Testing the Accretion Flow with Plasma Wave Heating Mechanism for Sagittarius a* by the 1.3MM Vlbi Measurements

Abstract

The vicinity of the supermassive black hole associated with the compact radio source Sagittarius (Sgr) A* is believed to dominate the observed emission at wavelengths near and shorter than $\sim$ 1 millimeter. We show that a general relativistic accretion flow, heated via the plasma wave heating mechanism, is consistent with the polarization and recent mm-VLBI observations of Sgr A* for an inclination angle of $\sim 45^\circ$, position angle of $\sim 140^\circ$, and spin $\lesssim 0.9$. Structure in visibilities produced by the black hole shadow can potentially be observed by 1.3 mm-VLBI on the existing Hawaii-CARMA and Hawaii-SMT baselines. We also consider eight additional potential mm-VLBI stations, including sites in Chile and New Zealand, finding that with these the basic geometry of the emission region can be reliably estimated.

ApJ accepted; 21 pages, 8 figures