Dr. Jingwen Wu, SMA-CfA

"Using Dense Gas Tracers to Study Massive Star Formation: From Near to
Far"

Abstract:
Massive star formation in the Milky Way occurs at dense, dusty
Giant Molecular Cloud cores, which can be well traced by dust continuum
emission and line emission from molecular dense gas tracers like HCN and
CS. We have conducted a series of mapping surveys with multiple HCN, CS
transitions, towards a large sample of Galactic massive star-forming
cores. Physical properties of these cores were derived; Line profiles were
simulated with an 1-D Monte Carlo code to constrain the dynamical models,
including infall, for these massive star-forming regions.

A linear correlation between infrared luminosity and the line luminosity
of dense gas was found for Galactic massive cores,
agree well to the correlation found in galaxies, but with a cut-off at
lower luminosity. This correlation implys that star formation may follows
a very simple law in terms of dense gas, from near to far. We propose a
model of massive star formation in the galaxies, to explain both the linear
behavior and the luminosity cut-off of the correlation