Visual extinction maps of the observed regions. The contours in the Barnard 1b map (left) correspond to [7,14,21,28, 35,42,49,56,63,70] mag levels. The contours in the IC 348 map (right) correspond to [6,9,12,15,18,21,24] mag levels. These maps were obtained from the τ₈₅₀ optical depth maps in Zari et al. (2016) applying the K-band to V-band extinction ratio of ~1/16 (Nishiyama et al. 2008). The crosses mark the pointings from where the data were taken. Selected spectra of CH₃OH lines at 90 GHz (Table 2) and the H₂S 1_1,0 → 1_0,1 line observed at different offsets are included in the maps.