Gamma ray burst: Astronomers spot strongest-ever explosion

The strongest gamma ray blast ever known, exceeding the power of 9,000 exploding stars, has been discovered by astronomers in the deep-space constellation Carina

The radiation burst occurred 12.2 billion light years away in deep space, in the constellation Carina. Its light has taken most of the age of the universe to reach us.
Gamma ray bursts are the most luminous explosions in the universe. Scientists believe they occur when exotic massive stars run out of fuel and collapse to form a black hole.
Jets of material powered by processes that are not yet fully understood are thought to blast outwards at nearly the speed of light, generating intense gamma rays.
The new explosion, designated GRB 080916C, was spotted last year by the American space agency NASA's Fermi Gamma-ray Space Telescope, which is designed to detect gamma radiation.
Astronomers soon discovered that the gamma ray burst belonged in the record books.
The short-lived blast, described in the online version of the journal Science, was more powerful than nearly 9,000 ordinary supernovae, or exploding stars.
Scientists calculated that the material emitting the gamma rays must have been moving at 99.9999 per cent the speed of light.
The explosion was enigmatic as well as spectacular due to a curious time delay separating the highest-energy emissions from the lowest.
Scientists are still trying to understand the reason for the time delay, which may have a straightforward physical cause or be due to peculiar quantum effects.
Professor Peter Michelson, a member of the Fermi Gamma-ray Space Telescope team, said: "Burst emissions at these energies are still poorly understood.
"This one burst raises all sorts of questions. In a few years, we'll have a fairly good sample of bursts, and may have some answers."

Engineers revolutionise nano-device fabrication

Washington : Engineers have created a process that may revolutionise the manufacture of nano-devices from computer memory to biomedical sensors by exploiting a novel type of metal.
The material can be moulded like plastics to create features at the nano-scale and yet is more durable and stronger than silicon or steel. The search for a cost-effective and manageable process for higher-density computer chip production at the nano-scale has been a challenge.
One solution is making nano-scale devices by simple stamping or moulding, like the method used for fabricating CDs or DVDs.
This however requires stamps or master moulds with nano-scale features. While silicon-based moulds produce relatively fine detail, they are not very durable. Metals are stronger, but the grain size of their internal structure does not allow nano-scale details to be imprinted on their surfaces.
Unlike most metals, "amorphous metals" known as bulk metallic glasses (BMGs) do not form crystal structures when they are cooled rapidly after heating.
Although they seem solid, they are more like a very slow-flowing liquid that has no structure beyond the atomic level - making them ideal for moulding fine details, said senior author Jan Schroers of the Yale School of Engineering & Applied Science.
Researchers have been exploring the use of BMGs for about a decade, according to Schroers. "We have finally been able to harness their unusual properties to transform both the process of making moulds and producing imprints," he said. "This process has the potential to replace several lithographic steps in the production of computer chips."
Schroers says BMGs have the pliability of plastics at moderately elevated temperatures, but they are stronger and more resilient than steel or metals at normal working temperatures, said an Yale release.
"We now can make template moulds that are far more reliable and lasting than ones made of silicon and are not limited in their detail by the grain size that most metals impose," said Schroers.
This research was published in Nature on Thursday.

Soon, electronic device that can become invisible

Washington: Scientists in California, US, have developed tiny electronic circuits that could pave the way for transparent electronics and other futuristic applications, including flexible electronic newspapers and wearable clothing displays.
In the new study, Chongwu Zhou and colleagues point out that although scientists have previously developed nano-sized transparent circuits, previous versions are limited to a handful of materials that are transparent semiconductors.
The researchers describe the development of transparent thin-film transistors (TTFTs) composed of highly aligned, single-walled carbon nanotubes - each about 1/50,000th the width of a single human hair.
They are transparent, flexible, and perform well.
Laboratory experiments showed that TTFTs could be easily applied to glass and plastic surfaces, and showed promise in other ways for a range of possible practical applications.
This research is a significant advance toward the long-sought goal of "invisible electronics" and transparent displays, which can be highly desirable for heads-up displays, wind-shield displays, and electronic paper.

Hubble captures exceptionally deep view of unusual spiral galaxy

Washington: A spectacular new image captured by the Hubble Space Telescope has revealed an exceptionally deep view of an unusual spiral galaxy.
The image of the galaxy, which is in the Coma Galaxy Cluster, has been created from data taken by the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope.
It reveals fine details of the galaxy, NGC 4921, as well as an extraordinary rich background of more remote galaxies stretching back to the early Universe.
The Coma Galaxy Cluster, in the northern constellation of Coma Berenices, the hair of Queen Berenice, is one of the closest very rich collections of galaxies in the nearby Universe.
The cluster, also known as Abell 1656, is about 320 million light-years from Earth and contains more than 1000 members.
The galaxies in rich clusters undergo many interactions and mergers that tend to gradually turn gas-rich spirals into elliptical systems without much active star formation.
As a result, there are far more ellipticals and fewer spirals in the Coma Cluster than are found in quieter corners of the Universe.
NGC 4921 is one of the rare spirals in Coma, and a rather unusual one. It is an example of an "anaemic spiral", where the normal vigorous star formation that creates a spiral galaxy's familiar bright arms is much less intense.
As a result, there is just a delicate swirl of dust in a ring around the galaxy, accompanied by some bright young blue stars that are clearly separated out by Hubble's sharp vision.
Much of the pale spiral structure in the outer parts of the galaxy is unusually smooth and gives the whole galaxy the ghostly look of a vast translucent jellyfish.
The long exposure times and sharp vision of Hubble also allowed it to not just image NGC 4921 in exquisite detail, but also to see far beyond into the distant Universe.
This image was created from 50 separate exposures through a yellow filter and another 30 exposures through a near-infrared filter using the Wide Field Channel of the Advanced Camera for Surveys on Hubble.