Observations of CO isotopic emission and the far-infrared continuum of Centaurus A

Maps are presented of the (C-12)O (1-0) line and the 100 and 50 micron far-IR continuum emission of Centaurus A, along with measurements of the(C-12)O (2-1), (C-13)O, and the C(O-18) lines at selected positions. The molecular gas is concentrated in the dust lane of Cen A, and the center of the rotation is the IR/radio nucleus. The distribution of the emission is in agreement with a tilted disk with an inclination of 78 +or - 3 deg and a total molecular gas mass of about 2-3 million solar.The velocity dispersion of the material is of the order of 60 km/s and is about constant along the disk. No evidence is found for strong velocity disturbances at the center. The absorption lines indicate that the properties of giant molecular clouds in the dust lane are comparable to those in the Galaxy. A simple one-component model of the molecular gas at the center indicates that the molecular emission arises from dense, optically thick gas