GLEAM: The GaLactic and Extragalactic All-sky MWA survey
Abstract
GLEAM, the GaLactic and Extragalactic All-sky MWA survey, is a survey of the entire radio sky south of declination +25 deg at frequencies between 72 and 231 MHz, made with the Murchison Widefield Array (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 x 2.2/cos(DEC+26.7) arcmin with sensitivity to structures up to ~10 deg 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.
Keywords
Cite
@article{arxiv.1505.06041,
title = {GLEAM: The GaLactic and Extragalactic All-sky MWA survey},
author = {R. B. Wayth and E. Lenc and M. E. Bell and J. R. Callingham and K. S. Dwarakanath and T. M. O. Franzen and B. -Q. For and B. Gaensler and P. Hancock and L. Hindson and N. Hurley-Walker and C. A. Jackson and M. Johnston-Hollitt and A. D. Kapinska and B. McKinley and J. Morgan and A. R. Offringa and P. Procopio and L. Staveley-Smith and C. Wu and Q. Zheng and C. M. Trott and G. Bernardi and J. D. Bowman and F. Briggs and R. J. Cappallo and B. E. Corey and A. A. Deshpande and D. Emrich and R. Goeke and L. J. Greenhill and B. J. Hazelton and D. L. Kaplan and J. C. Kasper and E. Kratzenberg and C. J. Lonsdale and M. J. Lynch and S. R. McWhirter and D. A. Mitchell and M. F. Morales and E. Morgan and D. Oberoi and S. M. Ord and T. Prabu and A. E. E. Rogers and A. Roshi and N. Udaya Shankar and K. S. Srivani and R. Subrahmanyan and S. J. Tingay and M. Waterson and R. L. Webster and A. R. Whitney and A. Williams and C. L. Williams},
journal= {arXiv preprint arXiv:1505.06041},
year = {2017}
}
Comments
17 pages, 7 Figures, 4 tables. Accepted for publication in the Publications of the Astronomical Society of Australia (PASA)