Featured Research

from universities, journals, and other organizations

Relativistic Effects Play Major Role In Neutron Star Mergers

Date:
July 12, 1999
Source:
University Of Illinois At Urbana-Champaign
Summary:
A powerful numerical simulation developed at the University of Illinois has revealed that gravitational waves -- ripples in the fabric of space -- play a major role in coalescing neutron stars. The results of the simulation may aid in the future detection of gravitational waves.

CHAMPAIGN, Ill. -- A powerful numerical simulation developed at the University of Illinois has revealed that gravitational waves -- ripples in the fabric of space -- play a major role in coalescing neutron stars. The results of the simulation may aid in the future detection of gravitational waves.

Related Articles


"General relativity predicts that a pair of neutron stars orbiting one another will radiate energy in the form of gravitational waves," said Alan Calder, a researcher at the National Center for Supercomputing Applications (NCSA) at the U. of I. "This loss of energy will cause the stars to move closer and closer together, until they eventually collide."

The gravitational waves produced in such events are expected to be observed by highly specialized detectors -- such as the Laser Interferometric Gravitational-Wave Observatory -- that are being built. Because gravitational waves are extremely weak, however, theoretical templates of the anticipated waveforms will be necessary to extract the signal from the noisy background.

"A neutron star is the small but dense stellar core that remains after a supernova explosion," Calder said. "By using computer simulations and scientific visualization to study the merger of two neutron stars, we can make predictions in anticipation of detectors coming on line to actually measure the waveforms."

To run the simulation, Calder and his colleagues -- Douglas Swesty, a visiting research professor at the U. of I. and a professor of physics and astronomy at the State University of New York at Stony Brook; Edward Wang, a graduate student in the department of physics and astronomy at SUNY-Stony Brook; and NCSA visualization expert David Bock -- used the SGI/Cray Origin2000 supercomputer at the National Computational Science Alliance.

The researchers initially ran the simulation with only Newtonian hydrodynamics; then they added a post-Newtonian "correction" in the form of a relativistic radiation reaction.

"The radiation reaction dramatically altered the dynamics of the merger," said Calder, who demonstrated the simulation at the American Astronomical Society meeting in Chicago on June 3. "The reaction caused the stars to coalesce much faster, and led to very different gravitational waveforms. We also found that the final coalesced objects differed both in structure and in total angular momentum."

One particularly striking feature seen in the simulation is the formation of tidal arms during the merger that transport a substantial amount of material into a rapidly rotating disk surrounding the merger. Most of the energy that is being radiated in the form of gravitational waves comes from these tidally distorted regions, not from the most massive or most dense parts of the stars.

Although post-Newtonian methods "are extremely useful for predicting gravitational waveforms during the early stages of the inspiral," Calder said, "predicting the later stages -- where tidal effects and neutron star structure become significant -- will require a fully relativistic simulation."


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Relativistic Effects Play Major Role In Neutron Star Mergers." ScienceDaily. ScienceDaily, 12 July 1999. <www.sciencedaily.com/releases/1999/07/990712080808.htm>.
University Of Illinois At Urbana-Champaign. (1999, July 12). Relativistic Effects Play Major Role In Neutron Star Mergers. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/1999/07/990712080808.htm
University Of Illinois At Urbana-Champaign. "Relativistic Effects Play Major Role In Neutron Star Mergers." ScienceDaily. www.sciencedaily.com/releases/1999/07/990712080808.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins