  We present the results of high resolution mapping of the CO(1-0) and CO(2-1)
emission of the ultraluminous infrared galaxy (ULIRG) IRAS 10190+1322, with the
IRAM interferometer, down to an angular resolution of ~0.3 arcsec. This object
is composed of two interacting galaxies with a projected nuclear separation of
6 kpc, and was selected to analyze the physical and dynamical properties of the
molecular gas in each galaxy in order to study the conditions that lead a
galaxy pair to become ultraluminous in the infrared. With the exception of Arp
220, the closest ULIRG, this is the first time that the CO emission is
morphologically and kinematically resolved in the two interacting galaxies of a
ULIRG system. In one of the galaxies the molecular gas is highly concentrated,
distributed in a circumnuclear disk of 1.7 kpc in size. The molecular gas in
the presumably less infrared luminous galaxy is distributed in a more extended
disk of 7.4 kpc. The molecular gas mass accounts for ~10% of the dynamical mass
in each galaxy. Both objects are rich enough in molecular gas, Mgas ~ 4 10^9
Msun, as to experience an infrared ultraluminous phase.
