SITELLE composite image from deep SN1, SN2 and SN3 data cubes of SQ. The red lines represent the Hα contours corresponding to all 175 SQ Hα emission regions defined in Sect. 2.3. The Hα regions from YTT, NGC 7319, NGC 7320c, and NG are labelled according to the nomenclature from Table B.1. Green and yellow labels identify the SQ Hα regions showing a broad and narrow line profile, respectively. A zoomed-in view of the areas marked with the white rectangles are shown in Fig. 6.