a) NH₃(1, 1) integrated intensity map (^∫T_MBdv in units of K km s^-1) of the molecular core L1251A. Each color box has a size of 40′′ × 40′′, and its bottom left corner corresponds to the telescope pointing. The parameters of the NH₃ peaks α,β, and γ are given in Table 1. The core exhibits a filamentary structure that can be enveloped by an ellipse (dashed line) with principal axes of 1140′′ and 89′′. b) Schematic configuration of the filament and peak positions of the ammonia cores T1–T4. The gray contours restrict ammonia emission to the lowest level of the integrated NH₃(1, 1) emission as in Fig. 3 in Tóth & Walmsley (1996). The location of the IRS sources are from Lee et al. (2010). The red star is the IR source detected by IRAS. The filled blue and red circles outline areas of the narrowest ammonia lines with FWHP line widths of, respectively, Δv ~ 0.2 km s^-1, and ~0.1 km s^-1; their offsets are listed in Table 1. c) The sum over the integrated intensities for a given RA, ∑ _ΔδI_Δα(Δδ). The (0, 0) map position and the distance to the source are as in Fig. 1.