  Thioxoethenylidene (CCS) is an abundant interstellar molecule, and a good
tracer of high density and evolutionary stage of dense molecular clouds. It is
also a suitable candidate for Zeeman splitting observations for its high
splitting factor and narrow thermal linewidths. We report here EVLA 22.3 GHz
observations of three dense molecular cores TMC-1, TMC-1C and L1521B in the
Taurus Molecular Cloud complex to image the CCS 2_1-1_0 transition. For all
three sources, the clumpy CCS emission is most likely tracing the starless
cores. However, these compact structures account for only ~ 1-13% of the
integrated emission detected in single-dish observations, indicating the
presence of significant large scale diffuse emission in favorable conditions
for producing CCS.
