ART-XC effective area for doubly reflected events (blue) and singly reflected events (red) at 8.1 keV as a function of offset angle (top). ART-XC FoV-averaged effective area for doubly (blue) and singly reflected events (red) in the 4–35 keV energy band as a function of energy (bottom). The graphs for the effective area are based on the effective area of the simulated mirror system and on the efficiency of the spare detector.