Testing General Relativity with the Black Hole Shadow Size and Asymmetry of Sagittarius A*: Limitations from Interstellar Scattering

Ziyan Zhu, Michael D. Johnson, Ramesh Narayan

The Event Horizon Telescope (EHT), a global 230 GHz VLBI array, achieves an angular resolution of $\approx 20\mu \mathrm{as}$, sufficient to resolve the supermassive black hole Sagit…