The Greenland Telescope (GLT)* and Submillimeter VLBI
One of the ultimate observation goals in astrophysics is to directly observe the immediate surrounding of a black hole with angular resolution comparable to its event horizon. Observing and imaging its event horizon would be extremely important because it would open a new window on the study of General Relativity in the strong field regime, accretion and outflow processes at the edge of a black hole, the existence of an event horizon, and fundamental black hole physics, e.g. spin.
ASIAA has access to both the SMA and ALMA, linked together as a VLBI system, a potential angular resolution of a few micro-arcseconds can be achieved. There are two supermassive black holes (SMBH) with apparent sizes large enough to resolve with VLBI at submillimeter wavelengths: SgrA* at the Galactic Center, and the nucleus of M87. ASIAA proposes to add a third telescope to form a triangle with these telescopes. The presence of three telescopes will enable imaging, which would not be possible with a single baseline consisting of the SMA and ALMA.
The National Science Foundation (NSF) in the United States awarded the 12m ALMA-NA Vertex Prototype Telescope to a team led by the ASIAA in 2011. Our partners include the SAO, the NRAO, and the MIT Haystack Observatory, and we proposed to deploy the 12m Telescope to Greenland in order to pursue submm-VLBI. Given the presence of the South Pole Telescope (SPT) in South Pole, submm-VLBI can be done for the southern sky by combining the SPT with the SMA and ALMA. For the northern sky, Summit Station at 3200m in Greenland in the Arctic Circle, would be the best location for submm-VLBI with the SMA and ALMA. We are in the process of upgrading the performance of the 12m telescope, now renamed the Greenland Telescope (GLT).