Spatial and spectral distribution of the CO gas towards Kes 17 from ThrUMMS (Barnes et al. 2015). (a) Colour-coded image of the ¹²CO (in red) and the ¹³CO (in green) J =1–0 line emissions, integrated from −31 to −14 km s⁻¹. The yellow regions are areas where the two CO isotopologue emissions overlap. The contours (levels 0.034, 0.35, 0.75, and 1.2 mJy beam⁻¹, with a beam smoothed to the 80″ spatial resolution of the CO data) delineate the 843 MHz continuum radiation from Kes 17. For reference, the inset in the upper left corner displays the structure of the SNR shell as observed by the SUMSS (45″ resolution). The overlaid grid consists of the series of boxes (1′.5 in size) used to analyse the kinematics of the CO gas. The H II region G304.465–00.023 in the field is also labelled (Urquhart et al. 2022). (b) Collection of ¹²CO (in red) and ¹³CO (in green) J =1–0 spectra extracted from the boxes, numbered from 1 to 42, in panel a. The original datasets were convolved to a resolution of 80″ to reduce the graininess. The yellow contours superimposed on the spectra correspond to the radio continuum emission from Kes 17.