NASA Chandra X-Ray Image: Supernova Shockwave Cosmic Cocoon

Using observations from NASA's Chandra X-ray Observatory, researchers have obtained 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 Nov. 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.

This composite image of UGC 5189A shows X-ray data from Chandra in purple and optical data from Hubble Space Telescope in red, green and blue. SN 2010jl is the very bright X-ray source near the top of the galaxy.

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 the first Chandra observation of SN 2010jl, the X-rays from the explosion's blast wave were strongly absorbed by a cocoon of dense gas 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.

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 supernova. 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.

Image Credit: X-ray: NASA/CXC/Royal Military College of Canada/P.Chandra et al); Optical: NASA/STScI

Glowing bioluminescent plankton - Maldives

Glowing bioluminescent plankton in the tide line washes up onto a beach on Vaadhoo Island, Raa Atoll, Maldives, with stars above and a ship's lights on the horizon

Picture: Doug Perrine / Barcroft Media

ESA Herschel Image: Luminous Infrared Galaxies

Thousands of galaxies crowd into this Herschel image of the distant Universe. Each dot is an entire galaxy containing billions of stars.

For more than a decade, astronomers have puzzled over strangely bright galaxies in the distant Universe.

These ‘luminous infrared galaxies’ appear to be creating stars at such phenomenal rates that they defy conventional theories of galaxy formation.

Now ESA’s Herschel infrared space observatory, with its ability for very sensitive mapping over wide areas, has seen thousands of these galaxies and pinpointed their locations, showing for the first time that they are packing themselves closely together, forming large clusters of galaxies by the force of their mutual gravity.

The mottled effect in the image gives away this clustering. All the indications are that these galaxies are busy crashing into one another, and forming large quantities of stars as a result of these violent encounters.

This image is part of the Herschel Multi-tiered Extragalactic Survey (HerMES) Key Project, which studies the evolution of galaxies in the distant, ancient Universe. The project uses the SPIRE (Spectral and Photometric Imaging REceiver) instrument on Herschel and has been surveying large areas of the sky, currently totalling 15 square degrees, or around 60 times the apparent size of the Full Moon.

This particular image was taken in a region of space called the Lockman hole, which allows a clear line of sight out into the distant Universe. This ‘hole’ is located in the familiar northern constellation of Ursa Major, The Great Bear.

The galaxies seen in this image are all in the distant Universe and appear as they did 10–12 billion years ago. They are colour coded in blue, green, and red to represent the three wavebands used for Herschel’s observation. Those appearing in white have equal intensity in all three bands and are the ones forming the most stars. The galaxies shown in red are likely to be the most distant, appearing as they did around 12 billion years ago.

HerMES will continue to collect more images, over larger areas of the sky in order to build up a more complete picture of how galaxies have evolved and interacted over the past 12 billion years.

ESA & SPIRE Consortium & HerMES consortia - Follow the link to the ESA Herschel image site - OSHI