Publications of the Astronomical Society of Australia (PASA) doi: 10.1017/pasa.2019.xxx. The Mopra Southern Galactic Plane CO Survey — Data Release 3 Catherine Braiding1,8, G. F. Wong1,2, N. I. Maxted1,2, D. Romano1, M. G. Burton1,3, R. Blackwell4, M. D. Filipović2, M. S. R. Freeman1, B. Indermuehle5, J. Lau4, D. Rebolledo6,7, G. Rowell4, C. Snoswell4, N. F. H. Tothill2, F. Voisin4, and P. de Wilt4 1School of Physics, University of New South Wales, Sydney, NSW 2052, Australia 2School of Computing Engineering and Mathematics, Western Sydney University, Locked Bay 1797, Penrith, NSW 2751, Australia 3Armagh Observatory and Planetarium, College Hill, Armagh BT61 9DG, UK 4School of Physical Sciences, University of Adelaide, Adelaide, SA 5005, Australia 5CSIRO Astronomy & Space Science, Australia Telescope National Facility, PO Box 76, Epping, NSW 2121, Australia 6Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile 7National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA 8Email:
[email protected] Abstract We present observations of fifty square degrees of the Mopra carbon monoxide (CO) survey of the Southern Galactic Plane, covering Galactic longitudes l = 300–350◦ and latitudes |b| ≤ 0.5◦. These data have been taken at 0.6 arcminute spatial resolution and 0.1 km s−1spectral resolution, providing an unprecedented view of the molecular clouds and gas of the Southern Galactic Plane in the 109–115 GHz J = 1–0 transitions of 12CO, 13CO, C18O and C17O. We present a series of velocity-integrated maps, spectra and position-velocity plots that illustrate 6 Galactic arm structures and trace masses on the order of ∼10 M per square degree; and include a preliminary catalogue of C18O clumps located between l = 330–340◦.