(a) C¹⁸O rotational temperature map. (b) C¹⁸O column density map. (c) C¹⁸O fractional abundance map overlaid with H₂ column density contours. The contours start at 6 × 10²¹ cm⁻², and increase by 3 × 10²¹ cm⁻². The beam size is shown in the lower right corner of each panel. In all panels, the (0, 0) offset corresponds to α_J2000 = 18^h28^m50.^s4, δ_J2000 = 00°49′58.′′72, the three green pluses indicate the positions of the three embedded YSOs, and the white crosses mark the positions of the seven dust cores (Enoch et al. 2007).