  The Event Horizon Telescope (EHT) provides a unique opportunity to probe the
physics of supermassive black holes through Very Large Baseline Interferometry
(VLBI), such as the existence of the event horizon, the accretion processes as
well as jet formation. We build a theoretical model which includes an Advection
Dominated Accretion Flow (ADAF) and a simple radio jet outflow. The predicted
spectral energy distribution (SED) of this model is compared to observations to
get the best estimates of the model parameters. Also the model-predicted radial
emission profiles at different frequency bands can be used to predict whether
the inflow can be resolved by the EHT.
