Kinetic gas temperature map derived from the I(HCN)/I(HNC) J=1–0 ratio (the color scale is the same as Fig. B.7) overlaid with the integrated intensity map of diazenylium N₂H⁺ J=1–0 (gray contours in steps of 3, 5, 10, 15, 20, 25, and 30 K km s⁻¹; see also Fig. B.4) for each observed region. All maps are shown with the same color-scale range for comparison. The σ value above each panel indicates the cutoff value for both maps. Stars mark the positions of protostellar sources, and squares mark the locations of starless cores. The filled circle marks the position of L1448 IRS2E, whose nature is debated. Straight lines indicate the outflow directions for the protostellar systems included in the MASSES survey (Stephens et al. 2017).