Early Science with the Large Millimeter Telescope: discovery of the
  12CO(1-0) emission line in the ring galaxy, VIIZw466
  We report an early science discovery of the CO(1-0) emission line in the
collisional ring galaxy, VII Zw466, using the Redshift Search Receiver
instrument on the Large Millimeter Telescope Alfonso Serrano.The apparent
molecular-to-atomic gas ratio either places the ISM of VII Zw466 in the
HI-dominated regime or implies a large quantity of CO-dark molecular gas, given
its high star formation rate. The molecular gas densities and star formation
rate densities of VII Zw466 are consistent with the standard Kennicutt-Schmidt
star formation law even though we find this galaxy to be H2-deficient. The
choice of CO-to-H2 conversion factors cannot explain the apparent H2 deficiency
in its entirety. Hence, we find that the collisional ring galaxy, VII Zw466, is
either largely deficient in both H2 and HI or contains a large mass of CO-dark
gas. A low molecular gas fraction could be due to the enhancement of feedback
processes from previous episodes of star formation as a result of the
star-forming ISM being confined to the ring. We conclude that collisional ring
galaxy formation is an extreme form of galaxy interaction that triggers a
strong galactic-wide burst of star formation that may provide immediate
negative feedback towards subsequent episodes of star formation---resulting in
a short-lived star formation history or, at least, the appearance of a
molecular gas deficit.
