A search for ultrahigh-energy neutrinos and measurement of cosmic ray radio emission with the Antarctic Impulsive Transient Antenna

New astronomical messengers may reveal unexpected aspects of the Universe and have often provided a unique source of fresh physical insights. Neutrinos are a promising new messenger particle, capable of carrying information from otherwise inaccessible sources. The ANtarctic Impulsive Transient Antenna (ANITA) seeks to make the first detection of an ultrahigh-energy (E > 1018 eV) neutrino flux. Such a neutrino flux almost certainly exists, produced in interactions of ultrahigh-energy cosmic rays with photons from the cosmic microwave background. ANITA is a balloon payload which monitors large volumes of the Antarctic ice sheet from an altitude of 38 km. An ultrahigh-energy neutrino which interacts in the ice sheet will produce a particle shower which will coherently radiate Cherenkov radiation in radio wavelengths (<3 GHz). Antennas on the balloon payload can then detect the resulting impulsive radio signal.;The full ANITA flew for the first time from 15 December 2006 to 19 January 2007. In this dissertation, I will describe the ground calibration system used to transmit calibration signals to the payload in-flight. I will then describe techniques for analysis of ANITA data and give limits on the ultrahigh-energy neutrino flux implied by the null result of that analysis. Finally, I will demonstrate that ANITA is also sensitive to ultrahigh-energy cosmic rays and show the detection of 16 ultrahigh-energy cosmic-ray events during ANITA's first flight. This constitutes the highest frequency and widest bandwidth radio observations of cosmic-ray emission to date I show the average waveform and spectrum of these events and describe their polarization properties, which are strongly correlated with the geomagnetic field.