Density and kinematics of the W49A cloud core

The dense core of the W49A molecular cloud (Miyawaki et al. 1986, Schloerb et al. 1987) has been mapped in 5 different transitions of CS and C^(34)S, in order to determine its density structure. The three lower frequency transitions (CS J=3-2, CS J=5-4 and C^(34)S J=5-4) were observed with the IRAM 30m telescope, and the two highest frequency transitions (CS J=7-6 and C^(34)S J=7-6) with the Caltech Submillimeter Observatory. The beamsizes were in the range 12″ to 20″. As a calibration check, the CS J=7-6 line was observed with both telescopes, and was found to give a consistent temperature scale. The spectra at the peak of the emission are shown in Fig. 1.