The Arizona Radio Observatory CO Mapping Survey of Galactic Molecular
  Clouds: III. The Serpens Cloud in CO J=2-1 and 13CO J=2-1 Emission
  We mapped 12CO and 13CO J = 2-1 emission over 1.04 square deg of the Serpens
molecular cloud with 38 arcsec spatial and 0.3 km/s spectral resolution using
the Arizona Radio Observatory Heinrich Hertz Submillimeter telescope. Our maps
resolve kinematic properties for the entire Serpens cloud. We also compare our
velocity moment maps with known positions of Young Stellar Objects (YSOs) and
1.1 mm continuum emission. We find that 12CO is self-absorbed and 13CO is
optically thick in the Serpens core. Outside of the Serpens core, gas appears
in filamentary structures having LSR velocities which are blue-shifted by up to
2 km/s relative to the 8 km/s systemic velocity of the Serpens cloud. We show
that the known Class I, Flat, and Class II YSOs in the Serpens core most likely
formed at the same spatial location and have since drifted apart. The spatial
and velocity structure of the 12CO line ratios implies that a detailed
3-dimensional radiative transfer model of the cloud will be necessary for full
interpretation of our spectral data. The starless cores region of the cloud is
likely to be the next site of star formation in Serpens.
