PN emission from the CSE of IK Tau. Upper two panels:IRAM 30 m data, lower two panels: SMA survey data. The vertical dashed lines indicate the rest frequency of the respective rotational transition. For J = 2 − 1 and 3–2 we also indicate the position of the HFS components with dash-dotted lines. For J = 6 − 5 we indicate the rest frequency of NaCl ν= 2,J = 22 − 21, and the range over which was integrated to obtain the moment-zero map in Fig. 3.