Molecular gas properties of 12-μm Seyfert galaxies -: I.: The southern sample

We have used the 15-m Swedish European Southern Observatory (ESO) Submillimetre Telescope (SEST) to observe the J=1-->0 and J=2-->1 transition lines of CO in 30 Southern hemisphere Seyfert galaxies from the extended 12-mum sample of Rush, Malkan & Spinoglio. We detected CO J=1-->0 in 16 out of the 30 Seyfert galaxies and CO J=2-->1 in 17 out of the 30 Seyfert galaxies. From the observed spectra, various CO gas properties have been derived including the luminosity of the CO gas and, using a standard conversion factor, the H-2 mass. The average H-2 gas mass for Seyfert 1 galaxies was 3x10(9) M-circle dot for CO J=1-->0 and 1x10(9) M-circle dot for CO J=2-->1, while in comparison the H-2 gas mass for Seyfert 2 type galaxies was 11x10(9) M-circle dot for CO J=1-->0 and 3x10(9) M-circle dot CO J=2-->1. From this small sample of Seyfert galaxies, we tentatively support the conclusion that type 2 Seyfert galaxies contain more molecular gas than their type 1 counterparts.