Channel maps of the ¹²CO J = 1−0 and J = 2−1 line emission towards X Her, at the LSR velocities (units of km s^-1) specified in the top-left corner of each panel. No primary beam attenuation correction is applied. (Top) CO J = 1−0: contours are plotted from and with a spacing of 2.5σ, where σ = 10 mJy beam^-1. Equivalent negative contours are plotted in dashed lines. The last panel presents the continuum emission from and with a spacing of 2.5σ, with σ = 0.35 mJy beam^-1. The synthesized beam is at PA = 68°, and is drawn in the bottom-right corner of the two last panels. (Bottom) CO J = 2−1: the first contour and spacing are of 4σ, except for the channels marked with c, in the left-bottom corner, where they are 6σ, with σ = 16 mJy beam^-1. Equivalent negative contours are plotted in dashed lines. In these maps, and mainly in the channels marked with c, the recovering of short-spacing was very complex, and so we remain refrain from interpreting the extended distribution in the three central channels (see Sect. 4.1.5). The last panel presents the continuum emission with a contour spacing of 6σ from the first at 3σ, with σ = 0.6 mJy beam^-1. The synthesized beam is at PA = 49°, and is drawn in the bottom-right corner of the two last panels. The primary beams are plotted at half power in dotted lines in the last panels of the channel maps. The central coordinates are RA 16:02:39.140, Dec 47:14:25.55 (J2000).