LOW-FREQUENCY IMAGING OF FIELDS AT HIGH GALACTIC LATITUDE WITH THE MURCHISON WIDEFIELD ARRAY 32 ELEMENT PROTOTYPE

Journal Article · Fri Aug 10 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/755/1/47· OSTI ID:22039148

Williams, Christopher L; Hewitt, Jacqueline N; Levine, Alan M ^[1]; De Oliveira-Costa, Angelica; Hernquist, Lars L; Bernardi, Gianni ^[2]; Bowman, Judd D ^[3]; Briggs, Frank H ^[4]; Gaensler, B M; Mitchell, Daniel A; Subrahmanyan, Ravi; Sadler, Elaine M ^[5]; Morales, Miguel F ^[6]; Sethi, Shiv K ^[7]; Arcus, Wayne; Crosse, Brian W ^[8]; Barnes, David G ^[9]; Bunton, John D ^[10]; Cappallo, Roger C; others, and

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1. MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA (United States)
2. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
3. School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States)
4. Research School of Astronomy and Astrophysics, The Australian National University, Canberra (Australia)
5. ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia)
6. Department of Physics, University of Washington, Seattle, WA (United States)
7. Raman Research Institute, Bangalore (India)
8. International Centre for Radio Astronomy Research, Curtin University, Perth (Australia)
9. Center for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne (Australia)
10. CSIRO Astronomy and Space Science, Epping (Australia)

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 Degree-Sign diameter fields in the southern sky, covering a total of {approx}2700 deg{sup 2}, 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 {approx}15' angular resolution maps of the two fields in the 110-200 MHz 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 110-200 MHz band.

• OSTI ID: 22039148
• Journal Information: Astrophysical Journal, Vol. 755, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALGORITHMS
ASTROPHYSICS
CALIBRATION
CATALOGS
COMPARATIVE EVALUATIONS
DATA ANALYSIS
IMAGES
INTERFEROMETERS
MHZ RANGE
NORTHERN HEMISPHERE
PERFORMANCE
POINT SOURCES
RADIOASTRONOMY
RESOLUTION
SKY
STARS