Abstract
The Murchison Widefield Array (MWA) is a new low-frequency, wide-field-of-view radio interferometer under development at the Murchison Radio-astronomy Observatory in Western Australia. We have used a 32 element MWA prototype interferometer (MWA-32T) to observe two 50° diameter fields in the southern sky, covering a total of 2700 deg2, 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 in the 110-200MHz band. 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 110-200MHz band.
Original language | English (US) |
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Article number | 47 |
Journal | Astrophysical Journal |
Volume | 755 |
Issue number | 1 |
DOIs | |
State | Published - Aug 10 2012 |
Keywords
- dark ages
- first stars
- instrumentation: interferometers
- methods: data analysis
- reionization
- surveys
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science