GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM)
  survey III: South Galactic Pole data release
  We present the South Galactic Pole (SGP) data release from the GaLactic and
Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. These data
combine both years of GLEAM observations at 72-231 MHz conducted with the
Murchison Widefield Array (MWA) and cover an area of 5,113 $\mathrm{deg}^2$
centred on the SGP at 20$^\mathrm{h}$40$^\mathrm{m}$ < RA <
05$^\mathrm{h}$04$^\mathrm{m}$ and $-48\deg$ < Dec < $-2\deg$. At 216 MHz, the
typical rms noise is $\approx 5$ mJy/beam and the angular resolution $\approx
2$ arcmin. The source catalogue contains a total of 108,851 components above
$5\sigma$, of which 77 per cent have measured spectral indices between 72 and
231 MHz. Improvements to the data reduction in this release include the use of
the GLEAM Extragalactic catalogue as a sky model to calibrate the data, a more
efficient and automated algorithm to deconvolve the snapshot images, and a more
accurate primary beam model to correct the flux scale. This data release
enables more sensitive large-scale studies of extragalactic source populations
as well as spectral variability studies on a one-year timescale.
