Observation of Ultrahigh-Energy Cosmic Rays with the ANITA Balloon-Borne Radio Interferometer
We report the observation of 16 cosmic ray events with a mean energy of 1: 5 x 10(19) eV via radio pulses originating from the interaction of the cosmic ray air shower with the Antarctic geomagnetic field, a process known as geosynchrotron emission. We present measurements in the 300-900 MHz range,...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
AMER PHYSICAL SOC
2010
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Subjects: | |
Online Access: | https://discovery.ucl.ac.uk/id/eprint/408812/1/408812.pdf https://discovery.ucl.ac.uk/id/eprint/408812/ |
Summary: | We report the observation of 16 cosmic ray events with a mean energy of 1: 5 x 10(19) eV via radio pulses originating from the interaction of the cosmic ray air shower with the Antarctic geomagnetic field, a process known as geosynchrotron emission. We present measurements in the 300-900 MHz range, which are the first self-triggered, first ultrawide band, first far-field, and the highest energy sample of cosmic ray events collected with the radio technique. Their properties are inconsistent with current ground-based geosynchrotron models. The emission is 100% polarized in the plane perpendicular to the projected geomagnetic field. Fourteen events are seen to have a phase inversion due to reflection of the radio beam off the ice surface, and two additional events are seen directly from above the horizon. Based on a likelihood analysis, we estimate angular pointing precision of order 2 degrees for the event arrival directions. |
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