Featured Research

from universities, journals, and other organizations

Christmas burst reveals neutron star collision

Date:
December 1, 2011
Source:
DOE/Los Alamos National Laboratory
Summary:
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.

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 a recent 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."


Story Source:

The above story is based on materials provided by DOE/Los Alamos National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. C. Thöne, A. de Ugarte Postigo, C. L. Fryer, K. L. Page, J. Gorosabel, M. A. Aloy, D. A. Perley, C. Kouveliotou, H. T. Janka, P. Mimica, J. L. Racusin, H. Krimm, J. Cummings, S. R. Oates, S. T. Holland, M. H. Siegel, M. De Pasquale, E. Sonbas, M. Im, W.-K. Park, D. A. Kann, S. Guziy, L. Hernández García, A. Llorente, K. Bundy, C. Choi, H. Jeong, H. Korhonen, P. Kubànek, J. Lim, A. Moskvitin, T. Muñoz-Darias, S. Pak, I. Parrish. The unusual γ-ray burst GRB 101225A from a helium star/neutron star merger at redshift 0.33. Nature, 2011; 480 (7375): 72 DOI: 10.1038/nature10611

Cite This Page:

DOE/Los Alamos National Laboratory. "Christmas burst reveals neutron star collision." ScienceDaily. ScienceDaily, 1 December 2011. <www.sciencedaily.com/releases/2011/12/111201141037.htm>.
DOE/Los Alamos National Laboratory. (2011, December 1). Christmas burst reveals neutron star collision. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2011/12/111201141037.htm
DOE/Los Alamos National Laboratory. "Christmas burst reveals neutron star collision." ScienceDaily. www.sciencedaily.com/releases/2011/12/111201141037.htm (accessed July 24, 2014).

Share This




More Space & Time News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) — The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) Video provided by AP
Powered by NewsLook.com
Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) — A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) — NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) — Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
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:

More Coverage


NASA's Swift Finds a Gamma-Ray Burst With a Dual Personality

Nov. 30, 2011 — A peculiar cosmic explosion first detected by NASA's Swift observatory on Christmas Day 2010 was caused either by a novel type of supernova located billions of light-years away or an unusual ... read more
from the past week

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