Astronomers connected the Atacama Pathfinder Experiment (APEX), in Chile, to the Submillimeter Array (SMA) in Hawaii, USA, and the Submillimeter Telescope (SMT) in Arizona, USA for the first time, to make the sharpest observation ever of the centre of a distant galaxy, the bright quasar 3C 279. The telescopes were linked using a technique known as Very Long Baseline Interferometry (VLBI). Larger telescopes can make sharper observations, and interferometry allows multiple telescopes to act like a single telescope as large as the separation — or “baseline” — between them. The baseline length from Chile (APEX) to Hawaii (SMA) is 9447 km, from Chile to Arizona (SMT) 7174 km, and from Arizona to Hawaii 4627 km.
Credit: ESO/L. Calçada