Molecular Gas in the Nuclear Region of NGC 6240
  NGC 6240 is a luminous infrared galaxy in the local universe in the midst of
a major merger. We analyze high-resolution interferometric observations of warm
molecular gas using CO J = 3 - 2 and 6 - 5 in the central few kpc of NGC 6240
taken by the Atacama Large Millimeter Array. Using these CO line observations,
we model the density distribution and kinematics of the molecular gas between
the nuclei of the galaxies. Our models suggest that a disk model represents the
data poorly. Instead, we argue that the observations are consistent with a
tidal bridge between the two nuclei. We also observe high velocity redshifted
gas that is not captured by the model. These findings shed light on small-scale
processes that can affect galaxy evolution and the corresponding star
formation.
