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those baby blues: The universe in its youth was going through a blue period (see Hubble photo of Abell 2744, above), its stars blue like the young, hot stars seen in constellation Orion.

NASA photo via AP,

On April 1-2, the Hubble Space Telescope photographed a group of galaxies called Arp 274. Arp 274, also known as NGC 5679, is a system of three galaxies that appear to be partially overlapping in the image, although they may be at somewhat different distances. The spiral shapes of two of these galaxies appear mostly intact. The third galaxy, to the far left, is more compact, but shows evidence of star formation. Two of the three galaxies are forming new stars at a high rate. This is evident in the bright blue knots of star formation that are strung along the arms of the galaxy on the right and along the small galaxy on the left. The entire system resides at about 400 million light-years away from Earth in the constellation Virgo. (AP Photo/ Hubble Space Telescope/NASA) ORG XMIT: MIN2013040421305943

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Telescopes reveal big stars, faint galaxies of early universe

  • Article by: Joel Achenbach
  • Washington Post
  • January 25, 2014 - 6:16 PM

A quartet of galaxies spied with NASA’s Hubble Space Telescope are among the oldest yet discovered — more than 13 billion years old, born just 500 million years after the big bang.

Here’s what it looked like during the cosmic dawn: It was a wild and woolly party, with brilliant blue stars that aren’t ready to settle down into anything so structured as a conventional spiral galaxy. Instead, the early years of the universe featured a profusion of small, irregular galaxies that were popping with big, hot, super-luminous stars forming at a furious rate. Galaxies were colliding all over the place. Ray Villard, a spokesman for the Space Telescope Science Institute, said it’s like seeing the finale of a fireworks show, just that it’s close to the beginning of time.

The new peek into the early universe shed light on the growth and development of some of the earliest galaxies. And the findings provide hope that NASA’s infrared-optimized James Webb Space Telescope, set to launch in 2018, will be able to see even more from this obscure era in the universe’s history.

This is not the first time that Hubble, in its third decade of operation, has collected ancient light. But a new campaign, dubbed the Frontier Fields, adds data from the Spitzer, a telescope that observes in infrared, and the Chandra X-ray Observatory.

decade of operation, has collected ancient light. But a new campaign, dubbed the Frontier Fields, adds data from the Spitzer, which observes in infrared, and the Chandra X-ray Observatory. It exploits a phenomenon known as gravitational lensing. This is a maneuver that draws inspiration from Albert Einstein’s general theory of relativity, which describes how gravity curves the fabric of space and time. In the foreground of one new image (above) is a galaxy cluster named Abell 2744, containing hundreds of galaxies. “Foreground” is perhaps an imperfect term given that these galaxies are 3.5 billion light-years away. The gravity of the clustered galaxies creates a lensing effect that magnifies thousands of galaxies in the background — some of them more than 12 billion light-years away, having emitted that light in the very earliest era of galaxy formation. The initial expansion of the universe, known as the Big Bang, happened about 13.7 billion years ago. Garth Illingworth, professor of astronomy at the University of California, Santa Cruz, said that if you could have parked in that young universe, you would have seen those blue galaxies all around, many as big as our moon. But there were no planets then. Star formation picked up speed for several billion years. Then, about 9 billion years ago, the situation calmed down and became more organized. The expanding universe became home to billions of majestic spiral and elliptical galaxies — and, on one rock at least, to astronomers staring into the night sky.

Two venerable space telescopes, the Hubble and the Spitzer, have teamed to study the very early universe, and here’s what they see at the cosmic dawn: a wild and woolly party, with brilliant blue stars that aren’t ready to settle down into anything so structured as a conventional spiral galaxy.

Instead, the early years of the universe featured a profusion of small, irregular, blobby galaxies that were popping with big, hot, super-luminous stars forming at a furious rate. Galaxies were colliding all over the place.

Ray Villard, a spokesman for the Space Telescope Science Institute, which conducts Hubble research for NASA, said it’s like seeing the finale of a fireworks show, just that it’s close to the beginning of time.

The new results and images of the early cosmos were released Tuesday at the annual meeting of the American Astronomical Society at National Harbor.

This is not the first time that the Hubble, in its third decade of operation, has taken a “deep field” look at the universe, training its gaze on a tiny spot and holding it there to collect the ancient light. But a new observation campaign, dubbed the Frontier Fields, supplements Hubble time with data from the Spitzer, which observes in infrared, and another space telescope, the Chandra X-ray Observatory.

The new campaign exploits a phenomenon known as gravitational lensing. This is an opportunistic maneuver that draws inspiration from Albert Einstein’s general theory of relativity, which describes how gravity curves the fabric of space and time.

In the foreground of one new image is a galaxy cluster named Abell 2744, containing hundreds of galaxies. “Foreground” is perhaps an imperfect term given that these galaxies are 3.5 billion light-years away — it has taken 3.5 billion years for the light to reach the Hubble. The gravity of the clustered galaxies creates a lensing effect that magnifies thousands of galaxies that are far in the background — some of them more than 12 billion light-years away, having emitted that light in the very earliest era of galaxy formation.

“Light following a path around those clusters is bent,” Jennifer Lotz, an astronomer at the Space Telescope Science Institute, said at a news conference Tuesday.

The initial expansion of the universe, known as the Big Bang, happened about 13.7 billion years ago, a measurement that has become more precise in the past few years with new data from space telescopes. Theorists believe it took about 400 million years for the first stars to ignite and the first galaxies to form. The Hubble can’t see quite that deeply in time and space, but the earliest galaxy-forming epoch is a target for NASA’s James Webb Space Telescope, scheduled for launch in 2018.

The universe in its youth was going through a blue period, because the stars were blue, just like the young, hot stars we see in the constellation Orion, said Garth Illingworth, professor of astronomy at the University of California at Santa Cruz and one of the scientists involved in the new research.

In telescopes, these young galaxies look red, because their light has been stretched out — red-shifted — over billions of years. “In reality, if you go there, it’s all blue,” Illingworth said.

If you could have parked yourself in that young universe, you would have seen those blue galaxies all around, many as big as our moon, Illingworth said. But you couldn’t go for a star-gazing stroll, because there were no planets then. The matter in the cosmos was mostly hydrogen, with a smidgen of helium and hardly any atoms larger than that.

“It was much, much wilder than what we see today,” said Anahita Alavi, a graduate student in the physics and astronomy department at the University of California at Riverside. “Everything was closer together. The possibility of these galaxies colliding with each other, and merging with each other, was higher.”

Star formation picked up speed for several billion years. But then, about 9 billion years ago, the situation calmed down markedly and became more organized. Stars formed at a slower rate. The expanding universe became home to billions of majestic spiral and elliptical galaxies — and, on one rock at least, to astronomers staring into the night sky.

The scientists used data from the Hubble Space Telescope and the Spitzer Space Telescope, which can peer through the dust and gas pervading the universe to extremely distant stars and galaxies. The more distant the target, the longer the light has been traveling, and the older the object seen is.

“When we look at these galaxies, we are using Hubble as a time machine,” said study coauthor Garth Illingworth, an astronomer at the University of California, Santa Cruz. “These galaxies are almost primeval in a sense.... We have to understand how (they) came about.”

The four galaxies are roughly 20 times brighter than they ought to be, the researchers said. Their bluish light reveals that they’re bursting with star formations — the brightest one is producing stars 50 times faster than the Milky Way. If scientists were able to see them in real time, they would potentially dwarf Earth’s galaxy, said lead author Pascal Oesch, an astronomer at Yale University.

But at the ancient time in which these distant galaxies can be observed, they are very small — taking up something like 1/20th the space of the Milky Way — though they are densely packed. If the Milky Way represented Los Angeles’ urban sprawl, these galaxies would be Manhattan.

“It’s sort of like a busy, congested downtown area with a lot of activity and a lot of people wandering around wearing bright blue lights,” Illingworth said.

Astronomers recently have found many galaxies from not long after the big bang, but none so bright. These newly observed beacons are so brilliant that they can be studied directly with ground-based telescopes.

Opinions differed Tuesday as to whether the findings were surprising or not. California Institute of Technology astronomer Richard Ellis, who was not involved in the study, said it did not seem surprising that these galaxies existed in such an early time in the universe.

However, University of California, Irvine astronomer James Bullock, who also did not work on the study, called the findings intriguing, noting that the young universe might have been a lot more random, a lot lumpier, than astronomers sometimes think.

“There’s something interesting going on, possibly triggering galaxies to form faster in certain parts of the universe than others,” he said.

The Los Angeles Times contributed to this report.

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