Evaluation of New Submillimeter VLBI Sites for the Event Horizon Telescope

Abstract The Event Horizon Telescope (EHT) is a very long-baseline interferometer built to image supermassive black holes on event-horizon scales. In this paper, we investigate candidate sites for an expanded EHT array with improved imaging capabilities. We use historical meteorology and radiative transfer analysis evaluate site performance. Most of the existing in have median zenith opacity less than 0.2 at 230 GHz during March/April observing season. Seven 345 0.5 months. Out more 40 new locations analyzed, approximately half comparable sites, least 17 would be comparably good observing. A group favorable transmittance geographic placement leads greatly enhanced science horizon