THE MOLECULAR GAS CONTENT OF SPIRAL GALAXIES IN COMPACT-GROUPS

We present (CO)-C-12(J=1-0) line observations of 15 late-type opticall y selected galaxies in compact groups. In order to study the effects o f environment on the molecular content of compact group galaxies we us e the CO(1-0) emission to estimate an indicative molecular hydrogen co ntent of the target galaxies adopting a standard conversion factor X=N (H-2)/I(CO). We compare the frequency distribution of the normalized h ybrid molecular gas surface density to the one obtained for an optical ly selected reference sample of isolated galaxies. Despite their high- density environment, compact group galaxies have, on average, similar CO emission compared to isolated galaxies of same sizes and luminositi es. However there are some compact group galaxies with perturbed morph ologies and high far-infrared fluxes which have an enhanced CO emissiv ity.