Part of the sky image of the GC observation as obtained through IROS, between –44^◦ and +45^◦ in in the local frame along X and –35^◦ and +35^◦ in Y, zooming in on 70% of the total image (i.e., the fraction of sky pixels) showing the strongest sources in the FOV. The pixel unit is significance. Only sources brighter than 80 mCrab are labeled. The cross-like PSF of a source is not always apparent because its narrowness does not show well at this image reproduction; it is clearer when zooming in the pdf version of this paper.