High-resolution , CO ( 1 \to 0 ) interferometry of the ultraluminous infrared galaxy IRAS 14348-1447 is presented .
The merger system has a molecular gas mass of \sim 3 \times 10 ^ { 10 } M _ { \odot } and a projected nuclear separation of 4.8 kpc ( 3.5″ ) , making it one of the most molecular gas-rich galaxies known and an ideal candidate for studying the intermediate stages of an ultraluminous merger event .
The CO morphology shows two molecular gas components associated with the stellar nuclei of the progenitors , consistent with the idea that the molecular disks are gravitationally bound by the dense bulges of the progenitor galaxies as the interaction proceeds .
In contrast , less luminous infrared galaxies observed to date with projected nuclear separations of \lesssim 5 kpc show a dominant CO component between the stellar nuclei .
This discrepancy may be an indication that the progenitors of mergers with lower infrared luminosity do not possess massive bulges , and that the gas is stripped during the initial encounter of their progenitors .
A comparison of the CO and radio luminosities of the NE and SW component show them to have comparable radio and CO flux ratios of f ( NE ) / f ( SW ) \sim 0.6 , possibly indicating that the amount of star-forming molecular gas in the progenitors is correlated with the supernovae rate .
The estimate of molecular gas masses of the nuclei and the extent of the radio emission are used to infer that the nuclei of IR 14348-1447 have gas densities comparable to the cores of elliptical galaxies .