A supernova cocoon breakthrough

May 15, 2012
This composite image shows the galaxy UGC 5189A in X-ray data from Chandra (purple) and optical data from Hubble (red, green and blue.) The very bright source near the top of the galaxy is SN 2010jl, a recently discovered supernova. Data from Chandra have provided the first X-ray evidence of a supernova shock wave breaking through a cocoon of gas surrounding the star that exploded in SN 2010jl. This discovery may help astronomers understand why some supernovas are much more powerful than others. Credit: X-ray: NASA/CXC/Royal Military College of Canada/P.Chandra et al); Optical: NASA/STScI

(Phys.org) -- Observations with NASA's Chandra X-ray Observatory have provided the first X-ray evidence of a supernova shock wave breaking through a cocoon of gas surrounding the star that exploded. This discovery may help astronomers understand why some supernovas are much more powerful than others.

On November 3, 2010, a supernova was discovered in the galaxy UGC 5189A, located about 160 million light years away. Using data from the All Sky Automated Survey telescope in Hawaii taken earlier, astronomers determined this supernova exploded in early October 2010 (in Earth's time-frame).

This of UGC 5189A shows X-ray data from Chandra in purple and from in red, green and blue. SN 2010jl is the very bright X-ray source near the top of the galaxy (mouse-over for a labeled version).

A team of researchers used Chandra to observe this supernova in December 2010 and again in October 2011. The supernova was one of the most luminous that has ever been detected in X-rays.

In optical light, SN 2010jl was about ten times more luminous than a typical supernova resulting from the collapse of a massive star, adding to the class of very luminous supernovas that have been discovered recently with optical surveys. Different explanations have been proposed to explain these energetic supernovas including (1) the interaction of the supernova's with a dense shell of matter around the pre-supernova star, (2) radioactivity resulting from a pair-instability supernova (triggered by the conversion of into particle and anti-particle pairs), and (3) emission powered by a neutron star with an unusually powerful magnetic field.

In the first Chandra observation of SN 2010jl, the X-rays from the explosion's blast wave were strongly absorbed by a of around the supernova. This cocoon was formed by gas blown away from the massive star before it exploded.

In the second observation taken almost a year later, there is much less absorption of X-ray emission, indicating that the blast wave from the explosion has broken out of the surrounding cocoon. The Chandra data show that the gas emitting the X-rays has a very high temperature -- greater than 100 million degrees Kelvin – strong evidence that it has been heated by the supernova blast wave.

The energy distribution, or spectrum, of SN 2010jl in reveals features that the researchers think are explained by the following scenario: matter around the supernova has been heated and ionized (electrons stripped from atoms) by X-rays generated when the blast wave plows through this material. While this type of interaction has been proposed before, the new observations directly show, for the first time, that this is happening.

This discovery therefore supports the idea that some of the unusually luminous supernovas are caused by the blast wave from their explosion ramming into the material around it.

In a rare example of a cosmic coincidence, analysis of the X-rays from the supernova shows that there is a second unrelated source at almost the same location as the . These two sources strongly overlap one another as seen on the sky. This second source is likely to be an ultraluminous X-ray source, possibly containing an unusually heavy stellar-mass black hole, or an intermediate mass black hole.

These results were published in a paper appearing in the May 1st, 2012 issue of The Astrophysical Journal Letters. The authors were Poonam Chandra (Royal Military College of Canada, Kingston, Canada), Roger Chevalier and Christopher Irwin (University of Virginia, Charlottsville, VA), Nikolai Chugai (Institute of Astronomy of Russian Academy of Sciences, Moscow, Russia), Claes Fransson (Stockholm University, Sweden), and Alicia Soderberg (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA).

Explore further: The Great Debate over whether the universe is small or large

Related Stories

Space image: New supernova remnant lights up

Sep 13, 2011

(PhysOrg.com) -- Using the Hubble Space Telescope, astronomers are witnessing the unprecedented transition of a supernova to a supernova remnant, where light from an exploding star in a neighboring galaxy, ...

Remnant of an explosion with a powerful kick?

Feb 02, 2012

(PhysOrg.com) -- Vital clues about the devastating ends to the lives of massive stars can be found by studying the aftermath of their explosions. In its more than twelve years of science operations, NASA's ...

Stellar Shrapnel Seen in Aftermath of Explosion

May 24, 2010

(PhysOrg.com) -- This beautiful composite image shows N49, the aftermath of a supernova explosion in the Large Magellanic Cloud. A new long observation from NASA's Chandra X-ray Observatory, shown in blue, ...

Supernova 1987A: Fast Forward to the Past

Aug 18, 2005

Recent Chandra observations have revealed new details about the fiery ring surrounding the stellar explosion that produced Supernova 1987A. The data give insight into the behavior of the doomed star in the ...

A Super-Efficient Particle Accelerator

Jul 01, 2009

This image of data from NASA's Chandra X-ray Observatory and the European Southern Observatory's Very Large Telescope shows a part of the roughly circular supernova remnant known as RCW 86.

New supernova remnant lights up

Jun 08, 2011

(PhysOrg.com) -- In 1987, light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost ...

Recommended for you

Mystery of rare five-hour space explosion explained

Sep 17, 2014

Next week in St. Petersburg, Russia, scientists on an international team that includes Penn State University astronomers will present a paper that provides a simple explanation for mysterious ultra-long gamma-ray ...

Glowing galaxies in telescopic timelapse

Sep 17, 2014

We often speak of the discoveries and data flowing from astronomical observatories, which makes it easy to forget the cool factor. Think of it—huge telescopes are probing the universe under crystal-clear ...

Violent origins of disc galaxies probed by ALMA

Sep 17, 2014

For decades scientists have believed that galaxy mergers usually result in the formation of elliptical galaxies. Now, for the the first time, researchers using the Atacama Large Millimeter/sub-millimeter ...

User comments : 0