A spectrum from a single ATCA baseline showing the detection of 12.2 maser and thermal emission, made possible by the BIGCAT upgrade.

The ATCA has been off-line since November 18 in order for the second part of the BIGCAT upgrade to be undertaken — doubling the bandwidth able to be recorded in all bands (except the 16cm band) from 2×2 GHz to 4×2 GHz. Together with this upgrade comes the capability of extending the 4cm beyond the fixed 4 to 12 GHz range of the CABB era. This is of particular interest as there is a spectral line of methanol at 12.179 GHz. Methanol (CH3OH) is an abundant molecule in a wide range of interstellar conditions. Methanol can be detected as broader, weaker thermal emission, and as bright, narrow spikes of maser emission, with both evident in the spectrum taken towards the massive star-forming region G331.278-0.188 above. While the ATCA has previously been used for highly cited papers from observations of the 6.7 GHz methanol line, and Murriyang, the Parkes 64 radiotelesope, has in the past undertaken surveys of both 6.7 and 12.2 GHz methanol lines, the ATCA can now perform high angular resolution imaging of 12.2 GHz methanol features. The spectrum above shows the spectrum for a single ATCA baseline, from CA03 to CA06, and a single polarisation.