  Molecular gas in the merging starburst galaxy NGC 3256 has been imaged with
the Submillimeter Array at a resolution of 1'' x 2'' (170 x 340 pc at 35 Mpc).
This is the first interferometric imaging of molecular gas in the most luminous
galaxy within z=0.01. There is a large disk of molecular gas (r > 3 kpc) in the
center of the merger with a strong gas concentration toward the double nucleus.
The gas disk having a mass of ~3*10^9 Msun in the central 3 kpc rotates around
a point between the two nuclei that are 850 pc apart on the sky. The molecular
gas is warm and turbulent and shows spatial variation of the intensity ratio
between CO isotopomers. High-velocity molecular gas is discovered at the
galactic center. Its velocity in our line of sight is up to 420 km/s offset
from the systemic velocity of the galaxy; the terminal velocity is twice as
large as that due to the rotation of the main gas disk. The high-velocity gas
is most likely due to a molecular outflow from the gas disk, entrained by the
starburst-driven superwind in the galaxy. The molecular outflow is estimated to
have a rate of ~10 Msun/yr and to play a significant role in the dispersal or
depletion of molecular gas from the galactic center. A compact gas
concentration and steep velocity gradient are also found around each of the
twin nuclei. They are suggestive of a small gas disk rotating around each
nucleus. If these are indeed mini-disks, their dynamical masses are ~10^9 Msun
within a radius of 170 pc.
