ORNL heads DOE project that looks to the stars

September 18, 2001

OAK RIDGE, Tenn., - Through a newly funded Department of Energy project, astrophysicists at Oak Ridge National Laboratory and around the United States hope to gain a better understanding of what happens when stars die in spectacular explosions called core collapse supernovae.

To people like ORNL astrophysicist Tony Mezzacappa, this work is about more than just satisfying their curiosity. The project is aimed at answering some basic questions about the origin of life.

"Life as we know it would not exist if not for these incredible explosions of stars," said Mezzacappa, a member of ORNL's Physics Division. "When stars die in these explosions that generate billions upon billions of watts of energy, elements necessary for life are strewn throughout the galaxy and become part of the 'soup' from which our solar system formed."

The five-year $9.2 million Scientific Discovery through Advanced Computing (SciDAC) project headed by Mezzacappa will focus on several areas, but a major thrust will be on developing a standard model for core collapse supernovae. Modeling requirements for this work are severe.

"The advent of computing resources capable of trillions of calculations per second makes it possible to carry out the necessary large-scale three-dimensional simulations to understand the supernova explosion mechanism and all the phenomena that accompany the explosion of stars," Mezzacappa said.

While it takes millions of years for a star to evolve, the core collapse supernova explosion takes place in just hours. These events occur about two to three times each century in our galaxy.

Aside from the significant computational challenges of the project, Mezzacappa notes that this work, which draws from scientists at eight universities and the National Center for Supercomputer Applications, has strong ties to basic research missions of DOE.

"DOE has long been involved in both neutrino astrophysics and accelerator-based neutrino physics," Mezzacappa said. "This work will make important progress toward a standard model of supernovae similar to the development of the standard model for the sun. It also ties together much of DOE's efforts in the areas of high-energy and nuclear physics."

With accurate supernovae models, neutrinos from supernovae can tell scientists about the properties of the dense matter in a supernova.

"We want to learn about the explosion mechanism and then the composition of the star and what that can tell us about fundamental particle and nuclear physics," Mezzacappa said.

Another important aspect of the work includes learning more about how stable heavy elements are created. With this information, scientists hope to understand the chain of events leading to the formation of life on Earth.

Also of particular interest to DOE is a collaboration with NASA and new observations of the Earth's cosmic ray environment. Supernovae are likely the principal source and one of the acceleration mechanisms for cosmic rays.

"Our work addresses very broad themes important to DOE's national mission," Mezzacappa said. "The ability to model the movement of radiation through matter and its interaction with that matter is a concern not only for supernovae models but also for people who model internal combustion engines, climate patterns and to researchers seeking better tools for radiation therapy."

One of the collaborators is the University of Tennessee, where distinguished scientist Jack Dongarra and colleagues will be working on mathematical solutions (algorithms) to help solve the equations that govern the motion of neutrinos through the stellar material. Dongarra is also a member of a SciDAC team of computer scientists who specialize in measuring and optimizing the performance of computer programs.

Mezzacappa also said ORNL will be collaborating with members of the University of Tennessee's Joint Institute for Computational Sciences, whose expertise spans a number of areas of interest to ORNL.

SciDAC is an integrated program that will help create a new generation of scientific simulation computer programs. The programs will take full advantage of the extraordinary computing capabilities of computers capable of performing trillions of calculations per second to address increasingly complex problems.

The recently announced 51 DOE SciDAC projects will receive a total of $57 million this fiscal year to advance fundamental research in several areas related to the department's missions, including climate modeling, fusion energy sciences, chemical sciences, nuclear astrophysics, high-energy physics and high-performance computing.

In addition to the University of Tennessee and the National Center for Supercomputer Applications, collaborators for the project are North Carolina State University, Florida Atlantic University, the University of California-San Diego, the University of Washington, State University of New York at Stony Brook, Clemson and the University of Illinois at Urbana-Champaign. Individuals involved in the project from ORNL are David Dean and Mike Strrayer of the Physics Division and Ross Toedte of the Computer Science and Mathematics Division.
-end-
ORNL is a DOE multiprogram facility operated by UT-Battelle.

NOTES TO EDITORS:
If you would prefer to receive your press releases by e-mail, please send your e-mail address to news@ornl.gov. You may read other press releases from Oak Ridge National Laboratory or learn more about the lab if you have access to the Internet. You can find our information on the World Wide Web at http://www.ornl.gov/news

DOE/Oak Ridge National Laboratory

Related Supernovae Articles from Brightsurf:

FSU-led research team discovers unique supernova explosion
A 7-member international research team led by Florida State University Assistant Professor of Physics Eric Hsiao discovered a supernova that could help uncover the origins of the group of supernovae this star belongs to.

Discovery lays blame on supernova for extinction event nearly 360 million years ago
Between a decline in biodiversity and a series of extinction events, the Late Devonian period was not the most hospitable time on Earth.

New insights about the brightest explosions in the Universe
Swedish and Japanese researchers have, after ten years, found an explanation to the peculiar emission lines seen in one of the brightest supernovae ever observed -- SN 2006gy.

New study sheds light on conditions that trigger supernovae explosions
For the first time, researchers were able to demonstrate the process of detonation formation using both experiments and numerical simulations carried out on supercomputers.

Scientists observe year-long plateaus in decline of type Ia supernova light curves
A team of scientists, including a researcher from Queen's University Belfast, have discovered that the fading of infrared light following Type Ia supernovae explosions can be interrupted, with brightness staying the same for up to a year.

Hubble sets sights on an explosive galaxy
When massive stars die at the end of their short lives, they light up the cosmos with bright, explosive bursts of light and material known as supernovae.

Subaru Telescope captures 1800 exploding stars
The Subaru Telescope has captured images of more than 1800 exploding stars in the Universe, some located 8 billion light years from Earth.

Researchers wonder if ancient supernovae prompted human ancestors to walk upright
Supernovae bombarded Earth with cosmic energy starting as many as 8 million years ago, with a peak some 2.6 million years ago, initiating an avalanche of electrons in the lower atmosphere and setting off a chain of events that feasibly ended with bipedal hominins.

Stars exploding as supernovae lose their mass to companion stars during their lives
Stars over eight times more massive than the sun end their lives in supernovae explosions.

Zwicky Transient Facility spots a bumper crop of supernovae, black holes and more
The Zwicky Transient Facility (ZTF), an automated sky survey project based at Caltech's Palomar Observatory near San Diego, California, has produced its first bounty of new results.

Read More: Supernovae News and Supernovae Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.