First results from Mopra HCO^+^ maps

We present the first Mopra (ATNF) maps of the CHaMP survey region (300{deg}>l>280{deg}) in the HCO^+^J=1->0 line, which is usually thought to trace gas at densities up to 10^11^m^-3^. In this paper, we introduce the survey and its strategy, describe the observational and data reduction procedures, and give a complete catalog of moment maps of the HCO^+^J=1->0 emission from the ensemble of 303 massive molecular clumps.

From these maps we also derive the physical parameters of the clumps, using standard molecular spectral-line analysis techniques.