[C II] 158 µm line intensity emitted from the surface of a PDR as a function of the cloud density \(n\) and the FUV flux incident on the cloud \(G_0\) . Contours are labeled with the line intensity in units of erg cm-2 s-1 sr-1. Models of Kaufman et al. 1999 are used with the standard model parameter set. The FITS file is available for download.