Coherent Radiation from Extensive Air Showers in the Ultra-High Frequency Band

Abstract

Using detailed Monte Carlo simulations we have characterized the features of the radio emission of inclined air showers in the Ultra-High Frequency band (300 MHz - 3 GHz). The Fourier-spectrum of the radiation is shown to have a sizable intensity well into the GHz frequency range. The emission is mainly due to transverse currents induced by the geomagnetic field and to the excess charge produced by the Askaryan effect. At these frequencies only a significantly reduced volume of the shower around the axis contributes coherently to the signal observed on the ground. The size of the coherently emitting volume depends on frequency, shower geometry and observer position, and is interpreted in terms of the relative time delays. At ground level, the maximum emission at high frequencies is concentrated in an elliptical ring-like region around the intersection of a Cherenkov cone with its vertex at shower maximum and the ground. The frequency spectrum of inclined showers when observed at positions that view shower maximum in the Cherenkov direction, is shown to be in broad agreement with the pulses detected by the Antarctic Impulsive Transient Antenna (ANITA) experiment, making the interpretation that they are due to Ultra-High Energy Cosmic Ray atmospheric showers consistent with our simulations. These results are also of great importance for experiments aiming to detect molecular bremsstrahlung radiation in the GHz range as they present an important background for its detection.

8 pages, 8 figures

References in corpus (11)

• The Antarctic Impulsive Transient Antenna Ultra-high Energy Neutrino Detector Design, Performance, and Sensitivity for 2006-2007 Balloon Flight
• A Macroscopic Description of Coherent Geo-Magnetic Radiation from Cosmic Ray Air Showers
• A Realistic Treatment of Geomagnetic Cherenkov Radiation from Cosmic Ray Air Showers
• REAS3: Monte Carlo simulations of radio emission from cosmic ray air showers using an "end-point" formalism
• Macroscopic Treatment of Radio Emission from Cosmic Ray Air Showers based on Shower Simulations
• The Lateral Distribution Function of Coherent Radio Emission from Extensive Air Showers; Determining the Chemical Composition of Cosmic Rays
• Simulation of radio emission from cosmic ray air shower with SELFAS2
• Observations of Microwave Continuum Emission from Air Shower Plasmas
• Frequency spectra of cosmic ray air shower radio emission measured with LOPES
• Detection of elusive Radio and Optical emission from Cosmic-ray showers in the 1960s
• Search for microwave emission from ultrahigh energy cosmic rays

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• Energy and Flux Measurements of Ultra-High Energy Cosmic Rays Observed During the First ANITA Flight
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• Observation of inclined EeV air showers with the radio detector of the Pierre Auger Observatory
• A comprehensive analysis of anomalous ANITA events disfavors a diffuse tau-neutrino flux origin
• Tau Neutrinos in the Next Decade: from GeV to EeV
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• The Giant Radio Array for Neutrino Detection
• The Giant Radio Array for Neutrino Detection (GRAND): Present and Perspectives
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• Molecular Bremsstrahlung Radiation at GHz Frequencies in Air
• Density and magnetic intensity dependence of radio pulses induced by energetic air showers
• Determination of cosmic-ray primary mass on an event-by-event basis using radio detection
• Characterization of Atmosphere-Skimming Cosmic-Ray Showers in High-Altitude Experiments
• On the coherent emission of radio frequency radiation from high energy particle showers
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• Considerations on the radio emission from extended air showers