Extended Data Fig. 3: The HI emission in the velocity range of 6550–6750 km s−1 (unsmoothed).
From: A 0.6 Mpc H i structure associated with Stephan’s Quintet
Contour map of integrated HI emission (unsmoothed) in the velocity range of 6550–6750 km s−1 overlaid on the composite color image (u, g, r) of the deep CFHT MegaCam observation. The red circle at bottom-right illustrates the angular resolution (FWHM =2.9') of the FAST map (unsmoothed). The contours start from NHI = 7.4 × 1017 cm−2 (at 2-σ level) with an increment of a factor of 2. The red lines delineate the boundary of the FAST observations. The cyan contours in the center are adopted from the VLA observations for the 6600 component of SQ8, with angular resolution of 19.4"×18.6". They have the base level at NHI = 5.8 × 1019 cm−2 and the increment of a factor of 2. The same Box A and Box B that mark the location of the diffuse feature in Figure 3a are plotted here to facilitate the comparison between the two figures.
