Title:	GLEAM: The galactic and extragalactic all-sky MWA survey
Authors:	Wayth, R.B. Lenc, E. Deshpande, A.A. Prabu, T. Udaya Shankar, N. Srivani, K.S. Subrahmanyan, Ravi Dwarakanath, K.S. +30 Co-authors
Issue Date:	22-Jun-2015
Publisher:	Cambridge University Press for Astronomical Society of Australia
Citation:	Publications of the Astronomical Society of Australia,2015,Vol.32, e025
Abstract:	GLEAM, the GaLactic and Extragalactic All-sky MWA survey, is a survey of the entire radio sky south of declination + 25° at frequencies between 72 and 231 MHz, made with the MWA using a drift scan method that makes efficient use of the MWA's very large field-of-view. We present the observation details, imaging strategies, and theoretical sensitivity for GLEAM. The survey ran for two years, the first year using 40-kHz frequency resolution and 0.5-s time resolution; the second year using 10-kHz frequency resolution and 2 s time resolution. The resulting image resolution and sensitivity depends on observing frequency, sky pointing, and image weighting scheme. At 154 MHz, the image resolution is approximately 2.5 × 2.2/cos (δ + 26.7°) arcmin with sensitivity to structures up to ~ 10° in angular size. We provide tables to calculate the expected thermal noise for GLEAM mosaics depending on pointing and frequency and discuss limitations to achieving theoretical noise in Stokes I images. We discuss challenges, and their solutions, that arise for GLEAM including ionospheric effects on source positions and linearly polarised emission, and the instrumental polarisation effects inherent to the MWA's primary beam.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/6290
ISSN:	1323-3580 1448-6083(online)
Alternative Location:	http://adsabs.harvard.edu/abs/2015PASA...32...25W http://arxiv.org/abs/1505.06041 http://dx.doi.org/10.1017/pasa.2015.26
Copyright:	2015 Astronomical Society of Australia
Appears in Collections:	Research Papers (A&A)

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