Column density maps of H₂CS, HDCS, and D₂CS towards L1544. The column density was computed assuming a constant T_ex = 12.3, 6.8, and 9.3 K for H₂CS, HDCS, and D₂CS, respectively. The solid white contours are 30%, 60%, and 90% of the peak intensity of the N(H₂) map of L1544 computed from Herschel/SPIRE data. The dotted white contours indicate the 3σ integrated emission contour with steps of 3σ (, rms_HDCS = 12 mK km s⁻¹, ).