Core size (top), brightness temperature (middle), and magnetic field estimate (bottom) obtained from the EHT+ data set as a function of the distance to the central engine. The 15–230 GHz data in each panel are approximated by power law fits (solid lines, obtained as detailed in Sect. 3.1) and the fit results are annotated. The faded data points at are the RadioAstron measurements, while the filled markers correspond to VLBA observations. For comparability, we color the 1.66 GHz (L band) RadioAstron points the same as the 2 GHz (S band) VLBA points. For a M_• = 10⁸ M_⊙ black hole 1 pc =2 × 10⁵r_g with gravitational radius r_g = GM_•/c².