Sugar Molecule in Milky Way’s Habitable Zone Hints at Possibility of Life

Scientists recently detected an organic sugar molecule that is directly linked to the origin of life, in a region of our galaxy where habitable planets could exist.  Glycolaldehyde, (HOCH 2 -CH = O) the simplest of the monosaccharide sugars, can react with the substance propenal to form ribose, a central constituent of Ribonucleic acid (RNA), thought to be the central molecule in the origin of life.

The international team of researchers, including a researcher at University College London (UCL), used the IRAM radio telescope in France to detect the molecule in a massive star forming region of space, some 26000 light years from Earth.

“This is an important discovery as it is the first time glycolaldehyde, a basic sugar, has been detected towards a star-forming region where planets that could potentially harbour life may exist,” said Dr Serena Viti with University College London… Continue reading Sugar Molecule in Milky Way’s Habitable Zone Hints at Possibility of Life

Twisted Tale of our Galaxy’s Ring

The Milky Way's Twisted Ring

New observations from the Herschel Space Observatory show a bizarre, twisted ring of dense gas at the center of our Milky Way galaxy. Only a few portions of the ring, which stretches across more than 600 light-years, were known before. Herschel’s view reveals the entire ring for the first time, and a strange kink that has astronomers scratching their heads.

“We have looked at this region at the center of the Milky Way many times before in the infrared,” said Alberto Noriega-Crespo of NASA’s Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. “But when we looked at the high-resolution images using Herschel’s sub-millimeter wavelengths, the presence of a ring is quite clear.” Noriega-Crespo is co-author of a new paper on the ring published in a recent issue of Astrophysical Journal Letters…. Continue reading Twisted Tale of our Galaxy’s Ring

Massive Black Hole Smashed Into Milky Way 10 Million Years Ago

Evidence is emerging that a small galaxy, with a huge central black hole, must have recently collided with the Milky Way, say astronomers

The Milky Way gives the impression of a beautiful, calm field of stars. At the heart of all this is a supermassive black hole that sits, innocently, at the galactic centre.
In reality, however, our galaxy is a maelstrom of havoc on a scale that is hard to comprehend. And now evidence is emerging that the galactic centre has recently been much more active.
For a start, there is the dramatic recent discovery of two giant bubbles of gamma-ray emitting gas that extend some 20 kiloparsecs to the north and south of the galactic centre. Nobody is quite sure what generated the so-called Fermi Bubbles but they have more than a passing resemblance to the kind of jets emitted by active galactic nuclei.
Then there is the strange level of star formation going on near our supermassive black hole. The huge gravity associated with this black hole ought to tear gas clouds apart and that should make star formation tricky. And yet, the galactic centre is home to three massive clouds in which tens of thousands of stars are currently being born.
While we’re talking about stars, we ought to mention the distinct lack of older stars in the centre. That’s certainly fishy since there’s no shortage of them elsewhere in the galaxy.
Finally, there is the unusual fluorescence coming from iron nuclei in a gas cloud close to our supermassive black hole. This is almost certainly an echo of gamma ray bombardment that must have occurred just a couple of hundred years ago.
Clearly, the centre of our galaxy was once much more active, perhaps even in the time since the American War of Independence.
Today, Meagan Lang at Vanderbilt University in Nashville and a few pals say they think they can explain all this activity.
Their idea is that a small satellite galaxy recently smashed into the Milky Way, bringing with it stars, gas and a huge black hole some 10,000 times more massive than the Sun.
Here’s what they say happened. The new black hole spiralled into our own, but not before slinging away most of the older stars from the galactic centre. Much of the new dust was devoured by our own supermassive black hole, causing it to belch gamma ray-emitting jets into intergalactic space. The Fermi Bubbles are the remnants of these. The rest of the dust became a maelstrom of turbulence, perfect conditions for triggering the star formation we see today.
According to Lang and pals, the collision must have begun when the universe was still young. But they conclude that the collision effectively ended when the new black hole eventually combined with our own, an event that probably happened in the very recent past, perhaps just 10 million years ago.
That’s certainly an exciting idea, indeed one that has a touch of Hollywood about it.
But it’s also a theory that’ll need some careful thinking about, as Land and co readily admit: “While the case for a merger of the Milky Way with a satellite galaxy is not ironclad, it is a plausible explanation that naturally accounts for both the old and young stellar distributions and the recent violent past of Sgr A* [the supermassive black hole at the galactic centre].”
With any luck, it’ll generate some interesting debate, something that cosmologists are generally exceedingly good at.
Ref: arxiv.org/abs/1107.2923: Can A Satellite Galaxy Merger Explain The Active Past Of The Galactic Center?
http://www.technologyreview.com/blog/arxiv/27007/

Dark Mystery Cloud in the Milky Way

An Engine of Massive Star Creation?
A dark, mysterious cloud of dust (extending from the center, right) seems to flow out from a bright explosion in this false-color image in infrared light from the Spitzer Space Telescope. These views have revealed that the mystery cloud, called M17 SWex, is forming stars at a furious rate but has not yet spawned the most massive stars — O stars. To the left, on the trailing end of the dark cloud, such mammoth O stars create a dramatic contrast of brilliant light near the image’s center….
read more: http://www.dailygalaxy.com/my_weblog/2011/05/a-dark-mystery-cloud-discovered-in-milky-waya-dark-mysterious-cloud-of-dust-extending-from-the-center-right-seems-to-flow.html