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 $20^{\mathrm{h}} 40^{\mathrm{m}} < \mathrm{RA} < 05^{\mathrm{h}} 04^{\mathrm{m}}$ and $-48^{\circ} < \mathrm{Dec} < -2^{\circ} $ . At 216 MHz, the typical rms noise is ${\approx}5$ mJy beam–1 and the angular resolution ${\approx}2$ arcmin. The source catalogue contains a total of 108 851 components above $5\sigma$ , of which 77% 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.

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银河和河外全天空默奇森宽场阵列 (GLEAM) 调查 III：南银河极数据发布

我们展示了来自银河和河外全天空默奇森宽场阵列 (GLEAM) 调查的南银河极 (SGP) 数据。这些数据结合了使用默奇森宽场阵列 (MWA) 进行的 72–231 MHz 的 GLEAM 观测，覆盖面积为 5 113 $\mathrm{度}^{2}$ 以 SGP 为中心 $20^{\mathrm{h}} 40^{\mathrm{m}} < \mathrm{RA} < 05^{\mathrm{h}} 04^{\mathrm{m}}$ 和 $-48^{\circ} < \mathrm{Dec} < -2^{\circ} $ . 在 216 MHz 时，典型的 rms 噪声为 ${\约}5$ mJy光束–1和角分辨率 ${\约}2$ 弧分。源码目录共包含以上108851个组件 $5\sigma$ ，其中 77% 测量了 72 到 231 MHz 之间的频谱指数。此版本中对数据缩减的改进包括使用 GLEAM Extragalactic 目录作为天空模型来校准数据、更高效和自动化的算法对快照图像进行反卷积，以及更准确的主光束模型来校正通量比例。该数据发布使对河外源种群的更敏感的大规模研究以及一年时间尺度上的光谱变异性研究成为可能。