Left panel: RGB colour composite image obtained by combining g′-, r′-, and i′-band images of 13′ × 10′ field of view from Pan-Starrs1 public archive. Circles and squares correspond to galaxy members and non-members, respectively, obtained from our spectroscopic observations and SDSS-DR16 spectroscopic database. Superimposed, we also show the contour levels of isodensity galaxy distribution of likely members (see Sect. 3.3). Right panel: same RGB image but overplotting the contour levels of the XMM-Newton image corresponding to the observation ID 0841900101. The X-ray contours were obtained after smoothing the original image using a Gaussian filter with σ = 6 arcsec. Point sources and emission from NVSS 123050+344257 radio galaxy (ID 78) have been removed, masking them with circular apertures of 10–20 pixels radius. In both panels, the BCG and BGs are also marked. North is up and east is left.