Structure and LSB feature in the group north of the core of the Hydra I cluster. Top left panel: Colour-composite image of the group, where the brightest members are marked. The image size is 15 × 15 arcmin². N is up, and E is left. The dashed orange box indicates the region where diffuse light is detected after all bright sources (stars and galaxies) were modelled and subtracted from the image. The residual is shown in the top right panel. On the NE side, the red circle marks the S-shape LSB feature detected on this side of the group, which is also shown in the lower left panel. The dashed blue box marks the region where the peculiar galaxy HCC 005 and the disrupted dwarf galaxy HCC 087 are located, which is shown in the lower right panel.