SuperMALT: Physical and Chemical Properties of Massive and Dense Clumps

The SuperMALT survey is observing 76 MALT90 clumps at different evolutionary stages (from pre-stellar or quiescent to HII) in high excitation molecular lines and key isotopomers using the Apex 12m telescope with an angular resolution of $\sim$20" and a velocity resolution of $\sim$0.1 km/s. The aim of this survey is to determine the physical, chemical, and kinematical properties of the gas within clumps as they evolve. Here we report some preliminary results based on observations of the $J$=3-2 \& 4-3 lines of HNC, HCN, HCO$^+$, N$_2$H$^+$ and of the $J$=3-2 line of the isotopologue H$^{13}$CO$^+$. We find that the morphologies and line profiles vary with the evolutionary stage of the clumps. The average line width increases from quiescent to HII clumps while line ratios show hint of chemical differences among the various evolutionary stages.