Sketch of the relative sizes of mm-wave emission (orange), the X-ray corona (purple), and UV emission from the accretion disc (blue) in the centre of RXJ1131, derived from the microlensing analysis under the assumption that UV- and mm-wave emission are co-centric. The mm-wave emission is too compact to arise from a dusty torus; it is significantly smaller than the accretion disc and comparable to the X-ray corona size. 1 R_g = 5.7 × 10⁻⁶ pc.