High-resolution surveys of the Sagittarius a molecular cloud complex in ammonia, carbon monoxide, and isocyanic acid.
Observations of the Sagittarius A molecular cloud complex in 10 molecular transitions are presented. It is found that the excitation temperatures of CO and HNCO were in the range 10-30 K, with CO temperatures slightly higher. The rotation temperature T(rot) of NH3 emission in the 2-1 transition was 35 K, while T(rot) for NH3 in the 6-3 transition was about 80 k. The masses of the individual clouds were estimated by two methods, and the results rae found to be in good agreement for most cases. The three largest clouds had masses of about 3-5 x 10 to the 5th solar mass, while the four smaller features had masses of about 10 to the 5th solar mass. The estimated mean number densities were about 10 to the 4th-10 to the 5th per cu cm. The results were derived from surveys in the NH3, HNCO, CO-13, and CO-18 at an angular resolution of 1.5 arcmin over the region 12 to -12 arcmin, 0 to -8 arcmin. A series of contour maps of the Sagittarius A molecular cloud complex is provided, on the basis of the observations.