2.5 × 3 arcmin region around eFEDS J083120.5+030949 (ACT-CL J0831.3+0310). Left: LS grz-band color image. Magenta contours are drawn from the X-ray surface brightness map, shown in the right panel. The magenta box shows the eFEDS position, and the white box shows the SZ position from ACT. Right: X-ray map, showing X-ray and SZ position with density contours for passive galaxies at z = 0.569 (cyan) and z = 0.852 (red).