  The linearly polarized millimeter and sub-millimeter emission in Sagittarius
A* is produced within 10 Schwarzschild radii of the supermassive black hole at
the Galactic Center and may originate from a hot magnetized accretion disk,
where electrons are heated efficiently by turbulent plasma waves. In such a
scenario, the flux density and polarization are very sensitive to the electron
heating rate and the inclination angle of disk, respectively, and the major
axis of the sub-millimeter intrinsic polarization, which is aligned with the
rotation axis of the disk, is perpendicular to the major axis of the polarized
near-infrared emission. In combination with MHD simulations, which study the
properties of the magnetic field and viscous stresses, the current spectral and
polarization measurements give tight constraints on the model parameters.
Simultaneous observations will be able to test the model.
