| Abstract: With some of the highest resolution images in astronomy, the Event Horizon Telescope has ushered in an age of horizon-scale imaging of supermassive black holes– our most direct probe of plasma astrophysics in strong gravity and the modern physics pillar of general relativity. With the first black hole images taken for the giant elliptical galaxy M87 and in our own Galactic Center at Sgr A*, theoretical models varying plasma magnetization and content, emission processes and black hole spin among others have revealed striking similarities and differences between astrophysical sources and general relativistic magnetohydrodynamics (GRMHD) simulations. In this investigation, models of magnetized plasma in the jet (or outflow)/accretion flow/black hole (JAB) system Sagittarius A* based on turbulent heating and deviations from the equipartition of particle and magnetic energies are input into a High Accuracy Relativistic Magnetohydrodynamics (HARM) simulation. Spectra, movies and light curves simulating hourly timescales show that these models aggregate into four quasi-stationary types: 1.) thin, asymmetric photon ring with best fit spectrum; 2.) coronal boundary layer with thin photon ring and steep spectrum; 3.) thick photon ring with flat spectrum; and 4.) extended outflow with low frequency spectral knee. For M87, a jet model based on a force-free flow in a HARM jet simulation is used to generate Stokes maps at Very Long Baseline Array (VLBA, 43 GHz) and Event Horizon Telescope (EHT, 230 GHz) scales. Positrons are also incorporated into the general relativistic ray tracer IPOLE combined with turbulent heating models for M87 to display positron effects on GRMHD simulations varying plasma content from ionic (e-p) to pair (e-e+), showing stark differences in polarization signatures between standard and normal evolution (SANE) and magnetically arrested disk (MAD) accretion modes due to Faraday effects. The cleanest observational signature in the MAD Stokes maps is the vanishing of circular polarization for increasing positron content (particularly for times when flux eruptions are prominent) and for SANE rapidly varying electric vector polarization angles with changing positron content. The inclusion of electrons, positrons and protons in our radiative transfer pipeline thus provides a powerful probe of the composition of JAB systems-- and helps set the stage for time-dependent analysis in black hole movies. Link to the Event Video |