Astronomers building an Earth-size virtual telescope capable of photographing the event horizon of the black hole at the center of our Milky Way have extended their instrument to the bottom of the Earth, thanks to recent efforts by a team led by Dan Marrone of the University of Arizona.
Marrone, an assistant professor in the UA's Department of Astronomy and Steward Observatory, and several colleagues flew to the National Science Foundation's (NSF) Amundsen-Scott South Pole Station in December to bring the South Pole Telescope, or SPT, into the largest virtual telescope ever built - the Event Horizon Telescope (EHT). By combining telescopes across the Earth, the EHT will take the first detailed pictures of black holes.
The EHT is an array of radio telescopes connected 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.
Weighing 280 tons and standing 75 feet tall, the SPT sits at an elevation of 9,300 feet on the polar plateau at Amundsen-Scott, which is located at the geographic south pole. The University of Chicago built SPT with funding and logistical support from the NSF's Division of Polar Programs. The division manages the U.S. Antarctic Program, which coordinates all U.S. research on the southernmost continent.
The 10-meter SPT operates at millimeter wavelengths to make high-resolution images of cosmic microwave background radiation, the light left over from the Big Bang. Because of its location at the Earth's axis and at high elevation where the polar air is largely free of water vapor, it can conduct long-term observations to explore some of the biggest questions in cosmology, such as the nature of dark energy and the process of inflation that is believed to have stretched the universe exponentially in a tiny fraction of the first second after the Big Bang.
"We are thrilled that the SPT is part of the EHT," said SPT lead John Carlstrom, according to the press release. "The science, which addresses fundamental questions of space and time, is as exciting to us as peering back to the beginning of the universe."
This work was funded through NSF grants AST-1207752 to Marrone; AST-1207704 to Doeleman at MIT's Haystack Observatory; and AST-1207730 to Carlstrom at the University of Chicago.
