Complete ATCA Census of High-Mass Clumps (CACHMC) Legacy Survey

The conversion of turbulent structures within molecular clouds into high-mass stars and star clusters, the relation between Galactic and extragalactic star formation, and the effects of Galactic environment on star formation are fundamentally important, yet unsolved problems in astrophysics. The two major theories for high-mass star formation are "competitive accretion" and "turbulent core accretion" (for review see Motte et al. 2018). These theories make distinct predictions about the initial conditions within star-forming clumps, and how the gas on approximately 1-pc "clump" scales affects the accretion history on the 0.05-pc "core" scales at which individual stars form. This survey targeted over 50 cold, high-mass dust clumps, making observations of the sites of all current and future Galactic high-mass star formation. Ammonia and methanol emission lines were observed, along with recombination lines and a masing water line. The data will be used to characterise the turbulent structure within the clumps and to directly measure the locations, temperatures, masses, temporal sequence, and kinematics of their individual ~0.05 pc size star-forming cores.