A CS J = 2 -> 1 Survey of the Galactic Center Region.

We present a CS map of the galactic center region consisting of 15,000 spectra covering -1degree l 3.6degrees, -0.4degrees b 0.4 degrees, each having an rms noise of 0.15K in 1 MHz filters. CS is a high-excitation molecule, meaning that it is excited into emission only when the ambient density >~ 2x10(4) cm(-3). CS emission in the inner 2degrees of the galaxy is nearly as pervasive as CO emission, in stark contrast to the outer galaxy where CS emission is confined to cloud cores. Galactic center clouds are on average much more dense than outer Galaxy clouds. This can be understood as a necessary consequence of the strong tidal stresses in the inner galaxy.