L _[CII] /L_FIR vs. L_{CO(1 − 0)}/L_FIR for LESS J033229.4 (red point with error bars dominated by the uncertainty in L_FIR) compared with Galactic star-forming regions (crosses), starburst nuclei (filled squares), non-starburst nuclei (open squares), normal galaxies (triangles), local ULIRGs (circles), and high-redshift sources (asterisks and diamonds). Objects known to have low metallicity are overplotted by red crosses. Black lines represent the solar metallicity PDR model calculations for gas density (n) and FUV field strength (G₀) from Kaufman et al. (1999). A vector indicates how galaxy data points are shifted for the PDR analysis in Sect. 3. This figure is adapted from Stacey et al. (2010), with additional data on BRI 1335-0417 (z = 4.41) from Riechers et al. (2008) and Wagg et al. (2010), and on the low metallicity galaxy NGC 4142 (Cormier et al. 2010). LESS J033229 is located near the high L _[CII] /L_{CO(1 − 0)} region occupied only by low metallicity galaxies.