April 17, 2007

Case's south pole scientists aim new $19 m telescope at stars

To understand the origin and composition of the universe

John Ruhl and his South Pole research team from Case Western Reserve University's physics department were among scientists from nine universities that pointed the new $19.2 million South Pole Telescope (SPT) towards Jupiter in February to begin testing its power to help astrophysicists understand the universe.

"The combination of the large aperture, off-axis telescope, the large-detector array and the prime observing site will enable the deepest searches yet for new clusters of galaxies," said Ruhl. "We will use this census of galaxies as a tracer of the expansion of the universe."

By studying the expansion of the universe, the researchers will answer questions about the nature of dark energy, which Ruhl said is "known to be out there but which we know little about."

Eventually Ruhl's research team, which includes graduate student Zackary Staniszewski who is still at the South Pole for the Antarctic winter, will use the new data to help to build upon research that the team has conducted in the past, including observations that gave some of the best "baby pictures" pictures of the universe at approximately 300,000 years after the cosmic "Big Bang."

Those images of the early universe were captured by the Arcminute Cosmology Bolometer Array Receiver at the South Pole (ACBAR, built by Ruhl and collaborators at Carnegie Mellon University, University of California at Berkeley and Caltech), and the balloon-borne Boomerang instrument built by a collaboration including Ruhl's group, Caltech, the University of Toronto and the University of Rome.

ACBAR made very sensitive images of the early universe over many months of observing from the South Pole. These images detailed the behavior of the plasma of which the early universe was made. Ruhl describes this plasma as being "very similar to the plasma that makes up our sun," where atoms cannot form. Instead, they are broken into separate electrons, protons and heavier nuclei.

"The SPT is five times larger in diameter than the ACBAR telescope, so the resolution in our maps of the sky is five times better," he said. "The number of detectors is more than a factor of 10 greater, so the sensitivity of the maps will be much greater."

The collaboration plans to use the current receiver on the SPT for several years, targeting investigations of dark energy as well as more detailed studies of the cosmic microwave background (CMB).

The new 280-ton telescope is 75 feet tall and 33 feet across. It was built with funding by the National Science Foundation, the Kavli Foundation of Oxnard, Calif., and the Gordon and Betty Moore Foundation of San Francisco.

In addition to the Case cosmologists, researchers from the University of Chicago, the University of California at Berkeley, Lawrence Berkeley National Laboratory, the University of Illinois at Urbana-Champaign, the Harvard-Smithsonian Astrophysical Observatory, McGill University and NASA's Jet Propulsion Laboratory will utilize the telescope.

For more information contact Susan Griffith, 216.368.1004.

Posted by: Heidi Cool, April 17, 2007 03:42 PM | News Topics: Collaborations/Partnerships, Physics, Research, Science, Technology

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