8-12 juin, 2014


Environmental Dependence of Molecular Gas and Star Formation in Spiral Galaxies from the JCMT Nearby Galaxies Legacy Survey

Angus Mok (McMaster University)

Christine Wilson (McMaster University), NGLS Collaboration

We present the results from a sample of 77 HI-selected spiral galaxies within 25 Mpc from the JCMT Nearby Galaxies Legacy Survey (NGLS), subdivided into isolated, group, and cluster samples, to study the effects of environment on their molecular gas and star formation. The CO J=3-2 line was observed with the James Clerk Maxwell Telescope (JCMT), a tracer for the dense gas linked to star formation, and combined with Hα star formation rates and stellar masses from the S4G Survey. This study also uses the method of survival analysis with the Kaplan-Meier estimator to account for the CO non-detected galaxies when comparing the molecular gas distributions of the three samples. We compare the star formation efficiency and gas depletion time to study the link between the gas and stars in these galaxies, as well as the specific star formation rate to compare their present and past star formation. While the molecular gas mass distributions are similar for all three samples, the star formation efficiencies showed much greater environmental variations.

Mode de présentation: 2014-06-09 13:45