the refractive index can reproduce rising lateral distributions which we observe in a few LOPES events. Finally, we show that the lateral distribution is sensitive to the energy and the mass of the primary cosmic ray particles., Comment: Attention: results and conclusion partly changed due to updated calibration. See Astroparticle Physics 75 (2016) 72-74; arXiv:1507.07389

Published
2013
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35. Wide-band simultaneous observations of pulsars: disentangling dispersion measure and profile variations

Author

P. Maat, Benjamin Stappers, Heino Falcke, Charlotte Sobey, Emanuela Orrú, Jason W. T. Hessels, E. Rol, L. Bähren, H. Meulman, Joris P. W. Verbiest, C. Tasse, A. Alexov, Matthias Hoeft, M. A. Garrett, Sarod Yatawatta, James Miller-Jones, Evan Keane, Michael Kramer, S. ter Veen, J. Masters, A. W. Gunst, Casey J. Law, Jochen Eislöffel, B. Scheers, Maaijke Mevius, T. E. Hassall, J. W. Broderick, R. C. Vermeulen, B. Ciardi, Martin Bell, John McKean, Luitje Koopmans, J. E. Noordam, Gerard H. Kuper, Annalisa Bonafede, Harvey Butcher, Sera Markoff, M. P. van Haarlem, E. J. Daw, Rudy Wijnands, M. Kuniyoshi, V. I. Kondratiev, M. Pandey-Pommier, A. Noutsos, K. Zagkouris, Michael R. Bell, H. Paas, J. Sluman, Michiel A. Brentjens, Ashish Asgekar, Roberto Pizzo, Marcus Brüggen, C. G. M. Sterks, W. Reich, R. A. Osten, Albert-Jan Boonstra, Michel Tagger, Stephane Corbel, A. G. Polatidis, P.G. Jonker, M. Gerbers, Stefan J. Wijnholds, J. van Leeuwen, H. Spreeuw, A. de Jong, Matthias Steinmetz, R. J. van Weeren, P. Zarka, K. Lazaridis, George Heald, Mark J. Bentum, G. M. Loose, W. N. Brouw, Patrick Weltevrede, V. S. Dhillon, Aris Karastergiou, Michael W. Wise, Gianni Bernardi, M. Serylak, Rob Fender, Ralph A. M. J. Wijers, H. J. A. Röttgering, H. A. Holties, Y. Tang, Anna M. M. Scaife, Olaf Wucknitz, H. Munk, John D. Swinbank, Jean-Mathias Griessmeier, Vishambhar Pandey, Philip Best, Pim Schellart, T. Coenen, Kenneth C. Anderson, Kapteyn Astronomical Institute, Astronomy, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy (ASTRON), Max-Planck-Institut für Radioastronomie (MPIFR), Oxford Astrophysics, University of Oxford [Oxford], Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), University of Southampton, Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), University of Sheffield [Sheffield], Thüringer Landessternwarte Tautenburg (TLS), Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], Space Telescope Science Institute (STSci), School of Physics and Astronomy [Southampton], Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, University of Edinburgh, Jacobs University [Bremen], Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Leiden Observatory [Leiden], Universiteit Leiden [Leiden], National Radio Astronomy Observatory (NRAO), Applied Stochastics (IMAPP), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH / Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures (DSMZ), Center for Information Technology CIT, Université de Groningen, Netherlands Foundation for Scientific Research. Joeri van Leeuwen and ThijsCoenen are supported by the Netherlands Research School for Astronomy (GrantNOVA3-NW3-2.3.1), European Project: 224838,EC:FP7:PEOPLE,FP7-PEOPLE-2007-4-3-IRG,PULSARS WITH LOFAR(2008), European Project: 236394,EC:FP7:PEOPLE,FP7-PEOPLE-IEF-2008,PULSAR SURVEY(2010), Hassall, T.E., Stappers, B.W., Hessels, J.W.T., Kramer, M., Alexov, A., Anderson, K., Coenen, T., Karastergiou, A., Keane, E.F., Kondratiev, V.I., Lazaridis, K., Van Leeuwen, J., Noutsos, A., Serylak, M., Sobey, C., Verbiest, J.P.W., Weltevrede, P., Zagkouris, K., Fender, R., Wijers, R.A.M.J., Bähren, L., Bell, M.E., Broderick, J.W., Corbel, S., Daw, E.J., Dhillon, V.S., Eislöffel, J., Falcke, H., Grießmeier, J.-M., Jonker, P., Law, C., Markoff, S., Miller-Jones, J.C.A., Osten, R., Rol, E., Scaife, A.M.M., Scheers, B., Schellart, P., Spreeuw, H., Swinbank, J., Ter Veen, S., Wise, M.W., Wijnands, R., Wucknitz, O., Zarka, P., Asgekar, A., Bell, M.R., Bentum, M.J., Bernardi, G., Best, P., Bonafede, A., Boonstra, A.J., Brentjens, M., Brouw, W.N., Brüggen, M., Butcher, H.R., Ciardi, B., Garrett, M.A., Gerbers, M., Gunst, A.W., Van Haarlem, M.P., Heald, G., Hoeft, M., Holties, H., De Jong, A., Koopmans, L.V.E., Kuniyoshi, M., Kuper, G., Loose, G.M., Maat, P., Masters, J., McKean, J.P., Meulman, H., Mevius, M., Munk, H., Noordam, J.E., Orrú, E., Paas, H., Pandey-Pommier, M., Pandey, V.N., Pizzo, R., Polatidis, A., Reich, W., Röttgering, H., Sluman, J., Steinmetz, M., Sterks, C.G.M., Tagger, M., Tang, Y., Tasse, C., Vermeulen, R., Van Weeren, R.J., Wijnholds, S.J., Yatawatta, S., University of Oxford, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Radboud University [Nijmegen], Harvard University-Smithsonian Institution, Universiteit Leiden, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), High Energy Astrophys. & Astropart. Phys (API, FNWI), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Rhodes University, SKA South Africa, and Ska South Africa

Subjects
010504 meteorology & atmospheric sciences, Astronomy, Magnetosphere, Astrophysics, magnetic fields, 01 natural sciences, law.invention, law, Dispersion (optics), 010303 astronomy & astrophysics, Telescope, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [PHYS]Physics [physics], Astrophysics::Instrumentation and Methods for Astrophysics, SPECTRAL BEHAVIOR, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Astrophysics - High Energy Astrophysical Phenomena, ARRIVAL-TIME DELAY, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, SUPERDISPERSION DELAY, EMPIRICAL-THEORY, Pulsar, pulsars: general, 0103 physical sciences, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, ISM: general, METIS-287956, Gravitational wave, Astronomy and Astrophysics, telescopes, LOFAR, Astronomy and Astrophysic, EWI-22107, Pulse (physics), PULSES, Interstellar medium, PSR 0809&74, FREQUENCY-DEPENDENCE, Magnetic field, Space and Planetary Science, [SDU]Sciences of the Universe [physics], RADIO-EMISSION, IR-80985, REFRACTION, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], INTERSTELLAR SCATTERING
Abstract

Dispersion in the interstellar medium is a well known phenomenon that follows a simple relationship, which has been used to predict the time delay of dispersed radio pulses since the late 1960s. We performed wide-band simultaneous observations of four pulsars with LOFAR (at 40-190 MHz), the 76-m Lovell Telescope (at 1400 MHz) and the Effelsberg 100-m Telescope (at 8000 MHz) to test the accuracy of the dispersion law over a broad frequency range. In this paper we present the results of these observations which show that the dispersion law is accurate to better than 1 part in 100000 across our observing band. We use this fact to constrain some of the properties of the ISM along the line-of-sight and use the lack of any aberration or retardation effects to determine upper limits on emission heights in the pulsar magnetosphere. We also discuss the effect of pulse profile evolution on our observations, and the implications that it could have for precision pulsar timing projects such as the detection of gravitational waves with pulsar timing arrays., 20 Pages, 14 Figures, Accepted for publication in Astronomy & Astrophysics

Published
2012

36. Investigations of the radio signal of inclined showers with LOPES

Author

J. Wochele, Claus Grupen, Stijn Buitink, Octavian Sima, G.C. Trinchero, M. Finger, D. Heck, P. Luczak, Jörg R. Hörandel, N. Palmieri, H. Bozdog, H. J. Mathes, T. Pierog, C. Morello, L. Bähren, O. Krömer, Peter L. Biermann, S. Nehls, A. Chiavassa, F.G. Schröder, H. Gemmeke, D. Kang, M. Ludwig, Alexandra Saftoiu, A. Weindl, Jan Kuijpers, J. Rautenberg, D. Fuhrmann, T. Asch, M. Wommer, Kai Daumiller, Heino Falcke, V. de Souza, C. Rühle, Markus Roth, Tim Huege, D. Huber, J.C. Arteaga, J. Blümer, Peter Buchholz, I.M. Brancus, A. Schmidt, S.J. Lafebre, K. Bekk, E. Cantoni, Ralph Engel, P.G. Isar, W. D. Apel, K. Link, A. Haungs, J. Zabierowski, J. Oehlschläger, M. E. Bertaina, G. Toma, M. Melissas, J. A. Zensus, A. Horneffer, K. H. Kampert, H. Rebel, H. Schieler, and P. Doll

Subjects
Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Antenna aperture, Antenna measurement, Astrophysics::Instrumentation and Methods for Astrophysics, law.invention, Radiation pattern, Optics, law, Dipole antenna, Antenna (radio), Omnidirectional antenna, business, Instrumentation, Monopole antenna
Abstract

We report in this paper on an analysis of 20 months of data taken with LOPES. LOPES is radio antenna array set-up in coincidence with the Grande array, both located at the Karlsruhe Institute of Technology, Germany. The data used in this analysis were taken with an antenna configuration composed of 30 inverted V-shape dipole antennas. We have restricted the analysis to a special selection of inclined showers—with zenith angle θ > 40 ∘ . These inclined showers are of particular interest because they are the events with the largest geomagnetic angles and are therefore suitable to test emission models based on geomagnetic effects.The reconstruction procedure of the emitted radio signal in EAS uses as one ingredient the frequency-dependent antenna gain pattern which is obtained from simulations. Effects of the applied antenna model in the calibration procedure of LOPES are studied. In particular, we have focused on one component of the antenna, a metal pedestal, which generates a resonance effect, a peak in the amplification pattern where it is the most affecting high zenith angles, i.e. inclined showers. In addition, polarization characteristics of inclined showers were studied in detail and compared with the features of more vertical showers for the two cases of antenna models, with and without the pedestal.

Published
2012

37. On noise treatment in radio measurements of cosmic ray air showers

Author

Peter Buchholz, I.M. Brancus, G.C. Trinchero, A. Horneffer, T. Pierog, J. Blümer, S. Nehls, H. Bozdog, N. Palmieri, Claus Grupen, Jörg R. Hörandel, Stijn Buitink, A. Schmidt, E. Cantoni, C. Rühle, A. Weindl, Jan Kuijpers, K. Link, K. H. Kampert, A. Haungs, Markus Roth, J. A. Zensus, J. Zabierowski, S.J. Lafebre, J. Oehlschläger, Alexandra Saftoiu, H. J. Mathes, Ralph Engel, M. E. Bertaina, V. de Souza, P. Doll, F.G. Schröder, J. Wochele, G. Toma, Octavian Sima, M. Wommer, D. Fuhrmann, K. Bekk, D. Heck, M. Ludwig, W. D. Apel, T. Asch, H. Rebel, H. Schieler, Heino Falcke, A. Chiavassa, J. Rautenberg, Kai Daumiller, D. Huber, P. Luczak, J.C. Arteaga, D. Kang, L. Bähren, O. Krömer, P.G. Isar, C. Morello, Peter L. Biermann, M. Finger, H. Gemmeke, M. Melissas, and Tim Huege

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Field strength, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Atmospheric noise, Signal, Noise floor, Optics, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, business, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instrumentation, Cosmic noise, Noise (radio)
Abstract

Precise measurements of the radio emission by cosmic ray air showers require an adequate treatment of noise. Unlike to usual experiments in particle physics, where noise always adds to the signal, radio noise can in principle decrease or increase the signal if it interferes by chance destructively or constructively. Consequently, noise cannot simply be subtracted from the signal, and its influence on amplitude and time measurement of radio pulses must be studied with care. First, noise has to be determined consistently with the definition of the radio signal which typically is the maximum field strength of the radio pulse. Second, the average impact of noise on radio pulse measurements at individual antennas is studied for LOPES. It is shown that a correct treatment of noise is especially important at low signal-to-noise ratios: noise can be the dominant source of uncertainty for pulse height and time measurements, and it can systematically flatten the slope of lateral distributions. The presented method can also be transfered to other experiments in radio and acoustic detection of cosmic rays and neutrinos., 4 pages, 6 figures, submitted to NIM A, Proceedings of ARENA 2010, Nantes, France

Published
2012

38. Observing pulsars and fast transients with LOFAR

Author

S. ter Veen, A. W. Gunst, John D. Swinbank, T. Grit, R.-J. Dettmar, Sera Markoff, Patrick Weltevrede, M. A. Garrett, J. Sluman, Léon V. E. Koopmans, P. Maat, George Heald, John McKean, J. P. Hamaker, M. J. Norden, H. J. A. Röttgering, Sarod Yatawatta, V. S. Dhillon, Aris Karastergiou, J. D. Mol, A. Noutsos, M. P. van Haarlem, C. G. M. Sterks, Y. Tang, Casey J. Law, Stefan J. Wijnholds, Ashish Asgekar, Jason W. T. Hessels, Jochen Eislöffel, W. N. Brouw, A. van Duin, P. Bennema, M. Gerbers, J. W. Broderick, V. I. Kondratiev, P. C. Broekema, Michael W. Wise, Harvey Butcher, A. Alexov, James Miller-Jones, Oleg Smirnov, H. Spreeuw, L. Bähren, M. Loose, Joel N. Bregman, J. Noordam, A. G. de Bruyn, Philippe Zarka, R. Vermeulen, A. G. Polatidis, Marcus Brüggen, Heino Falcke, Kenneth C. Anderson, Matthias Hoeft, Matthias Steinmetz, A. Zensus, H. A. Holties, M. Pandey-Pommier, A. Schoenmakers, Olaf Wucknitz, Gerard H. Kuper, C. Vogt, Michael Kramer, Hans Olofsson, Bart Scheers, J. M. Anderson, N. J. Vermaas, Philip Best, T. E. Hassall, B. W. Stappers, D. McKay-Bukowski, R. Nijboer, Rob Fender, Ralph A. M. J. Wijers, T. Coenen, M. de Vos, George K. Miley, Mark J. Bentum, Rainer Beck, R. H. van de Brink, John Conway, Wolfgang Reich, Michel Tagger, E. J. Daw, Martin Bell, I. M. Avruch, B. Ciardi, A. Horneffer, John W. Romein, J. van Enst, Michiel A. Brentjens, J. van Leeuwen, J. M. Griessmeier, Raffaella Morganti, Kapteyn Astronomical Institute, Astronomy, Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], University of Amsterdam [Amsterdam] (UvA), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), Oxford Astrophysics, University of Oxford [Oxford], Netherlands Institute for Radio Astronomy (ASTRON), Max-Planck-Institut für Radioastronomie (MPIFR), University of Southampton, University of Sheffield [Sheffield], Thüringer Landessternwarte Tautenburg (TLS), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Observatoire de Paris - Site de Paris (OP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Jacobs University [Bremen], Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Astronomisches Institut der Ruhr-Universität Bochum, Ruhr-Universität Bochum [Bochum], Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Netherlands Research School for Astronomy (Grant NOVA3-NW3-2.3.1), European Project: 224838,EC:FP7:PEOPLE,FP7-PEOPLE-2007-4-3-IRG,PULSARS WITH LOFAR(2008), University of Oxford, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Radboud University [Nijmegen], Universiteit Leiden, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
DECAMETER WAVELENGTHS, Computer science, Astronomy, EWI-20531, INTENSITY VARIATIONS, 01 natural sciences, law.invention, FLUX DENSITIES, law, METIS-279184, instrumentation: interferometers, 010303 astronomy & astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Astrophysics::Instrumentation and Methods for Astrophysics, INTERSTELLAR PLASMA, Astrophysics - Solar and Stellar Astrophysics, LOW-FREQUENCY, Radio frequency, Ionosphere, methods: observational, Astrophysics - Instrumentation and Methods for Astrophysics, Radio astronomy, Radio wave, BINARY MILLISECOND PULSAR, GAMMA-RAY PULSARS, NEUTRON-STARS, Astrophysics::High Energy Astrophysical Phenomena, IR-78088, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, RADIO-CONTINUUM EMISSION, Radio telescope, Telescope, stars: neutron, Pulsar, pulsars: general, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), ISM: general, 010308 nuclear & particles physics, Radio window, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, telescopes, LOFAR, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Space and Planetary Science, DENSITY POWER SPECTRUM
Abstract

Low frequency radio waves, while challenging to observe, are a rich source of information about pulsars. The LOw Frequency ARray (LOFAR) is a new radio interferometer operating in the lowest 4 octaves of the ionospheric "radio window": 10-240MHz, that will greatly facilitate observing pulsars at low radio frequencies. Through the huge collecting area, long baselines, and flexible digital hardware, it is expected that LOFAR will revolutionize radio astronomy at the lowest frequencies visible from Earth. LOFAR is a next-generation radio telescope and a pathfinder to the Square Kilometre Array (SKA), in that it incorporates advanced multi-beaming techniques between thousands of individual elements. We discuss the motivation for low-frequency pulsar observations in general and the potential of LOFAR in addressing these science goals. We present LOFAR as it is designed to perform high-time-resolution observations of pulsars and other fast transients, and outline the various relevant observing modes and data reduction pipelines that are already or will soon be implemented to facilitate these observations. A number of results obtained from commissioning observations are presented to demonstrate the exciting potential of the telescope. This paper outlines the case for low frequency pulsar observations and is also intended to serve as a reference for upcoming pulsar/fast transient science papers with LOFAR., Comment: 35 pages, 19 figures, accepted for publication by A&A

Published
2011

39. The LOPES experiment

Author

A. Saftoiu, C. Grupen, Frank G. Schröder, J. A. Zensus, M. Finger, K. Bekk, P. Łuczak, Heino Falcke, Jörg R. Hörandel, D. Fuhrmann, N. Palmieri, M. Melissas, Dieter Heck, M. Wommer, L. Bähren, S.J. Lafebre, J. Oehlschläger, H. Bozdog, A. Horneffer, C. Morello, H. Rebel, P.G. Isar, Harald Schieler, J. Blümer, Katrin Link, D. Kang, M. Ludwig, Peter L. Biermann, C. Rühle, O. Krömer, V. de Souza, T. Asch, Karl-Heinz Kampert, H. Gemmeke, T. Pierog, W. D. Apel, Markus Roth, J. Rautenberg, D. Huber, S. Nehls, A. Weindl, A. Chiavassa, G.C. Trinchero, Jan Kuijpers, J.C. Arteaga, Andreas Haungs, G. Toma, P. Doll, Hermann-Josef Mathes, Kai Daumiller, Tim Huege, E. Cantoni, Ralph Engel, M. E. Bertaina, Stijn Buitink, A. Schmidt, Peter Buchholz, I.M. Brancus, J. Zabierowski, J. Wochele, and Octavian Sima

Subjects
Physics, Nuclear and High Energy Physics, LOPES, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Aetiology, screening and detection [ONCOL 5], Astrophysics::Cosmology and Extragalactic Astrophysics, LOFAR, Astrophysics, Electron, Polarization (waves), Atomic and Molecular Physics, and Optics, Particle detector, Computational physics, Magnetic field, Electric field
Abstract

Cosmic ray particles hit the Earthʼs atmosphere and induce extensive air showers (EAS). These EAS mainly consist of electrons and positrons that produce radio emission due to their interaction with the Earthʼs magnetic field. Measuring this radio emission is the purpose of the LOPES (LOFAR Prototype Station) experiment. LOPES is located at Campus North of the Karlsruhe Institute of Technology at the same site as the EAS particle detector KASCADE-Grande. Since the first measurements in 2003, LOPES was improved by various experimental setups and could establish the radio technique. By now, detailed studies of the measured radio signal are performed, like the behaviour of the lateral distribution or the polarization of the electric field. Furthermore, with LOPES the dependence of the radio pulse on properties of the incoming cosmic ray, like primary energy, primary mass, or incoming direction is investigated. In this article we describe the different LOPES setups, next we explain our standard analysis procedure and then we discuss some highlights of our recent results.

Published
2011

40. Measurement of radio emission from extensive air showers with LOPES

Author

H. J. Mathes, B. Mitrica, Heino Falcke, A. Nigl, Peter Buchholz, I.M. Brancus, E. Cantoni, T. Asch, F. Cossavella, W. D. Apel, J. Wochele, Octavian Sima, Jörg R. Hörandel, D. Heck, A. Weindl, Jan Kuijpers, T. Pierog, A. Schmidt, H. Rebel, C. Morello, M. Ludwig, Alexandra Saftoiu, Piera Luisa Ghia, S. Nehls, Moses Ender, Claus Grupen, Peter L. Biermann, S.J. Lafebre, Paula Gina Isar, D. Kang, O. Krömer, A. Chiavassa, M. Petcu, J. Rautenberg, D. Kickelbick, R. Engel, V. de Souza, G.C. Trinchero, M. Finger, H. Ulrich, R. Glasstetter, H. Gemmeke, T. Huege, P. Luczak, S. Over, M. Wommer, K. Bekk, M. Brüggemann, F. Di Pierro, M. Melissas, N. Palmieri, J. Oehlschläger, D. Fuhrmann, H. Bozdog, L. Bähren, Markus Roth, G. Navarra, Kai Daumiller, F. Badea, K. Link, A. Haungs, J. Zabierowski, Stijn Buitink, J. Blümer, H.J. Mayer, M. E. Bertaina, Frank G. Schröder, J.C. Arteaga, G. Toma, J. A. Zensus, A. Horneffer, K. H. Kampert, P. Doll, K. Singh, and H. Schieler

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nuclear and High Energy Physics, LOPES, business.industry, Physics::Instrumentation and Detectors, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Cosmic ray, Astrophysics, Aetiology, screening and detection [ONCOL 5], Shower, Air shower, Optics, Earth's magnetic field, Angle of incidence (optics), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Antenna (radio), business, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation, Radio wave
Abstract

A new method is explored to detect extensive air showers: the measurement of radio waves emitted during the propagation of the electromagnetic shower component in the magnetic field of the Earth. Recent results of the pioneering experiment LOPES are discussed. It registers radio signals in the frequency range between 40 and 80 MHz. The intensity of the measured radio emission is investigated as a function of different shower parameters, such as shower energy, angle of incidence, and distance to shower axis. In addition, new antenna types are developed in the framework of LOPES-Star and new methods are explored to realize a radio self-trigger algorithm in real time., Proc. RICAP 09, Nucl. Instr. and Meth. in press

Published
2011

41. LOFAR & HDF5: Toward a New Radio Data Standard

Author

G.A. Renting, K.R. Anderson, Michael W. Wise, L. Bähren, A. Alexov, and J.-M. Grießmeier

Subjects
Data Standard, Data products, Computer science, Spectral image, LOFAR, computer.file_format, Hierarchical Data Format, Data structure, Data science, computer, Encapsulation (networking)
Abstract

For decades now, scientific data volumes have experienced relentless, exponential growth. As a result, legacy astronomical data formats are straining under a burden not conceived when these formats were first introduced. With future astronomical projects ensuring this trend, ASTRON and the LOFAR project are exploring the use of the Hierarchical Data Format, version 5 (HDF5), for LOFAR radio data encapsulation. Most of LOFAR’s standard data products will be stored using the HDF5 format. In addition, HDF5 analogues for traditional radio data structures such as visibility data and spectral image cubes are also being developed. The HDF5 libraries allow for the construction of distributed, entirely unbounded files. The nature of the HDF5 format further provides the ability to custom design a data encapsulation format, specifying hierarchies, content and attributes. The LOFAR project has designed several data formats that will accommodate and house all LOFAR data products, the primary styles and kinds of which are presented in this paper. With proper development and support, it is hoped that these data formats will be adopted by other astronomical projects as they, too, attempt to grapple with a future filled with mountains of data.

Published
2010

42. The LOPES experiment - recent results, status and perspectives

Author

H. J. Mathes, G.C. Trinchero, F.G. Schröder, C. Morello, Kai Daumiller, J. Rautenberg, Peter L. Biermann, C. Rühle, Alexandra Saftoiu, D. Fuhrmann, H. Bozdog, J. Wochele, Markus Roth, Octavian Sima, M. Finger, T. Pierog, M. Ludwig, D. Heck, S. Nehls, M. Wommer, Jörg R. Hörandel, H. Gemmeke, Heino Falcke, J. Blümer, V. de Souza, Claus Grupen, A. Chiavassa, D. Kang, T. Asch, D. Huber, N. Palmieri, L. Bähren, J.C. Arteaga, O. Krömer, P. Luczak, A. Weindl, Jan Kuijpers, K. Bekk, Tim Huege, S.J. Lafebre, Peter Buchholz, I.M. Brancus, A. Schmidt, E. Cantoni, Ralph Engel, W. D. Apel, G. Toma, A. Horneffer, P. Doll, P.G. Isar, J. A. Zensus, H. Rebel, M. Melissas, H. Schieler, Karl-Heinz Kampert, K. Link, A. Haungs, J. Zabierowski, Stijn Buitink, J. Oehlschläger, and M. E. Bertaina

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Nuclear and High Energy Physics, LOPES, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Cosmic ray, Polarization (waves), Coincidence, Computational physics, Interferometry, Air shower, Earth's magnetic field, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation
Abstract

The LOPES experiment at the Karlsruhe Institute of Technology has been taking radio data in the frequency range from 40 to 80 MHz in coincidence with the KASCADE-Grande air shower detector since 2003. Various experimental configurations have been employed to study aspects such as the energy scaling, geomagnetic dependence, lateral distribution, and polarization of the radio emission from cosmic rays. The high quality per-event air shower information provided by KASCADE-Grande has been the key to many of these studies and has even allowed us to perform detailed per-event comparisons with simulations of the radio emission. In this article, we give an overview of results obtained by LOPES, and present the status and perspectives of the ever-evolving experiment., Proceedings of the ARENA2010 conference, Nantes, France

Published
2010

43. Measuring the radio emission of cosmic ray air showers with LOPES

Author

Claus Grupen, T. Pierog, A. Nigl, G.C. Trinchero, J. Wochele, Octavian Sima, L. Bähren, J. Blümer, N. Palmieri, F. Di Pierro, C. Morello, M. Wommer, O. Krömer, Piera Luisa Ghia, S. Nehls, M. Brüggemann, Peter L. Biermann, A. Weindl, Jan Kuijpers, A. Haungs, K. Bekk, Tim Huege, D. Heck, Jörg R. Hörandel, J. Zabierowski, Markus Roth, M. Finger, M. Ludwig, H. Bozdog, J.C. Arteaga, F. Badea, A. Chiavassa, M. Petcu, P. Doll, R. Glasstetter, D. Kickelbick, J. A. Zensus, Stijn Buitink, Peter Buchholz, M. Melissas, H.J. Mayer, V. de Souza, A. Horneffer, I.M. Brancus, P.G. Isar, J. Oehlschläger, B. Mitrica, P. Luczak, H. Rebel, K. Singh, Heino Falcke, Alexandra Saftoiu, H. J. Mathes, M. E. Bertaina, J. Rautenberg, D. Kang, S. Over, H. Gemmeke, D. Fuhrmann, E. Cantoni, H. Schieler, F. Cossavella, Karl-Heinz Kampert, G. Toma, F.G. Schröder, S.J. Lafebre, H. Ulrich, A. Schmidt, T. Asch, Ralph Engel, W. D. Apel, G. Navarra, and Kai Daumiller

Subjects
Physics, Nuclear and High Energy Physics, LOPES, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Charged particle, law.invention, Antenna array, Optics, Air shower, law, Dipole antenna, Ultra-high-energy cosmic ray, Antenna (radio), business, Instrumentation
Abstract

When ultra high energy cosmic rays hit the atmosphere, they produce a shower of millions of secondary particles. Thereby the charged particles in the shower emit a radio pulse whilst deflected in the Earth's magnetic field. LOPES is a digital antenna array measuring these radio pulses in the frequency range from 40 to 80 MHz. It is located at the site of and triggered by the air shower experiment KASCADE-Grande at Karlsruhe Institute of Technology (KIT), Germany. In its present configuration, it consists of 15 east–west-polarized and 15 north–south-polarized, absolutely calibrated short dipole antennas, as well as 10 LPDAs (with two channels each). Furthermore, it serves as a test bench for technological developments, like new antenna types or a radio-based self-triggering ( LOPES STAR ). To achieve a good angular reconstruction and to digitally form a beam into the arrival direction of the shower, it has a precise time calibration.

Published
2010

44. LOFAR - A new experiment to record radio emission from cosmic particles

Author

A. Horneffer, L. Bähren, Jan Kuijpers, S.J. Lafebre, Heino Falcke, K. Singh, A. Nigl, Jörg R. Hörandel, Stijn Buitink, Olaf Scholten, and KVI - Center for Advanced Radiation Technology

Subjects
Physics, Nuclear and High Energy Physics, COSMIC cancer database, LOPES, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astronomy, Astrophysics::Instrumentation and Methods for Astrophysics, Outer space, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, LOFAR, Astrophysics, SIMULATIONS, Atomic and Molecular Physics, and Optics, CODALEMA, KASCADE, Observatory, RAY AIR-SHOWERS, RADIATION, Neutrino, media_common
Abstract

At present, a new digital radio observatory is under construction in the Netherlands and in Europe, the Low Frequency Array (LOFAR) [1]. It is designed as a multi-sensor network to assist scientists in the fields of astronomy, geophysics, and agriculture. The main focus of the astronomy community is to observe the radio Universe in the frequency range from 30 to 240 MHz. The astronomical part of LOFAR is organized in several key science projects, namely: cosmology (the epoch of re-ionization), wide-field surveys, transient detection, cosmic magnetism, the sun, and cosmic rays. The aim of the latter is the detection of radio emission from particle cascades, originating from extremely high-energy particles from outer space. Two main lines of research are followed: (i) the measurement of radio emission from extensive air showers, generated by interactions of high-energy cosmic rays in the atmosphere and (ii) the detection of radio emission of particle cascades in the Moon, originating from ultra high-energy neutrinos and cosmic rays interacting with the lunar surface. The present article gives a short introduction to the key science project “cosmic rays”.

Published
2009

45. Detecting radio pulses from air showers

Author

J. Wochele, Alexandra Saftoiu, Octavian Sima, Jörg R. Hörandel, D. Heck, S. Over, D. Fuhrmann, R. Glasstetter, A. Chiavassa, Stijn Buitink, H.J. Mayer, E. Cantoni, J. Rautenberg, Y. Kolotaev, H. Bozdog, F. Di Pierro, Markus Roth, J. Blümer, M. Stümpert, C. Morello, A. Haungs, Peter L. Biermann, H. Ulrich, F. Badea, J. Zabierowski, F. Cossavella, G.C. Trinchero, O. Krömer, M. Finger, Paula Gina Isar, A. Nigl, K. H. Kampert, J. A. Zensus, Wolfgang Walkowiak, M. Wommer, M. Brüggemann, Tim Huege, M. E. Bertaina, K. Singh, J. Milke, L. Bähren, G. Toma, J.C. Arteaga, A. Schmidt, H. Gemmeke, H. Schieler, A. Horneffer, T. Asch, W. D. Apel, R. Engel, P. Doll, A. Weindl, Jan Kuijpers, H. Rebel, P. Luczak, J. Oehlschläger, Claus Grupen, J. Auffenberg, Peter Buchholz, D. Kang, I.M. Brancus, D. Kickelbick, V. de Souza, M. Petcu, T. Pierog, Piera Luisa Ghia, S. Nehls, H. J. Mathes, F.G. Schröder, B. Mitrica, Heino Falcke, K. Bekk, S.J. Lafebre, G. Navarra, and Kai Daumiller

Subjects
Physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Astrophysics, Ground level, Atmospheric measurements, Air shower, Fluorescent light, Cascade, Physics::Atmospheric and Oceanic Physics, Optical observation, Cherenkov radiation
Abstract

Cosmic rays are energetic particles from outside the earth’s atmosphere. When a high energy cosmic ray hits the atmosphere it triggers a cascade of secondary particles produced in nuclear interactions, an air shower. Up to now the established methods of measuring air showers are detection of the particles that reach the ground level or optical observation of the Cherenkov or fluorescent light.

Published
2008

46. Cosmic Ray Air Shower Detection with LOPES

Author

J. Rautenberg, M. E. Bertaina, A. Hakenjos, J. Milke, Y. Kolotaev, W. D. Apel, K. H. Kampert, Markus Roth, A. Haungs, A. Horneffer, F. Di Pierro, Peter Buchholz, G.C. Trinchero, J. Blümer, I.M. Brancus, H. Ulrich, J. Zabierowski, C. Morello, O. Krömer, A. Nigl, R. Engel, P. Doll, Peter L. Biermann, Wolfgang Walkowiak, A.F. Badea, T. Pierog, Piera Luisa Ghia, T. Asch, S. Nehls, J. Petrovic, M. Brüggemann, J. Wochele, P. Luczak, Octavian Sima, Stijn Buitink, B. Mitrica, Heino Falcke, S.J. Lafebre, K. Singh, H.J. Mayer, J. A. Zensus, A. Chiavassa, S. Over, D. Heck, H. Gemmeke, Paula Gina Isar, A. Weindl, Jan Kuijpers, M. Stümpert, H. Rebel, Harvey Butcher, H. Bozdog, M. Petcu, C. Meurer, H. Schieler, J.R. Hörandel, Claus Grupen, L. Bähren, D. Zimmermann, J.C. Arteaga, G. Toma, H. J. Mathes, R. Glasstetter, J. Oehlschläger, S. Ostapchenko, K. Bekk, S. Plewnia, F. Cossavella, Kai Daumiller, T. Huege, G. Navarra, and J. van Buren

Subjects
Pierre Auger Observatory, Physics, Nuclear and High Energy Physics, Shower, Air shower, LOPES, Astronomy, Cosmic ray, Astrophysics, Atomic and Molecular Physics, and Optics, Absolute calibration
Abstract

LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to investigate radio pulses from extensive air showers experimentally and theoretically. Data taken during half a year of operation of 10 LOPES antennas (LOPES-10), triggered by EAS observed with KASCADE-Grande have been analysed. We report about the results of correlations with shower parameters present in the radio signals measured by LOPES-10. The extended setup LOPES-30 consists of 30 antennas which have an absolute calibration and the data of which will be compared with expectations from detailed Monte-Carlo simulations. In addition, LOPES operates antennas of a different type (LOPES STAR ) which are optimized for an application at the Pierre Auger Observatory.

Published
2008

47. Frequency spectra of cosmic ray air shower radio emission measured with LOPES

Author

A. Nigl, W. D. Apel, J. C. Arteaga, T. Asch, J. Auffenberg, F. Badea, L. Bähren, K. Bekk, M. Bertaina, P. L. Biermann, J. Blümer, H. Bozdog, I. M. Brancus, M. Brüggemann, P. Buchholz, S. Buitink, H. Butcher, E. Cantoni, A. Chiavassa, F. Cossavella, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, R. Engel, H. Falcke, H. Gemmeke, P. L. Ghia, R. Glasstetter, C. Grupen, A. Haungs, D. Heck, J. R. Hörandel, A. Horneffer, T. Huege, P. G. Isar, K.-H. Kampert, D. Kickelbick, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, P. Łuczak, M. Manewald, H. J. Mathes, H. J. Mayer, C. Meurer, B. Mitrica, C. Morello, G. Navarra, S. Nehls, J. Oehlschläger, S. Ostapchenko, S. Over, M. Petcu, T. Pierog, J. Rautenberg, H. Rebel, M. Roth, A. Saftoiu, H. Schieler, A. Schmidt, F. Schröder, O. Sima, K. Singh, M. Stümpert, G. Toma, G. C. Trinchero, H. Ulrich, J. van Buren, W. Walkowiak, A. Weindl, J. Wochele, J. Zabierowski, and J. A. Zensus

Subjects
Physics, LOPES, Frequency band, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, LOFAR, Astrophysics::Cosmology and Extragalactic Astrophysics, Spectral line, Air shower, KASCADE, Space and Planetary Science, Spectral slope
Abstract

AIMS: We wish to study the spectral dependence of the radio emission from cosmic-ray air showers around 100 PeV (1017 eV). METHODS: We observe short radio pulses in a broad frequency band with the dipole-interferometer LOPES (LOFAR Prototype Station), which is triggered by a particle detector array named Karlsruhe Shower Core and Array Detector (KASCADE). LOFAR is the Low Frequency Array. For this analysis, 23 strong air shower events are selected using parameters from KASCADE. RESULTS: The resulting electric field spectra fall off to higher frequencies. An average electric field spectrum is fitted with an exponential, or alternatively, with a power law. The spectral slope obtained is not consistent within uncertainties and it is slightly steeper than the slope obtained from Monte Carlo simulations based on air showers simulated with CORSIKA (Cosmic Ray Simulations for KASCADE). One of the strongest events was measured during thunderstorm activity in the vicinity of LOPES and shows the longest pulse length measured of 110 ns and a spectral slope of -3.6. CONCLUSIONS: We show with two different methods that frequency spectra from air shower radio emission can be reconstructed on event-by-event basis, with only two dozen dipole antennae simultaneously over a broad range of frequencies. According to the obtained spectral slopes, the maximum power is emitted below 40 MHz. Furthermore, the decrease in power to higher frequencies indicates a loss in coherence determined by the shower disc thickness. We conclude that a broader bandwidth, larger collecting area, and longer baselines, as will be provided by LOFAR, are necessary to further investigate the relation of the coherence, pulse length, and spectral slope of cosmic ray air showers., Comment: 13 pages, 21 figures. Nigl, A. et al. (LOPES Collaboration), Frequency spectra of cosmic ray air shower radio emission measured with LOPES, accepted by A&A on 17/06/2008

Published
2008

48. Direction identification in radio images of cosmic-ray air showers detected with LOPES and KASCADE

Author

A. Nigl, W. D. Apel, J. C. Arteaga, T. Asch, J. Auffenberg, F. Badea, L. Bähren, K. Bekk, M. Bertaina, P. L. Biermann, J. Blümer, H. Bozdog, I. M. Brancus, M. Brüggemann, P. Buchholz, S. Buitink, H. Butcher, E. Cantoni, A. Chiavassa, F. Cossavella, K. Daumiller, V. de Souza, F. Di Pierro, P. Doll, R. Engel, H. Falcke, H. Gemmeke, P. L. Ghia, R. Glasstetter, C. Grupen, A. Haungs, D. Heck, J. R. Hörandel, A. Horneffer, T. Huege, P. G. Isar, K.-H. Kampert, D. Kickelbick, Y. Kolotaev, O. Krömer, J. Kuijpers, S. Lafebre, P. Łuczak, M. Manewald, H. J. Mathes, H. J. Mayer, C. Meurer, B. Mitrica, C. Morello, G. Navarra, S. Nehls, J. Oehlschläger, S. Ostapchenko, S. Over, M. Petcu, T. Pierog, J. Rautenberg, H. Rebel, M. Roth, A. Saftoiu, H. Schieler, A. Schmidt, F. Schröder, O. Sima, K. Singh, M. Stümpert, G. Toma, G. C. Trinchero, H. Ulrich, J. van Buren, W. Walkowiak, A. Weindl, J. Wochele, J. Zabierowski, and J. A. Zensus

Subjects
Physics, LOPES, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Radius, Astrophysics::Cosmology and Extragalactic Astrophysics, Curvature, Particle detector, Air shower, KASCADE, Space and Planetary Science, Angular resolution
Abstract

AIMS: We want to understand the emission mechanism of radio emission from air showers to determine the origin of high-energy cosmic rays. Therefore, we study the geometry of the air shower radio emission measured with LOPES and search for systematic effects between the direction determined on the radio signal and the direction provided by the particle detector array KASCADE. METHODS: We produce 4D radio images on time-scales of nanoseconds using digital beam-forming. Each pixel of the image is calculated for three spatial dimensions and as a function of time. The third spatial dimension is obtained by calculating the beam focus for a range of curvature radii fitted to the signal wave front. We search this multi-dimensional parameter space for the direction of maximum coherence of the air shower radio signal and compare it to the direction provided by KASCADE. RESULTS: The maximum radio emission of air showers is obtained for curvature radii being larger than 3 km. We find that the direction of the emission maximum can change when optimizing the curvature radius. Furthermore, we find a tentative increase of the curvature radius to lower elevations, where the air showers pass through a larger atmospheric depth. CONCLUSIONS: We conclude that the angular resolution of LOPES is sufficient to determine the direction which maximizes the observed electric field amplitude. However, the statistical uncertainty of the directions is not determined by the resolution of LOPES, but by the uncertainty of the curvature radius. We do not find any systematic deviation between the directions determined from the radio signal and from the detected particles. This result places a strong supportive argument for the use of the radio technique to study the origin of high-energy cosmic rays., Comment: 8 pages, 13 figures. Nigl, A. et al. (LOPES Collaboration), Direction identification in radio images of cosmic rays detected with LOPES and KASCADE, accepted by A&A on 12/06/2008

Published
2008

49. Radio emission in atmospheric air showers: Results of LOPES-10

Author

A Haungs, W D Apel, T Asch, F Badea, L Bähren, K Bekk, A Bercuci, M Bertaina, P L Biermann, J Blümer, H Bozdog, I M Brancus, M Brüggemann, P Buchholz, S Buitink, H Butcher, A Chiavassa, F Cossavella, K Daumiller, F Di Pierro, P Doll, R Engel, H Falcke, H Gemmeke, P L Ghia, R Glasstetter, C Grupen, A Hakenjos, D Heck, J R Hörandel, A Horneffer, T Huege, P G Isar, K H Kampert, Y Kolotaev, O Krömer, J Kuijpers, S Lafebre, H J Mathes, H J Mayer, C Meurer, J Milke, B Mitrica, C Morello, G Navarra, S Nehls, A Nigl, R Obenland, J Oehlschläger, S Ostapchenko, S Over, M Petcu, J Petrovic, T Pierog, S Plewnia, H Rebel, A Risse, M Roth, H Schieler, O Sima, K Singh, M Stümpert, G Toma, G C Trinchero, H Ulrich, J van Buren, W Walkowiak, A Weindl, J Wochele, J Zabierowski, J A Zensus, and D Zimmermann

Subjects
Atmospheric air, Physics, History, Meteorology, LOPES, Astronomy, Astrophysics (astro-ph), Measure (physics), FOS: Physical sciences, Astrophysics, Computer Science Applications, Education, Shower, Air shower
Abstract

LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. Data taken during half a year of operation of 10 LOPES antennas (LOPES-10), triggered by showers observed with KASCADE-Grande have been analyzed. We report about results of correlations found of the measured radio signals by LOPES-10 with shower parameters., Comment: Proceedings of ARENA 06, June 2006, University of Northumbria, UK

Published
2007

50. Radio Emission in Atmospheric Air Showers: First Measurements with LOPES-30

Author

P G Isar, S Nehls, W D Apel, T Asch, F Badea, L Bähren, K Bekk, A Bercuci, M Bertaina, P L Biermann, J Blümer, H Bozdog, I M Brancus, M Brüggemann, P Buchholz, S Buitink, H Butcher, A Chiavassa, F Cossavella, K Daumiller, F Di Pierro, P Doll, R Engel, H Falcke, H Gemmeke, P L Ghia, R Glasstetter, C Grupen, A Hakenjos, A Haungs, D Heck, J R Hörandel, A Horneffer, T Huege, K H Kampert, Y Kolotaev, O Krömer, J Kuijpers, S Lafebre, H J Mathes, H J Mayer, C Meurer, J Milke, B Mitrica, C Morello, G Navarra, A Nigl, R Obenland, J Oehlschläger, S Ostapchenko, S Over, M Petcu, J Petrovic, T Pierog, S Plewnia, H Rebel, A Risse, M Roth, H Schieler, O Sima, K Singh, M Stümpert, G Toma, G C Trinchero, H Ulrich, J van Buren, W Walkowiak, A Weindl, J Wochele, J Zabierowski, J A Zensus, and D Zimmermann

Subjects
Atmospheric air, Physics, History, LOPES, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics, Computer Science Applications, Education, law.invention, Atmosphere, Shower, Air shower, law, Ultra-high-energy cosmic ray, Dipole antenna
Abstract

When Ultra High Energy Cosmic Rays interact with particles in the Earth's atmosphere, they produce a shower of secondary particles propagating toward the ground. LOPES-30 is an absolutely calibrated array of 30 dipole antennas investigating the radio emission from these showers in detail and clarifying if the technique is useful for largescale applications. LOPES-30 is co-located and measures in coincidence with the air shower experiment KASCADE-Grande. Status of LOPES-30 and first measurements are presented., Comment: Proceedings of ARENA 06, June 2006, University of Northumbria, UK

Published
2007

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