Molecular Cloud Cores in the Orion A Cloud. II. FCRAO CS (2–1) Data

CS (2-1) data of the Orion A Cloud obtained with the FCRAO 14 m telescope are shown. The CS (2-1) image shows the clumpy and filamentary structure of the Orion A cloud, as did our previous CS (1-0) image, obtained with the NRO 45 m telescope. The peak intensity TMB (CS 2-1) decreases more steeply than TMB (CS 1-0) toward the south along the filament. It is found that the gas density of the CS cores tends to be lower in the south of the cloud, and this explains the above difference in the line-intensity decrease. From CS and C34S data, we estimated the optical depth of CS (2-1) to be moderately high (2-5) and that of CS (1-0) to be typically less than unity.