MOS 1 image of ρ Oph, the positions of the two components from SIMBAD database are indicated with colored boxes. The centroid of X-ray events is much closer to the A component. The scale is linear, the events have been rebinned in blocks of 0.4′′ and smoothed with a Gaussian of σ = 1 pixel. The separation between the two components is ~ 2.8″. The core of the point spread function of MOS1 is about 2′′ and the astrometric precision is ~ 1.2″.