Low Frequency Imaging of Fields at High Galactic Latitude with the Murchison Widefield Array 32-Element Prototype
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 (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.
Keywords
Cite
@article{arxiv.1203.5790,
title = {Low Frequency Imaging of Fields at High Galactic Latitude with the Murchison Widefield Array 32-Element Prototype},
author = {Christopher L. Williams and Jacqueline N. Hewitt and Alan M. Levine and Angelica de Oliveira-Costa and Judd D. Bowman and Frank H. Briggs and B. M. Gaensler and Lars L. Hernquist and Daniel A. Mitchell and Miguel F. Morales and Shiv K. Sethi and Ravi Subrahmanyan and Elaine M. Sadler and Wayne Arcus and David G. Barnes and Gianni Bernardi and John D. Bunton and Roger C. Cappallo and Brian W. Crosse and Brian E. Corey and Avinash Deshpande and Ludi deSouza and David Emrich and Robert F. Goeke and Lincoln J. Greenhill and Bryna J. Hazelton and David Herne and David L. Kaplan and Justin C. Kasper and Barton B. Kincaid and Ronald Koenig and Eric Kratzenberg and Colin J. Lonsdale and Mervyn J. Lynch and S. Russell McWhirter and %Daniel A. Mitchell and %Miguel F. Morales and Edward H. Morgan and Divya Oberoi and Stephen M. Ord and Joseph Pathikulangara and Thiagaraj Prabu and Ronald A. Remillard and Alan E. E. Rogers and Anish A. Roshi and Joseph E. Salah and Robert J. Sault and N. Udaya Shankar and K. S. Srivani and Jamie B. Stevens and Steven J. Tingay and Randall B. Wayth and Mark Waterson and Rachel L. Webster and Alan R. Whitney and Andrew J. Williams and J. Stuart B. Wyithe},
journal= {arXiv preprint arXiv:1203.5790},
year = {2015}
}
Comments
20 pages, 6 tables, 12 figures. 1 online-only machine readable table. Submitted to ApJ