Contours of the X-ray surface brightness superposed on optical images from the DSS database. The X-ray data are from the RASS or XMM-Newton observations. All images here and in the following figures are oriented such that north is up and east to the left. Upper left: RXCJ2332.5+2355, UGC 12655, X-ray data from RASS; upper right: RXCJ0015.5+1720, NGC 57, X-ray data from XMM-Newton; middle left: RXCJ0018.3+3003, NGC 71, X-ray data from RASS; middle right: RXCJ0021.0+2216, SRGb063, PPS 62, X-ray data from RASS; lower left: RXCJ0107.2+3224, NGC 383; X-ray data from XMM-Newton; lower right: RXCJ0110.9+3308, NGC 410, X-ray data from XMM-Newton.