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) |
|---|---|
| Article number | 47 |
| Journal | Astrophysical Journal |
| Volume | 755 |
| Issue number | 1 |
| DOIs | |
| State | Published - Aug 10 2012 |
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Keywords
- dark ages
- first stars
- instrumentation: interferometers
- methods: data analysis
- reionization
- surveys
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Low-frequency imaging of fields at high galactic latitude with the murchison widefield Array 32 element prototype. / Williams, Christopher L.; Hewitt, Jacqueline N.; Levine, Alan M.; De Oliveira-Costa, Angelica; Bowman, Judd; Briggs, Frank H.; Gaensler, B. M.; Hernquist, Lars L.; Mitchell, Daniel A.; Morales, Miguel F.; Sethi, Shiv K.; Subrahmanyan, Ravi; Sadler, Elaine M.; Arcus, Wayne; Barnes, David G.; Bernardi, Gianni; Bunton, John D.; Cappallo, Roger C.; Crosse, Brian W.; Corey, Brian E.; Deshpande, Avinash; Desouza, Ludi; Emrich, David; Goeke, Robert F.; Greenhill, Lincoln J.; Hazelton, Bryna J.; Herne, David; Kaplan, David L.; Kasper, Justin C.; Kincaid, Barton B.; Koenig, Ronald; Kratzenberg, Eric; Lonsdale, Colin J.; Lynch, Mervyn J.; McWhirter, S. Russell; Morgan, Edward H.; Oberoi, Divya; Ord, Stephen M.; Pathikulangara, Joseph; Prabu, Thiagaraj; Remillard, Ronald A.; Rogers, Alan E E; Roshi, D. Anish; Salah, Joseph E.; Sault, Robert J.; Shankar, N. Udaya; Srivani, K. S.; Stevens, Jamie B.; Tingay, Steven J.; Wayth, Randall B.; Waterson, Mark; Webster, Rachel L.; Whitney, Alan R.; Williams, Andrew J.; Wyithe, J. Stuart B.
In: Astrophysical Journal, Vol. 755, No. 1, 47, 10.08.2012.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Low-frequency imaging of fields at high galactic latitude with the murchison widefield Array 32 element prototype
AU - Williams, Christopher L.
AU - Hewitt, Jacqueline N.
AU - Levine, Alan M.
AU - De Oliveira-Costa, Angelica
AU - Bowman, Judd
AU - Briggs, Frank H.
AU - Gaensler, B. M.
AU - Hernquist, Lars L.
AU - Mitchell, Daniel A.
AU - Morales, Miguel F.
AU - Sethi, Shiv K.
AU - Subrahmanyan, Ravi
AU - Sadler, Elaine M.
AU - Arcus, Wayne
AU - Barnes, David G.
AU - Bernardi, Gianni
AU - Bunton, John D.
AU - Cappallo, Roger C.
AU - Crosse, Brian W.
AU - Corey, Brian E.
AU - Deshpande, Avinash
AU - Desouza, Ludi
AU - Emrich, David
AU - Goeke, Robert F.
AU - Greenhill, Lincoln J.
AU - Hazelton, Bryna J.
AU - Herne, David
AU - Kaplan, David L.
AU - Kasper, Justin C.
AU - Kincaid, Barton B.
AU - Koenig, Ronald
AU - Kratzenberg, Eric
AU - Lonsdale, Colin J.
AU - Lynch, Mervyn J.
AU - McWhirter, S. Russell
AU - Morgan, Edward H.
AU - Oberoi, Divya
AU - Ord, Stephen M.
AU - Pathikulangara, Joseph
AU - Prabu, Thiagaraj
AU - Remillard, Ronald A.
AU - Rogers, Alan E E
AU - Roshi, D. Anish
AU - Salah, Joseph E.
AU - Sault, Robert J.
AU - Shankar, N. Udaya
AU - Srivani, K. S.
AU - Stevens, Jamie B.
AU - Tingay, Steven J.
AU - Wayth, Randall B.
AU - Waterson, Mark
AU - Webster, Rachel L.
AU - Whitney, Alan R.
AU - Williams, Andrew J.
AU - Wyithe, J. Stuart B
PY - 2012/8/10
Y1 - 2012/8/10
N2 - 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.
AB - 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.
KW - dark ages
KW - first stars
KW - instrumentation: interferometers
KW - methods: data analysis
KW - reionization
KW - surveys
UR - http://www.scopus.com/inward/record.url?scp=84864429378&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84864429378&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/755/1/47
DO - 10.1088/0004-637X/755/1/47
M3 - Article
AN - SCOPUS:84864429378
VL - 755
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 47
ER -