In this paper, we have made high spatial-resolution observations of CS in the protoplanetary nebula CRL 2688. CS emission (the 2-1 transition) is found to be doubly peaked at the core region and the direction of the peaks are misaligned to the bipolar axis. From these findings, we suspect that the CS abundance is enhanced in the postshocked region. CS molecules can be used as a probe for the shock chemistry in the protoplanetary nebulae.
© European Southern Observatory (ESO) 1997
Online publication: June 30, 1998