We investigate the connection between star formation and molecular gas properties in galaxy mergers at low redshift ( z \leq 0.06 ) .
The study we present is based on IRAM 30-m CO ( 1–0 ) observations of 11 galaxies with a close companion selected from the Sloan Digital Sky Survey ( SDSS ) .
The pairs have mass ratios \leq 4 , projected separations r _ { \mathrm { p } } \leq 30 kpc and velocity separations \Delta V \leq 300 km s ^ { -1 } , and have been selected to exhibit enhanced specific star formation rates ( sSFR ) .
We calculate molecular gas ( H _ { 2 } ) masses , assigning to each galaxy a physically motivated conversion factor \alpha _ { \mathrm { CO } } , and we derive molecular gas fractions and depletion times .
We compare these quantities with those of isolated galaxies from the extended CO Legacy Data base for the GALEX Arecibo SDSS Survey sample ( xCOLDGASS , Saintonge et al . 101 ) with gas quantities computed in an identical way .
Ours is the first study which directly compares the gas properties of galaxy pairs and those of a control sample of normal galaxies with rigorous control procedures and for which SFR and H _ { 2 } masses have been estimated using the same method .
We find that the galaxy pairs have shorter depletion times and an average molecular gas fraction enhancement of 0.4 dex compared to the mass matched control sample drawn from xCOLDGASS .
However , the gas masses ( and fractions ) in galaxy pairs and their depletion times are consistent with those of non-mergers whose SFRs are similarly elevated .
We conclude that both external interactions and internal processes may lead to molecular gas enhancement and decreased depletion times .