Schematic diagrams of the four different channels of inverse Compton upscattering that produce X-ray emission from Sgr A*. Diagrams I–III (top left, top right, and bottom left) relate to flaring X-ray emission driven by the transient increase in the electron population in the NIR flare source whereas diagram IV (bottom right) relates to steady background X-ray emission from the accretion disk, as shown in cross section on one side of Sgr A*.