Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Christmas burst reveals neutron star collision

02.12.2011
Old model, new data: A match made in the heavens

A strangely powerful, long-lasting gamma-ray burst on Christmas Day, 2010 has finally been analyzed to the satisfaction of a multinational research team. Called the Christmas Burst, GRB 101225A was freakishly lengthy and it produced radiation at unusually varying wavelengths. But by matching the data with a model developed in 1998, the team was able to characterize the star explosion as a neutron star spiraling into the heart of its companion star.

The paper, "The unusual gamma-ray burst GRB 101225A from a helium star/neutron star merger at redshift 0.33," appears in tomorrow's issue of the journal Nature. Christina Thöne of Spain’s Instituto de Astrofísica de Andalucía is the lead author, and Los Alamos computational scientist Chris Fryer is a contributor.

Fryer, of the Lab's Computer, Computational, and Statistical Sciences Division, realized that the peculiar evolution of the thermal emission (first showing X-rays with a characteristic radius of ~1011 cm followed by optical and infra-red emission at ~1014 cm) could be naturally explained by a model he and Stan Woosley of the University of California at Santa Cruz had developed in 1998.

"The Helium Merger Model explained all the properties we were seeing," Fryer said, although he noted that proving this required a series of additional computational models by the international theory team studying this "Christmas burst" and the work still under way. Fryer is working with Wesley Even of the Los Alamos X Theoretical Design Division, using the U.S. Department of Energy’s Advanced Simulation and Computing codes to study the emission of this burst in more detail.

"What we think happened is that a primary neutron star was orbiting in a close binary relationship with a companion star, and the companion expanded into a gas giant phase and enveloped the neutron star," Fryer said. "The neutron star spiraled into the core of the helium companion, with the friction of that passage ejecting the helium star’s envelope and creating a shell that produced the conditions needed to explain the different characteristic radii that we were seeing."

When the neutron star transformed into a black hole and the jet of gamma rays blasted outward, it struck the shell of the old star’s gas envelope at 1014 centimeters, which produced anomalous results and made this GRB look very different from previously seen events. Normally GRBs are incredibly brief, powerful, and pretty much invisible astronomical events that are almost gone before they’re detected.

Since the 2004 launch of the NASA satellite Swift, which carries a device called a Burst Alert Telescope, with triggering software developed at Los Alamos, GRBs have been identified and documented on a regular basis. And when Swift tagged this Christmas Burst, the international teams jumped to their telescopes and computers to capture it. Identifying it, however, has taken nearly a year.

Having the existing model on hand, one that seemed unlikely to ever be tested in the real world, was a happy coincidence, Fryer said. "We really thought it was unlikely that the field would produce data sufficient to prove this neutron/helium star collision scenario, and yet, here it has done it."

This burst may be one of a class of bursts (including XRF060218) that is explained by this model. "This is the game we're in right now with astronomical transients," Fryer said. "Weird objects can teach us a lot about the physics and we are no longer throwing them out as being too weird to explain. Now we can compare our unusual models to some of these unusual GRBs and they’re starting to match up."

About Los Alamos National Laboratory

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and URS for the Department of Energy's National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.

LANL news media contact: Nancy Ambrosiano, (505) 667-0471, nwa@lanl.gov

Nancy Ambrosiano | EurekAlert!
Further information:
http://www.lanl.gov

More articles from Physics and Astronomy:

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>