Low Frequency Imaging of Fields at High Galactic Latitude with the
  Murchison Widefield Array 32-Element Prototype
  The Murchison Widefield Array (MWA) is a new low-frequency, wide
field-of-view radio interferometer under development at the Murchison
Radio-astronomy Observatory (MRO) in Western Australia. We have used a
32-element MWA prototype interferometer (MWA-32T) to observe two 50-degree
diameter fields in the southern sky in the 110 MHz to 200 MHz band in order to
evaluate the performance of the MWA-32T, to develop techniques for epoch of
reionization experiments, and to make measurements of astronomical foregrounds.
We developed a calibration and imaging pipeline for the MWA-32T, and used it to
produce ~15' angular resolution maps of the two fields. We perform a blind
source extraction using these confusion-limited images, and detect 655 sources
at high significance with an additional 871 lower significance source
candidates. We compare these sources with existing low-frequency radio surveys
in order to assess the MWA-32T system performance, wide field analysis
algorithms, and catalog quality. Our source catalog is found to agree well with
existing low-frequency surveys in these regions of the sky and with statistical
distributions of point sources derived from Northern Hemisphere surveys; it
represents one of the deepest surveys to date of this sky field in the 110 MHz
to 200 MHz band.
