  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
("disk-jet"). While both models can produce collimated relativistic outflows,
neither has successfully explained the observed jet morphology. In this paper,
by employing general relativistic magnetohydrodynamic simulations, and
considering nonthermal electrons accelerated by magnetic reconnection driven by
kink instability of the jet, we have obtained images by radiative transfer
calculations and compared them to millimeter observations of the jet in M87. We
find that the BZ-jet originated from a magnetically arrested disk around a
high-spin black hole can well reproduce the jet morphology, including its width
and limb-brightening feature.
