Maps of key envelope tracers toward B1-c (Class 0, top) and TMC1 (Class I, bottom) obtained with ACA. Contours represent continuum emission at 1.3 mm observed with ACA. Different distances to B1-c and TMC1 result in different spatial resolutions of the maps. Left: C¹⁸O 2–1. Middle: N₂D⁺ 3–2. Right: DCO⁺ 3–2. All moment-0 maps are integrated from −2.5 to 2.5 km s⁻¹ with respect to v_sys.