GaLactic and extragalactic all-sky Murchison Widefield Array survey eXtended (GLEAM-X) III: Galactic plane

We present the third data release for the Galactic and Extragalactic All-Sky Murchison Widefield Array eXtended (GLEAM-X) survey, covering ≈ 3\,800 deg ² of the southern Galactic Plane (GP) with 233∘ < l < 44∘ and |b| < 11∘ across a frequency range of 72–231 MHz divided into 20 sub-bands. GLEAM-X observations were taken using the ‘extended’ Phase- ii configuration of the Murchison Widefield Array (MWA), which features baselines ranging from approximately 12 m to 5 km. This configuration limits sensitivity to the diffuse structure of the GP, with an angular resolution range of about 45'' to 2' . To achieve lower noise levels while being sensitive to a wide range of spatial scales ( 45'' - 15∘ ), we combined these observations with the previous Galactic and Extragalactic All-Sky Murchison Widefield Array (GLEAM) survey. For the area covered, we provide images spanning the whole frequency range. A wide-band image over 170–231 MHz, with RMS noise of ≈\; 3–6 mJy beam ⁻¹ and source position accuracy within 1 arcsec, is then used to perform source-finding, which yields 98 207 elements measured across 20 × 7.68 MHz frequency bands. The catalogue is 90 $%$ complete at 50 mJy within 233∘ < l < 324∘ and at 125 mJy in 290∘ < l < 44∘ , while it is $99.3%$ reliable overall. All the images and the catalogue are available online for download.