First Einstein@Home Search Results Published
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| Discovery of a pulsar orbiting a neutron star or black hole, with a sub-hour orbital period, would provide tremendous opportunities to test General Relativity. |
Results of the first Einstein@Home search for continuous wave sources in LIGO S5 data have been published in
Physical Review D. The project’s objective is to find the first physical evidence of one of Einstein’s greatest predictions — the existence of gravitational waves. It is one of the world's largest public volunteer distributed computing projects, with more than 200,000 people donating time on their computers to search data for signals from unknown pulsars.
Gravitational waves are ripples in the fabric of space and time produced by events in the universe such as exploding stars (supernovae) or extremely dense, rapidly rotating stars (pulsars). They carry new information about their sources and the nature of gravity itself and will help scientists “see” invisible events in space by mathematically mapping the ripples.
But to scan the massive amounts of data to make the comparisons requires enormous computing ability, found by borrowing idle cycles. distributed computing approach was constructed with input from the architects of the SETI@Home project which searches radio telescope data for signs of extraterrestrial life.
Based at the University of Wisconsin—Milwaukee (UWM) and the Albert Einstein Institute (AEI) in Germany, the revolutionary astrophysics project is analyzing data taken by the Pulsar Arecibo L-band Feed Array (PALFA) Consortium at the Arecibo Observatory in Puerto Rico, which is the largest single-aperture radio telescope on the planet and is used for studies of pulsars, galaxies, solar system objects and the Earth's atmosphere. Using new methods developed at the AEI, Einstein@Home searches Arecibo radio data to find binary systems consisting of the most extreme objects in the universe: a spinning neutron star orbiting another neutron star or a black hole.
Current searches of radio data lose sensitivity for orbital periods shorter than about 50 minutes. But the enormous computational capabilities of the Einstein@Home project (equivalent to tens of thousands of computers) make it possible to detect pulsars in binary systems with orbital periods as short as 11 minutes.
"Discovery of a pulsar orbiting a neutron star or black hole, with a sub-hour orbital period, would provide tremendous opportunities to test General Relativity and to estimate how often such binaries merge," said Professor Jim Cordes of Cornell University and Chair of the Arecibo PALFA Consortium.
“The mergers of such systems are among the rarest and most spectacular events in the universe. They emit bursts of gravitational waves that current detectors might be able to detect, and they are also thought to emit bursts of gamma rays just before the merged stars collapse to form a black hole,” he added.
The large data sets from the Arecibo survey are archived and processed initially at Cornell and other PALFA institutions. For the Einstein@Home project, data are sent to the Albert Einstein Institute in Hannover via high-bandwidth internet links, pre-processed and then distributed to computers around the world. The results are returned to AEI, Cornell and UWM for further investigation.
"The Einstein@Home computing resources are a perfect complement to the data management systems at the Cornell Center for Advanced Computing and the other PALFA institutions," Cordes said.
For more information: http://einstein.phys.uwm.edu/