Warm dense gas in luminous protostellar regions - A submillimeter and far-infrared CO line study

Spectroscopic measurements of the CO J = 7-6 and J = 16-15 sub-mm/far-IR rotational lines are combined for a study of the molecular gas in four massive star formation regions: W51 IRS 2, W51 Main, G34.3+0.1, and W49. CO emission over a wide velocity range is found in three of the four regions. Mass outflows from newly formed stars in the two W51 sources carry an order-of-magnitude-greater mass and momentum than in the Orion/KL flow; it is concluded that mass outflow rates scale with source luminosity up to the most luminous galactic star formation regions.