April 9, 2009

Extragalactic study solves infrared puzzle

A U.S.-led study that shows all of Earth's far infrared background comes from distant galaxies has essentially solved the question of the radiation's origin.

The BLAST (Balloon-borne Large-Aperture Sub-millimeter Telescope) project led by Mark Devlin of the University of Pennsylvania collected data 120,000 feet above Antarctica, enabling researchers to peer into the distant universe at wavelengths nearly unattainable from the ground.

During the 1980s and 1990s, certain galaxies called Ultraluminous Infrared Galaxies were found to be forming hundreds of times more stars than local galaxies, the scientists said. Those starburst galaxies, 7 billion-10 billion light-years from Earth, were thought to make up the Far Infrared Background discovered by satellite.

The BLAST results confirmed all the Far Infrared Background comes from those individual distant galaxies. It also determined there's as much energy in the Far Infrared Background as there is in the total optical light emitted by stars and galaxies in the universe.

BLAST has given us a new view of the universe, said University of Toronto Professor Barth Netterfield, enabling the BLAST team to make discoveries in topics ranging from the formation of stars to the evolution of distant galaxies.

The research that also included scientists from Wales, Mexico, France and Puerto Rico is detailed in the journal Nature.