This project has been awarded 404 hours to extend the JCMT HARP 13CO/C18O J=3-2 Inner Milky-Way Plane Survey (CHIMPS) and the 12CO J=3-2 survey (COHRS) into the inner Galactic Plane, the Central Molecular Zone (CMZ) and a section of the Outer Plane. When combined with the complementary 12CO/13CO/C18O J=1-0 survey at the Nobeyama 45m (FUGIN) at matching 15” resolution and sensitivity, and other current CO surveys, the results will provide a complete set of transition data with which to calculate accurate column densities, gas temperatures and turbulent Mach numbers, which otherwise depend on approximations and assumptions. These will be used to: analyse molecular-cloud properties across a range of Galactic environments; map the star-formation efficiency (SFE) and dense-gas mass fraction (DGMF) in molecular gas as a function of position in the Galaxy and its relation to the nature of the turbulence within molecular clouds; determine Galactic structure as traced by molecular gas and star formation; constrain cloud-formation models; study the relationship of filaments to star formation; test current models of the gas kinematics and stability in the Galactic-centre region and the flow of gas from the disc. It will also provide an invaluable legacy data set for JCMT that will not be superseded for several decades.
Coordinators: Toby Moore (UK), Yang Su (China), Erik Rosolowsky (Canada), Tetsuhiro Minamidani (Japan), Oscar Morata (Taiwan) and Kee-Tae Kim (South Korea)
– JCMT program code: M17BL004