The formation of jets in black hole accretion systems is a long-standing problem. It has been proposed that a jet can be formed by extracting the rotation energy of the black hole (“BZ-jet”) or the accretion flow (“BP-jet”). But both models are purely dynamical and it is unclear whether they can reproduce the various observations of jets. By performing general relativistic MHD simulations and considering electron acceleration by magnetic reconnection, we have calculated the predicted images by the two models and compared them to observations of the jet in M87, which is best observationally constrained among all jets. We find that the BZ-jet originating from a magnetically arrested disk around a high-spin black hole can well reproduce observations, including jet width and limb-brightening feature, while BP-jet cannot. The physical origin of reconnection is analyzed and found to be likely driven by magnetic eruption in the underlying accretion flow.
