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

• Published in: Monthly notices of the Royal Astronomical Society 2004-10, Vol.353 (4), p.1151-1160
• Main Authors: Strong, Matt, Pedlar, Alan, Aalto, Susanne, Beswick, Rob J, Curran, Stephen, Booth, Roy
• Format: Article
• Language: English
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2004.08139.x

We have used the 15-m Swedish European Southern Observatory (ESO) Submillimetre Telescope (SEST) to observe the J= 1 1 0 and J= 2 1 1 transition lines of CO in 30 Southern hemisphere Seyfert galaxies from the extended 12-km sample of Rush, Malkan & Spinoglio. We detected CO J= 1 1 0 in 16 out of the 30 Seyfert galaxies and CO J= 2 1 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 H2 mass. The average H2 gas mass for Seyfert 1 galaxies was 3 x 109 M[odot] for CO J= 1 1 0 and 1 x 109 M[odot] for CO J= 2 1 1, while in comparison the H2 gas mass for Seyfert 2 type galaxies was 11 x 109 M[odot] for CO J= 1 1 0 and 3 x 109 M[odot]CO J= 2 1 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.