X-shaped structure,is a key signature of formation of the Milky Way galaxy

How Twitter helped solve Milky Way mystery

By IANS

Published: 21st July 2016 08:32 AM

Last Updated: 21st July 2016 08:32 AM

TORONTO: Taking help from Twitter, two astronomers have uncovered the strongest evidence yet that an enormous X-shaped structure made of stars lies within the central bulge of the Milky Way galaxy.

Previous computer models and observations of our own galaxy have suggested that the X-shaped structure existed.

But no one had observed it directly. Some astronomers argued that previous research that pointed indirectly to the existence of the X could be explained in other ways.

"There was controversy about whether the X-shaped structure existed. But our paper gives a good view of the core of our own galaxy. I think it has provided pretty good evidence for the existence of the X-shaped structure," said Dustin Lang, Research Associate at the Dunlap Institute for Astronomy & Astrophysics, University of Toronto.

The Milky Way Galaxy is a barred spiral galaxy -- a disk-shaped collection of dust, gas and billions of stars, 100,000 light-years in diameter.

The central bulge, like other barred galaxy's bulges, resembles a rectangular box or peanut when viewed -- as we view it -- from within the plane of the galaxy.

The X-shaped structure is an integral component of the bulge.

Lang's analysis was originally intended to aid in his research in mapping the web of galaxies beyond the Milky Way galaxy.

To help explore the maps he had developed from NASA's Wide-field Infrared Survey Explorer (WISE) telescope data, he created an interactive map-browsing website and tweeted an image of the entire sky.

"Melissa Ness, post-doctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, saw the tweet and immediately recognised the importance of the X-shaped structure," Lang noted.

"The bulge is a key signature of formation of the Milky Way galaxy. If we understand the bulge we will understand the key processes that have formed and shaped our galaxy," Ness added in a paper appeared The results appear in the Astronomical Journal.

It is also evidence that our galaxy did not experience major merging events since the bulge formed. If it had, interactions with other galaxies would have disrupted its shape.

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New electronic nose can smell pesticides[needed in India where all food are sprayed with pesticides]

New electronic nose can smell pesticides, nerve gas in miniscule concentrations

(KU Leuven)

Mon, 4 Jul 2016-08:25pm , London , PTI

The technology can also be farly easily integrated into smartphones, to turn them into gas detectors as well.

Researchers have built a sensitive electronic nose that can detect pesticides and nerve gas in very low concentrations, an advance which may help screen someone's breath for lung cancer and multiple sclerosis (MS).
The best-known electronic nose is the breathalyser. As drivers breathe into the device, a chemical sensor measures the amount of alcohol in their breath, researchers said. This chemical reaction is then converted into an electronic signal, allowing the police officer to read off the result.
Alcohol is easy to detect, because the chemical reaction is specific and the concentration of the measured gas is fairly high. But many other gases are complex mixtures of molecules in very low concentrations. Building electronic noses to detect them is thus quite a challenge. Now, researchers from KU Leuven in Belgium have built a very sensitive electronic nose with metal-organic frameworks (MOFs).
"MOFs are like microscopic sponges. They can absorb quite a lot of gas into their minuscule pores," said Ivo Stassen from KU Leuven. Researchers created a MOF that absorbs the phosphonates found in pesticides and nerve gases. "This means you can use it to find traces of chemical weapons such as sarin or to identify the residue of pesticides on food. This MOF is the most sensitive gas sensor to date for these dangerous substances," said Stassen. "The concentrations we are dealing with are extremely low: parts per billion - a drop of water in an Olympic swimming pool - and parts per trillion," he added.
"The chemical sensor can easily be integrated into existing electronic devices", said Rob Ameloot from KU Leuven. "You can apply the MOF as a thin film over the surface of, for instance, an electric circuit. Therefore, it is fairly easy to equip a smartphone with a gas sensor for pesticides and nerve gas," said Ameloot. "MOFs can measure very low concentrations, so we could use them to screen someone's breath for diseases such as lung cancer and MS in an early stage. Or we could use the signature scent of a product to find out whether food has gone bad or to distinguish imitation wine from the original," he said.
The findings were published in the journal Chemical Science.