The Allen Telescope Array Fly's Eye survey for fast radio transients

Abstract

The relatively unexplored fast radio transient parameter space is known to be home to a variety of interesting sources, including pulsars, pulsar giant pulses, and non-thermal emission from planetary magnetospheres. In addition, a variety of hypothesized but as-yet-unobserved phenomena such as primordial black hole evaporation and prompt emission associated with coalescing massive objects have been suggested. The 2007 announcement by Lorimer et al. of the detection of a bright (30Jy) radio pulse that was inferred to be of extragalactic origin and the subsequent consternation have demonstrated both the need for wide-field surveys characterizing the fast-transient parameter space and the potential utility of bright radio pulses as probes of the interstellar medium and intergalactic medium. Here we present results from the 450hr, 150deg2 Fly's Eye survey for bright dispersed radio pulses at the Allen Telescope Array (ATA). The Fly's Eye Spectrometer produces 128 channel power spectra over a 209MHz bandwidth, centered at 1430MHz, on 44 independent signal paths originating with 30 independent ATA antennae. Data were dedispersed between 0 and 2000pccm-3 and searched for pulses with dispersion measures greater than 50pccm-3 between 625 μs and 5s in duration. No pulses were detected in the survey, implying a limiting rate of less than 2sky -1hr-1 for 10ms duration pulses having apparent energy densities greater than 440kJy μs, or mean flux densities greater than 44Jy. Here we present details of the instrument, experiment, and observations, including a discussion of our results in light of other single pulse searches. © 2012. The American Astronomical Society. All rights reserved.