West Virginia University physics professors and an undergraduate student have discovered a new astronomical phenomenon.
Duncan Lorimer and Maura McLaughlin, assistant professors in the Department of Physics in the Eberly College of Arts and Sciences, and David Narkevic, a senior physics and political science student from Philippi, detected a powerful, short-lived burst of radio waves.
The findings of their study appear in todays edition of the online journal Science Express; they are also available athttp://www.nrao.edu/pr/2007/brightburst.
This burst appears to have originated from the distant universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole,said Lorimer, who also serves as assistant astronomer at the National Radio Astronomy Observatory in Pocahontas County.
The discovery came about as Narkevic was re-analyzing archived data to find new pulsars that had burst sporadicallyas opposed to the usual type of these neutron stars which pulsate periodically.
The team looked at observations from the Small Magellanic Cloud recorded by the 210-foot Parkes radio telescope in Australia and surprisingly found the burst outside of the cloud in the distant universe. The cloud is a dwarf galaxy located about 200,000 light years from the Milky Way.
The discovery involved a bit of luck, Narkevic explained, because the survey included observations of the sky surrounding the clouds.
The burst of radio waves, considered a significant finding by astronomical standards, lasted less than five milliseconds. The signal was spread out with higher frequencies arriving at the telescope before the lower frequencies. This effect, called dispersion, is caused by the signal passing through ionized gas in interstellar and intergalactic space.
The amount of dispersion in this newly discovered burst indicates that it likely originated about 3 billion light-years from Earth.
Were actively looking for more of these powerful, short bursts in other archival pulsar surveys and hope to resolve the mystery of their origin,McLaughlin said.If we can associate these events with galaxies of known distance, the radio dispersion we measure can be used as a powerful new way to determine the amount of material in intergalactic space.
Using its recent results, the team predicts that hundreds of similar events will occur each day outside the Milky Way.
The team has not found the origin of the phenomenon, but it has a couple of theories: One idea is that it may be part of the energy released when a pair of superdense neutron stars collide and merge.
Another theory suggests that the burst of energy is the last gasp from an evaporating black hole.
We are primarily a program for researching pulsars, but this discovery potentially opens up a whole new area of study here at WVU ,Lorimer noted.The discovery parallels the story of gamma-ray bursts, which became a new field of astronomy and occupied the research of many scientists for years trying to identify their characteristics. This mysterious occurrence could trigger a new area of cosmic study that were involved in from the beginning.
In addition to Lorimer, McLaughlin and Narkevic, the research team includes Matthew Bailes of Swinburne University in Australia and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pa.
The pulsar research program at WVU began in May 2006 when Lorimer and McLaughlin were jointly appointed by the University and the National Radio Astronomy Observatory, which manages the worlds largest fully steerable radio telescope, the 100-meter Robert C. Byrd Green Bank Telescope.
The National Radio Astronomy Observatory is a facility of the National Science Foundation and is operated under cooperative agreement by Associated Universities Inc.
The Parkes radio telescope is part of the Australia Telescope, which is funded by the Commonwealth of Australia for operation as a National Facility.