Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Super-rare, super-luminous supernovae are likely explosion of universe's earliest stars

02.11.2012
The most-distant, super-luminous supernovae found to date have been observed by an international team, including Raymond Carlberg of the University of Toronto's Department of Astronomy & Astrophysics. The stellar explosions would have occurred at a time when the universe was much younger and probably soon after the Big Bang.

"The objects are both unusually bright and unusually slow to fade. These are properties that are consistent with what is known as pair-instability supernova, a rare mechanism for explosion which is expected to happen for high-mass stars with almost no metal content. That is, the very first stars to form," said Carlberg.


This is an artist's impression of a super-luminous supernova exploding in an interacting and very strongly star-forming galaxy at high redshift.

Credit: Marie Martig and Adrian Malec, Swinburne University

The two supernovae, identified as SN2213 and SN1000+2016, were discovered in image data obtained via the Canada-France-Hawaii Telescope Legacy Survey. In recent years, various surveys have enabled astronomers to open new windows on the universe, including the discovery over the past decade of super-luminous supernovae that are tens to hundreds of times more luminous than regular supernovae. "The Canada-France-Hawaii Telescope Legacy Survey stands out as the first really deep survey of the sky, covering large volumes of the universe," said Carlberg, a Canadian leader of the Survey.

All of the processing of the image data was done at U of T using a search technique that first vastly narrows the search to the high redshift star-forming galaxies and then looks for supernovae that are more luminous than normal supernovae and have unusually long fading times — precisely the characteristics of pair-instability supernovae.

The pair-instability explosion mechanism only occurs in stars that are about 150-300 times more massive than the sun, explains Carlberg. No stars that massive form in the current universe because as stars are assembled they start nuclear burning and push away additional gas. However, in the very early days of the universe, the metal abundance of the gas is essentially zero, making it almost transparent so that it can fall on the forming star.

Such massive stars do not last long. They are so hot in the centre that pressure is lost causing a collapse to start, which then heats up the core even more. Eventually enough oxygen and silicon are created that their fusion causes a nuclear explosion much more luminous than other supernova mechanisms.

The paper, entitled "Super-luminous Supernova Discoveries at z=2.05 and z=3.90," is published online in Nature at http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11521.html and will appear in the November 8 print edition. The team also includes scientists from Swinburne University of Technology, Oxford, Wiezmann Institute of Science, University of California, Irvine and San Diego State University.

IMAGE AT: uoft.me/supernova

MEDIA CONTACTS:

Raymond Carlberg
Department of Astronomy & Astrophysics
University of Toronto
Raymond.carlberg@utoronto.ca
416-978-2198
Kim Luke
Communications
Faculty of Arts & Science
University of Toronto
Kim.luke@utoronto.ca
416-978-4352

Kim Luke | EurekAlert!
Further information:
http://www.utoronto.ca

More articles from Physics and Astronomy:

nachricht Pulses of electrons manipulate nanomagnets and store information
21.07.2017 | American Institute of Physics

nachricht Vortex photons from electrons in circular motion
21.07.2017 | National Institutes of Natural Sciences

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>