Channel maps of 21 cm brightness temperature for the NGC 2592 area. Data are from the LAB survey (Kalberla et al. 2005). Units are K. The three channels maps are for v_LSR = −21.6 km s^-1 (top), 4.1 km s^-1 (middle) and 13.4 km s^-1 (bottom). They correspond to the dashed lines of Fig. 4. We note the different dynamic range of each map. The area shown is the same as for the Planck radiance (Fig. 1). The black square indicates the MegaCam field.