Integrated intensity maps of the transitions used in this work. (a) Integrated intensity map of CO(1–0). The white contour is drawn at 180 K km s⁻¹, the gray contours are drawn at [360, 720, 1440, 2880] K km s⁻¹, and the blue contour is drawn at 4300 K km s⁻¹. The horizontal lines in different colors inside the color bar mark the values of corresponding contours, and remain the same in the following figures. The solid black line marks the major axis, and the dashed black line marks the slice across the SW streamer, on which the black arrows show the positive directions of the PVDs in the following figures. The white arrow points to the SW streamer and remains the same in subsequent panels. The black cross marks the phase center of the observation and remains the same in subsequent figures. The beam size of 1.6″ is shown as an empty black circle in the bottom-left corner of each panel and remains the same in subsequent figures. (b) Integrated intensity map of ¹³CO(1–0). The gray contours are drawn at [12, 40, 120, 230, 460] K km s⁻¹. (c) Integrated intensity map of HCN(1–0). The gray contours are drawn at [12, 40, 120, 300, 670] K km s⁻¹. (d) Integrated intensity map of H¹³CN(1–0). The gray contours are drawn at [2, 8, 20, 50, 100] K km s⁻¹. (e) Integrated intensity map of N₂H⁺(1–0). The gray contours are drawn at [5, 20, 50, 100, 200] K km s⁻¹. (f) Integrated intensity map of CH₃OH(2_k–1_k). The gray contours are drawn at [5, 20, 50, 100, 200] K km s⁻¹.