Channel maps of the ¹²CO J = 1−0 and J = 2−1 line emission toward R Cas 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 3σ and from there with a spacing of 3σ, where σ =  11mJy beam^-1. Equivalent negative contours are plotted in dashed lines. The last panel presents the continuum emission with a first contour and contour spacing of 4σ, where σ = 0.6 mJy beam^-1. The synthesized beam, plotted in the bottom-right corner of last panels, is in size, with PA = 52°. (Bottom) CO J = 2−1: contours are plotted at 3.5, 8, 13, 19, 25 and 31σ and from there with a spacing of 8σ, where σ = 25 mJy beam^-1. Equivalent negative contours are plotted in dashed lines. The last panel presents the continuum emission with a first contour and contour spacing of 4 and 6σ respectively, where σ = 1 mJy beam^-1. The synthesized beam, plotted in the bottom-right corner of last panels, is in size for the channel maps, for the continuum panel, with PA 11°. The primary beams are plotted at half power in dotted lines in the last panels of the channel maps. The central coordinates are RA 23:58:24.91, Dec 51:23:19.8 (J2000).