VLA imaging of 12CO J = 1−0 and free-free emission in lensed submillimetre galaxies.

ABSTRACT We present a study using the Karl G. Jansky Very Large Array (VLA) of 12CO J = 1−0 emission in three strongly lensed submillimetre-selected galaxies (SMM J16359, SMM J14009 and SMM J02399) at z = 2.5-2.9. These galaxies span LIR = 1011-1013 L⊙, offering an opportunity to compare the interstellar medium of luminous infrared galaxies and ultraluminous infrared galaxies at high redshift. We estimate molecular gas masses in the range of 2-40 × 109 M⊙ using a method that assumes canonical underlying brightness temperature ( Tb) ratios for star-forming and non-star-forming gas phases and a maximal star formation efficiency. A more simplistic method - using XCO = 0.8 and the measured Tb ratios - yields gas masses twice as high. In SMM J14009 we find [ABSTRACT FROM AUTHOR]