Title :Metal poor molecular gas in edge cloud 2
Author : Paul Ruffle
Abstract :
Edge Cloud 2 (EC2) is the most distant star forming molecular cloud in the Milky Way. It has an
associated HII region excited by a metal depleted early B star, that appears to have triggered star
formation in EC2. EC2 is unique in representing an environment similar to the primordial gas from
which the Milky Way formed. Our own observations in EC2 have found an under abundance of
N-bearing molecules, which may be related to the lack of stellar processing at such large
Galactocentric distances. We are extending our observations to better trace the dense gas
associated with star formation, and to constrain molecular and elemental abundances, density
temperature, and column densities. We are also developing a chemical kinetic model to
determine age, chemical évolution and constrain elemental abundances.