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Low-Frequency Imaging of Fields at High Galactic Latitude with the Murchison Widefield Array 32 Element Prototype
journal contribution
posted on 2023-05-17, 16:21 authored by Williams, CL, Hewitt, JN, Levine, AM, de Oliveira-Costa, A, Bowman, JD, Briggs, FH, Gaensler, BM, Hernquist, LL, Mitchell, DA, Morales, MF, Sethi, SK, Subrahmanyan, R, Sadler, EM, Arcus, W, Barnes, DG, Bernardi, G, Bunton, JD, Cappallo, RC, Crosse, BW, Corey, BE, Deshpande, A, deSouza, L, Emrich, D, Goeke, RF, Greenhill, LJ, Hazelton, BJ, Herne, D, Kaplan, DL, Kasper, JC, Kincaid, BB, Koenig, R, Kratzenberg, E, Lonsdale, CJ, Lynch, MJ, McWhirter, SR, Morgan, EH, Oberoi, D, Ord, SM, Pathikulangara, J, Prabu, T, Remillard, RA, Rogers, AEE, Roshi, DA, Salah, JE, Sault, RJ, Shankar, NU, Srivani, KS, Stevens, JB, Tingay, SJ, Wayth, RB, Waterson, M, Webster, RL, Whitney, AR, Williams, AJ, Wyithe, JSBThe 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 110-200 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.
History
Publication title
The Astrophysical JournalVolume
755Article number
47Number
47Pagination
1-19ISSN
0004-637XDepartment/School
School of Natural SciencesPublisher
IOP SciencePlace of publication
1427 E 60Th St, Chicago, USA, Il, 60637-2954Rights statement
Copyright 2012 The American Astronomical SocietyRepository Status
- Restricted