Example cluster (DETID: 104037601010003, IAU Name: 3XMM J001737.3-005240) at a redshift of 0.2141 (spectroscopic redshift). Upper panel: X-ray image (EPIC PN from the pipeline products, 6′ × 6′) in [0.2–12.0] keV of XMM-Newton observation (0403760101) targeted at a starburst galaxy. The green circle (radius = 1′) and yellow box (3′ × 3′) are centred on the X-ray emission peak. Lower panel: SDSS colour image corresponding to the yellow box centred on the X-ray position as indicated by the cross-hair. Sources with spectroscopic redshifts from SDSS-DR12 are marked by red squares.