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Astronomers find rare spiral galaxy

08:25 AEST Thu Jul 19 2012

4 days 22 hours 18 minutes ago

Astronomers have stumbled upon an astonishing spiral galaxy that was born nearly 11 billion years ago, a finding that could spur a rethink of how galaxies formed after the Big Bang.

Dubbed BX442, the ancient star cluster was discovered in a survey of 300 distant galaxies carried out by the powerful Hubble Space Telescope and the Keck Observatory in Hawaii.

"Lo and behold, with no warning, BX442 and its spiral galaxy just popped out of the image. We couldn't believe it!" Alice Shapley of the University of California Los Angeles told AFP of the find reported in Nature journal.

"We were not expecting such a beautiful pattern, given that the vast majority of star-forming galaxies in the early universe look so irregular and lumpy."

BX442 is the first "grand design" spiral galaxy to be observed so early in history.

Located 10.7 billion light years away, it was created some three billion years after the universe was born in a superheated flash.

A "grand design" galaxy formation is one with well-defined arms spiralling out in opposite directions from a central cluster of stars in a pattern resembling an S, like our Milky Way.

Other galaxies observed this far back in time have irregular, clumpy structures, with conditions too hot to allow them to settle down into a spiral.

"The vast majority of old galaxies look like train wrecks," said Shapley.

"The discovery of BX442 tells us that a spiral pattern can form in the early universe, which we did not know," and represents a link between early, turbulent galaxies and the rotating spiral kind we find today.

Studying BX442 may help astronomers understand how spiral galaxies form

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I read about this a few days ago and it is simply amazing!

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Artist's Rendition:

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Published: Jul 18th, 2012

Astronomy | By Sergio Prostak

Astronomers Make Sharpest Direct Observations

Astronomers using three telescopes – APEX in Chile, SMA in Hawaii, and the Submillimeter Telescope in Arizona – have observed the heart of a distant quasar with unprecedented sharpness, two million times finer than human vision.

image_473.jpg

An artist’s impression of the quasar 3C 279 (ESO / M. Kornmesser)

The team was able to make the sharpest direct observation ever, of the center of a distant galaxy, the bright quasar 3C 279, which contains a supermassive black hole with a mass about one billion times that of the Sun, and is so far from Earth that its light has taken more than 5 billion years to reach us.

The telescopes were linked using a technique known as Very Long Baseline Interferometry (VLBI). Larger telescopes can make sharper observations, and interferometry allows multiple telescopes to act like a single telescope as large as the separation – or “baseline” – between them. Using VLBI, the sharpest observations can be achieved by making the separation between telescopes as large as possible.

For their quasar observations, the team used the three telescopes to create an interferometer with transcontinental baseline lengths of 9447 km from Chile to Hawaii, 7174 km from Chile to Arizona and 4627 km from Arizona to Hawaii. Connecting APEX in Chile to the network was crucial, as it contributed the longest baselines.

The observations were made in radio waves with a wavelength of 1.3 mm. This is the first time observations at a wavelength as short as this have been made using such long baselines. The observations achieved a sharpness, or angular resolution, of just 28 microarcseconds – about 8 billionths of a degree. This represents the ability to distinguish details an amazing two million times sharper than human vision. Observations this sharp can probe scales of less than a light-year across the quasar – a remarkable achievement for a target that is billions of light-years away.

The observations represent a new milestone towards imaging supermassive black holes and the regions around them. In future it is planned to connect even more telescopes in this way to create the so-called Event Horizon Telescope.

The Event Horizon Telescope will be able to image the shadow of the supermassive black hole in the center of our Milky Way galaxy, as well as others in nearby galaxies. The shadow – a dark region seen against a brighter background – is caused by the bending of light by the black hole, and would be the first direct observational evidence for the existence of a black hole’s event horizon, the boundary from within which not even light can escape.

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Spiral galaxies aren't rare! We live in one! Out in the spirally arm no less!

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I was taught that the universe as we know it was formed ~6 billion years ago. A galaxy dating 11 billion years ago throws that entire belief out the window.

How exactly can we date the lifespan of a galaxy?

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Astrophile: Blobby old galaxy boasts hidden arms

Astrophile is our weekly column on curious cosmic objects, from the solar system to the far reaches of the multiverse

Object: The giant elliptical galaxy Centaurus A

Distance: About 12 million light years

Centaurus A was facing a midlife crisis. The giant elliptical galaxy's brightest stars were old and puffy, and it had nearly run out of gas needed to create new ones. The galaxy was just a featureless blob that had lost its sparkle.

Then a chance encounter allowed boring old Centaurus A to have a fling with a younger, smaller galaxy. The event revived the elder partner, triggering a fresh round of star birth and creating one of its most notable features: a dark dust lane along its middle.

In a surprise twist, new observations show the cosmic hanky-panky also caused Centaurus A to sprout two spiral arms – something no other elliptical galaxy is known to have. The discovery offers new insights into how galaxies form and evolve, and hints at a new way for spiral structure to emerge.

Shocking revelation

The bisecting dust lane led astronomers in the early 19th century to think that Centaurus A might be two separate objects lying side by side. More recent studies have shown that the dust is most likely a disc left behind by a galactic merger.

By blocking visible light, the dust also conceals the intimacies of the galaxy's steamy affair. To gather more clues, Daniel Espada of the National Astronomical Observatory of Japan and colleagues looked at Centaurus A in radio wavelengths.

These longer waves emerge from carbon monoxide gas at the galaxy's centre and can pierce the dusty veil, allowing the team to trace otherwise hidden structures. What they saw was shocking.

"We were quite surprised to find what clearly looked like spiral arms," says team member Alison Peck of the Joint ALMA Observatory in Santiago, Chile. Their images show the tentacles of gas curving around the galaxy's middle, with widths and orientations similar to those of the arms of spiral galaxies like our Milky Way.

What's more, the gas tentacles are "moving in a way that you would expect spiral arms to move", says Peck.

Gassy tendrils

Bruce Elmegreen, a spiral-structure expert at the IBM Research Division in Yorktown Heights, New York, says the arms on Centaurus A are unique because they are made of molecular gas instead of stars, the main components of the Milky Way's armsartx_video.gif.

"It's really unusual," says Elmegreen. Usually a disc of gas around an object rotates in such a way that the gas clumps up rather than forming long filaments.

He suspects that Centaurus A is so massive and its stars are so centrally concentrated that the galaxy's rotating core creates a huge shear effect, one that sculpted the gas into spiral structures.

Since galaxies grow via mergers, the new study suggests it is possible that spiral arms exist on other elliptical galaxies. Unfortunately, most are too far away for us to get a detailed peek.

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I was taught that the universe as we know it was formed ~6 billion years ago. A galaxy dating 11 billion years ago throws that entire belief out the window.

How exactly can we date the lifespan of a galaxy?

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I want to be able to see that when I look up at the stars.

Beautiful.

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The oldest spiral galaxy found so far - cool.

I'm pretty sure we've known the approximate age of the universe for a long time...well...long as in say 50 years or so?

"The first direct observational evidence that the Universe has a finite age came from the observations of astronomer Edwin Hubble published in 1929.[16] Earlier in the 20th century, Hubble and others resolved individual stars within certain nebulae, thus determining that they were galaxies, similar to, but external to, our Milky Way Galaxy. In addition, these galaxies were very large and very far away. Spectra taken of these distant galaxies showed a red shift in their spectral lines presumably caused by theDoppler effect, thus indicating that these galaxies were moving away from the Earth. In addition, the farther away these galaxies seemed to be, the greater the redshift and thus the faster they seemed to be moving away. This was the first direct evidence that the Universe is not static but expanding. The first estimate of the age of the Universe came from the calculation of when all of the objects must have started speeding out from the same point. Hubble's initial value for age was very low, as the galaxies were assumed to be much closer than later observations found them to be."

Good info here:

http://www.universetoday.com/36278/age-of-the-universe/

I can't seem to find a date when we discovered that the universe is 13.75 billion years old...

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Spiral galaxies aren't rare! We live in one! Out in the spirally arm no less!

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I was taught that the universe as we know it was formed ~6 billion years ago. A galaxy dating 11 billion years ago throws that entire belief out the window.

How exactly can we date the lifespan of a galaxy?

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Waits patiently for an Apple fanboy to come in here pontificating about the superior OS in the iphone.

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Wow, I didn't realize that there was much of anything before 1983

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This space stuff is out of this world!

Save for the pun, I love these threads. They encourage me to delve into my inner astronomer.

Space is probably the coolest thing, ever.

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I was taught that the universe as we know it was formed ~6 billion years ago. A galaxy dating 11 billion years ago throws that entire belief out the window.

How exactly can we date the lifespan of a galaxy?

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Easy, give it a random number they think makes sense, who's going to question them anyways? Everything is a theory, scientists and such really don't know as much as people think they do...

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