WVU researcher detects high-energy X-rays from mysterious collapsed star

A research team led by West Virginia University astrophysicist Maura McLaughlin has discovered high-energy X-ray pulsations coming from a mysterious type of collapsed star.

The team recently used data from the space telescope, XMM-Newton, to detect a strange kind of neutron star known as a rotating radio transient (RRAT). Its findings were published in The Astrophysical Journal in December.

This is the first time X-ray pulsations have been detected from a RRAT, said McLaughlin, an assistant professor in the Department of Physics in WVU’s Eberly College of Arts and Sciences. Previously astronomers had only seen radio outbursts from these objects.

A neutron star is the collapsed remnant of a massive star. Most are seen as radio pulsars, rotating quickly and sweeping lighthouse beams of radiation across space.

The RRATs, however, appear to rotate much more slowly. McLaughlin’s team first detected RRATs through bursts of radio waves. Only one burst is seen at a time, and the average time intervals between bursts range from four minutes to three hours.

It’s a puzzle how RRATs fit in with other types of collapsed stars.

“There are some interesting theories; one suggests RRATs are actually pulsars with asteroid belts around them,” said McLaughlin, who was the lead author of a 2006 Nature paper announcing the discovery of RRATs.

The recent observations were made using XMM-Newton’s European Photon Imaging Camera, which targeted the celestial object, RRAT J1819–1458. Astronomers observed this object for around 12 hours and detected pulsations in the X-ray data that show it to be rotating once every 4.26 seconds.

XMM-Newton is a joint NASA-European Space Agency orbiting observatory, designed to observe high-energy X-rays emitted from exotic astronomical objects such as pulsars, black holes and active galaxies.

Since the original discovery of 11 RRATs, McLaughlin’s team has found an additional 10. WVU students Dominic Ludovici of Morgantown and George Habib of Egypt have assisted McLaughlin in her search.

The discovery of this new source population means that the number of neutron stars in the Milky Way is likely much greater than previously thought, according to the WVU astrophysicist.

“We can now estimate there could be more than 300,000 neutron stars in the galaxy,” she said.

McLaughlin’s pulsar work with observatories around the world, including the National Radio Astronomy Observatory at Greenbank, has significantly expanded WVU’s program in astrophysics. The WVU researcher was part of an international team that discovered the first known double pulsar some 2,000 light-years away from Earth.

More information on the RRAT observations is available at the European Space Agency Web site: http://www.esa.int/esaSC/SEMJJF2MDAF_index_0.html.

WVU Physics Team Discovers New Phenomenon in Universe

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 the September 27, 2007, edition of the online journal Science Express; the findings are also available at http://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 sporadically–as 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 three billion light-years from Earth.

“We’re 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 we’re 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 world’s 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.

WVU awarded nearly $2 million in 2007 WVEPSCoR Research Challenge Grants

This news release was issued June 6, 2007, by WVU News and Information Services.


West Virginia University has been awarded nearly $2 million in grants this year for research initiatives from the West Virginia Experimental Program to Stimulate Competitive Research (WVEPSCoR).

University faculty members Julio F. Davalos, Arun Ross and Ever Barbero, all from the College of Engineering and Mineral Resources, and Maura McLaughlin from the Eberly College of Arts and Sciences, were recent recipients of 2007 Research Challenge Grants (RCG).

The awards will provide seed money for new research endeavors at WVU. Grants can be renewed for up to five years, providing researchers demonstrate they are making progress each year. Each grant is worth $1-2 million over the five-year period.

“The four RCG awards provide significant opportunities for clusters of faculty at WVU to develop programs of excellence in science and technology that will be better positioned to compete for federal agency funding,” said Curt Peterson, WVU associate vice president for research and economic development. “The awards will help to further develop their intellectual property and innovative research into emerging new business opportunities important to economic development in West Virginia.

“In addition, it is anticipated that some of these grants will provide a springboard for the research clusters to compete for national research centers supported by a federal agency over a sustained period of time,” he noted. “Thus, these awards are contributing to the growth of the research enterprise at WVU that is expected to increase prosperity in the state.”


For the rest of the news release, including photographs of the principal investigators and information about their specific projects, click here.

University High Student Named Winner In Siemens Competition

Dominic Ludovici, a student at University High School in Morgantown, has been awarded a $30,000 prize in the Siemens Competition in Math, Science and Technology, one of the nation’s premier high school science competitions.

Astrophysics research Ludovici conducted for his project, “A Search for Radio Pulsars Using the GMRT,” has the potential to advance the fields of general relativity, solid-state physics, planetary physics and cosmology. By running two different algorithms on data collected from scanning the plane of the galaxy at a radio frequency of 610 MHz, he discovered three pulsars which offer a testing ground for many physical theories. Ludovici is mentored by Dr. Maura McLaughlin, assistant professor in radio astronomy at West Virginia University.

For more information, visit the competition website at www.siemens-foundation.org/competition.