CN(1−0) spectra from the “Z” position used for Zeeman observations, highlighted in the CN(1−0) integrated intensity map here-above. a) Broad-band spectrum obtained at low spectral resolution (0.8 km s^-1 channel), covering the complete extent of all CN hyperfine components. b) VESPA spectrum obtained towards the CN(1 − 0) triplet (J = 1/2–1/2) at high spectral resolution (0.1 km s^-1 per channel originally, here smoothed to a 0.2 km s^-1 channel), towards the Z position. A fit of the hyperfine structure (red dashed spectrum) indicates that the systemic velocity is v_LSR = 8.7 ± 0.4 km s^-1. c) A VESPA spectrum obtained towards the CN(1–0) quadruplet (J = 3/2–1/2) at high spectral resolution (0.1 km s^-1 per channel originally, here smoothed to a 0.2 km s^-1 channel), towards the Z position.