The Discovery of a New Massive Molecular Gas Component Associated with
  the Submillimeter Galaxy SMM J02399-0136
  We present CO(1-0), CO(3-2), and CO(7-6) observations using the Green Bank
Telescope (GBT) and the Atacama Large Millimeter Array (ALMA) of the z=2.8
sub-millimeter galaxy SMM J02399-0136. This was the first
submillimeter-selected galaxy discovered and remains an archetype of the class,
comprising a merger of several massive and active components, including a
quasar-luminosity AGN and a highly obscured, gas-rich starburst spread over a
~25 kpc extent. The GBT CO(1-0) line profile is comprised of two distinct
velocity components separated by about 600 km/s and suggests the presence of a
new component of molecular gas that had not been previously identified. The
CO(3-2) observations with ALMA show that this new component, designated W1, is
associated with a large extended structure stretching 13 kpc westward from the
AGN. W1 is not detected in the ALMA CO(7-6) data implying that this gas has
much lower CO excitation than the central starburst regions which are bright in
CO(7-6). The molecular gas mass of W1 is about 30% of the total molecular gas
mass in the system, depending on the CO--to--H_2 conversion factor. W1 is
arguably a merger remnant; alternatively, it could be a massive molecular
outflow associated with the AGN, or perhaps inflowing metal-enriched molecular
gas fueling the ongoing activity.
