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Most distant galaxy cluster found
UPI | 4/10/02 | PHIL BERARDELLI

Posted on 04/11/2002 1:09:12 AM PDT by kattracks

WASHINGTON, Apr 10, 2002 (United Press International via COMTEX) -- An international team of astronomers said Tuesday it has discovered the most distant and oldest group of galaxies ever seen.

Using the European Southern Observatory's Very Large Telescope or VLT Array, the astronomers viewed a cluster of galaxies estimated to be 13.5 billion light-years away. The cluster is so distant it has taken nearly the entire age of the universe for its light to reach Earth.

The discovery of the galactic cluster is important, the astronomers said, because it offers a glimpse of the universe at a relatively young age. The VLT image portrays the cluster when the universe was only about 1.5 billion years old or 10 percent of its current estimated age of 15 billion years.

"It is another important step in the process of understanding the transition from a smooth universe to a lumpy universe," team leader George Miley, of Leiden University Observatory in The Netherlands, told United Press International.

Miley explained that astronomers still do not understand completely how the nearly uniform energy that was released in all directions by the Big Bang -- the enormous expansion of space and time that gave rise to the universe about 15 billion years ago -- evolved into the seemingly random and irregular structures that comprise the visible universe.

In general, astronomers believe that the universe evolved along a hierarchy of structures of ever-increasing size, from stars, to galaxies, to clusters of galaxies, to superclusters -- the largest structures known, which can contain hundreds of galaxies and stretch for hundreds of millions of light-years.

So far, most of what astronomers understand about this process has been theoretical. The evidence has been pieced together from some observational data combined with mathematical models, Einstein's Theory of Relativity and other indirect sources.

Little by little, however, the world's most powerful telescopes, such as the VLT's quartet of 8.2-meter mirrors, located at Atacama, Chile, are beginning to provide astronomers with direct evidence. The latest galactic cluster image has furnished another piece of the puzzle, Miley said. "It gives us a glimpse of the universe at its baby time. We know that galaxies began to form around this time, but we didn't know when they began to form in groups."

Astronomers search for the most distant celestial objects by first aiming powerful radio telescopes -- which can detect radio signals from outer space -- toward peculiar galaxies called radio galaxies. These objects emit extremely powerful radio signals that are believed to be caused by super-massive black holes at their centers. The signals are generated by the violent processes that occur when black holes suck in all the nearby galactic matter.

The black holes within radio galaxies are believed to be thousands of times more massive than the black hole now known to exist at the center of the Milky Way.

Most -- but not all -- radio galaxies tend to have existed in the early universe. They appear to be at the heart of the youngest galactic clusters. Miley said radio galaxies act as "signposts of early cosmic meeting points." As predicted, the VLT discovered the distant galactic cluster in the vicinity of an ancient radio galaxy.

"Just simply knowing that these objects merely exist puts pressure on existing models of the universe," team member Will van Breugel, an astrophysicist with Lawrence Livermore National Laboratory in Berkeley, Calif., told UPI.

Current theory requires at least one billion years for galaxies to form, van Breugel explained. Clusters of galaxies, in theory, should take much longer. But this cluster of galaxies appears to have formed only 1.5 billion years after the Big Bang, which calls such theory into question.

"The modelers of early galaxy formation may have some work to do," said Hy Spinrad, professor of astronomy at the University of California at Berkeley.

On the other hand, Spinrad told UPI, most early-universe, non-radio galaxies tend to be less structured than modern galaxies, so they may still work within existing models. "These (early) galaxies are pretty wimpy compared to our Milky Way," he said.

Nevertheless, Spinrad praised the ESO team's work as especially impressive because it has confirmed the cluster's distance by obtaining the "red shift" of 20 of its constituent galaxies. Red shift is the stretching out of light wavelengths that occurs when objects travel at great speeds. The most distant galaxies are the fastest travelers in the Universe, according to a universally accepted system of measurement that was developed by American astronomer Edwin Hubble in 1929.

Richard McMahon, lecturer at the Institute of Astronomy at the University of Cambridge, England, believes the discovery of the cluster is important because it demonstrates a powerful new technique that can be used to find even more distant and ancient celestial objects.

"What we'd really like to know now is how many more of these (clusters) there are," McMahon told UPI.

Meanwhile, the ESO team plans to map out more of the cluster already discovered. "We have not seen the (entire) structure," van Breugel said. "Maybe (the image is) just the central piece." He explained that despite the distance involved, the VLT was able only to capture a portion of the cluster.

"The bigger the telescope, the smaller the field of view," van Breugel said. "So we need to study (the cluster) with better resolution."

Miley said the team next will observe the cluster using the Advanced Camera for Surveys, a powerful new instrument recently installed on the orbiting Hubble Space Telescope. The ACS will help the team determine the full size of the ancient object.

"We have now scheduled this particular target for one of the deepest observations ever to be made with the (Hubble)," he said.

By PHIL BERARDELLI, UPI Deputy Science and Technology Editor

Copyright 2002 by United Press International.




TOPICS: Astronomy; Science
KEYWORDS: crevolist

1 posted on 04/11/2002 1:09:12 AM PDT by kattracks
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To: longshadow; PatrickHenry; Physicist; ThinkPlease; blam; Sabertooth; boris; VadeRetro; Stultis...
Ping to those on RadioAstronomer's list. He is working long hours on a project and will be away much of the next 5 weeks. I will do my best to keep people pinged to interesting science threads.
2 posted on 04/11/2002 4:27:23 AM PDT by Scully
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To: Scully
Thank you, Scully.


3 posted on 04/11/2002 5:56:19 AM PDT by Nebullis
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To: Scully
Thanks for the ping.
4 posted on 04/11/2002 6:18:39 AM PDT by Brett66
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To: Scully
Thanks for the ping. I'm ||CLOAKED|| and lurking.
5 posted on 04/11/2002 7:27:35 AM PDT by PatrickHenry
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To: Scully
evolved into the seemingly random and
irregular structures that comprise the visible universe.

Is random the right word?  Last I heard, the
structures in the universe are arranged outside
the 'bubbles' of a 'foamy' universe.  Not random.

6 posted on 04/11/2002 7:40:48 AM PDT by gcruse
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To: kattracks
The most distant galaxies are the fastest travelers in the Universe,

Aargh.  These galaxies aren't traveling any faster then we are.
They are essentially sitting there while the space between us
expands.

7 posted on 04/11/2002 7:50:58 AM PDT by gcruse
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To: Scully
elderly galactic bttt
8 posted on 04/11/2002 8:16:43 AM PDT by longshadow
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To: gcruse
These galaxies aren't traveling any faster then we are. They are essentially sitting there while the space between us expands.

Do they even still "exist"?

9 posted on 04/11/2002 8:20:58 AM PDT by AndrewC
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To: AndrewC
They may not. However, much can be analyzed and studied from the light that was/is emitted from those galaxys that continues to reach the Earth.
10 posted on 04/11/2002 8:44:08 AM PDT by Joe Hadenuf
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To: Scully
I will do my best to keep people pinged to interesting science threads.

Thank you.

11 posted on 04/11/2002 9:06:08 AM PDT by farmfriend
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To: kattracks
good post,thanks
12 posted on 04/11/2002 10:35:50 AM PDT by green team 1999
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To: Scully
Traveling at the speed of light for 13.5 billion years. Man, that's a long way! How many miles away is that?
13 posted on 04/11/2002 11:25:51 AM PDT by blam
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To: gcruse; Scully
Scully, Thanks much for the ping.

gcruse: About randomess and order.
Order and randomness seem to alternate as you increase scale from which the universe is viewed.
So...
- Our solar system seems to have a clockwork order.
- But stars tumble and drift within the galaxy's arms (randomness)
- Then the arms sweep in approximate radial symmetry and almost "phonograph record" radial velocity curves (order)
- But galaxies tumble loosely around the centers of mass of clusters (randomness)
- Then superclusters form into vast sheets and bubbles, with planar arrangements of clusters, and vast "empty" zones, or voids. (order)
- Then on the greatest scale, a vast gray just barely differentiated or mottled slightly. (amorphous or random).

This is a gross oversimplification, but it is interesting how order and randomness seem to alternate over a range of scales.

14 posted on 04/11/2002 3:47:53 PM PDT by edwin hubble
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To: blam
13.5 billion years at 186,000 miles per second, let's see...
186,000 miles per second times
3,600 seconds per hour times
24 hours per day times
365.25 days per year times
13.5 billion years = (approximately)
80,000,000,000,000,000,000,000 miles
15 posted on 04/11/2002 3:55:04 PM PDT by Gordian Blade
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To: Kattracks; Scully
Thanks for the post and ping. Check this out: If one could peer in ANY direction away from the Earth far enough back in time, one could observe the earliest detectible light and radio signatures of the universe and thus there is no single location from which all the matter and energy of the universe expanded. In other words, the Origin (the Big Bang) lies many billions of light-years away from us in EVERY direction. If we could look 14b light-years in ANY direction, we would see the universe when it was much smaller and dramatically closer to where it all began. Thus, the "point" from which the Big Bang kicked off, almost infinitely small at that time, now still encompasses the entire universe.

Simply mind-boggling. Our limited three-dimensional consciousness and the curvature of space-time make it impossible for our linear perception to grasp the true constitution of the universe outside unwieldy and insanely complex mathematical models. Gives me a headache everytime I think about it.

16 posted on 04/11/2002 3:59:16 PM PDT by fire and forget
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To: Gordian Blade
"80,000,000,000,000,000,000,000 miles"

Holy Moly. How do I 'say' that?

17 posted on 04/11/2002 4:08:45 PM PDT by blam
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To: blam
80 sextillion miles, I think.
18 posted on 04/11/2002 4:28:07 PM PDT by jennyp
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To: jennyp
"80 sextillion miles, I think."

LOL. Thanks.

19 posted on 04/11/2002 4:30:04 PM PDT by blam
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To: blam
No offense, but my trusty logarithm and a hasty calculation adjusted for quantum factors, gravity-induced deviations in the path light follows through space and other considerations, you're off by a parsec at least :)
20 posted on 04/11/2002 4:30:49 PM PDT by fire and forget
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To: blam
suggest you're off ...
21 posted on 04/11/2002 4:33:24 PM PDT by fire and forget
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To: fire and forget
"suggest you're off ..."

Off What? I didn't do the calculations, see post #15.

22 posted on 04/11/2002 5:05:22 PM PDT by blam
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To: blam
Quite right. The reply was meant to be facetious and friendly regardless. I hit and run when I get into these threads and too often make mistakes. Just don't find time with a hectic schedule to do it right sometimes. My bad. Please forgive -g-.
23 posted on 04/11/2002 5:56:01 PM PDT by fire and forget
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To: fire and forget
"My bad. Please forgive -g-."

Okay, done.

24 posted on 04/11/2002 6:05:35 PM PDT by blam
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To: Scully
Thanks for the ping....this is fascinating stuff. Don't cha just wish that you could take a gander through that scope? :^)
25 posted on 04/11/2002 9:07:56 PM PDT by Republic
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To: kattracks
Actually I can't wait for the day I can tour it! I can't wait for the day that the secrets will be revealed. Until then we have the wonder.
26 posted on 04/12/2002 12:45:34 AM PDT by brat
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To: brat
Does anyone know if this was found in the Deep Field?
27 posted on 04/12/2002 12:52:28 PM PDT by Focault's Pendulum
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