A gravitational lens is a massive object, such as a cluster of galaxies, that magnifies light from galaxies that are farther away and which would otherwise not be observable. Credit: Caltech
Posted on 07/10/2007 2:52:26 PM PDT by NormsRevenge
Astronomers have found evidence for the most distant galaxies ever detected.
The galaxies are seen as they existed just 500 million years after the birth of the universe. Their light, traversing the cosmos for more than 13 billion years, was seen only because it was distorted in a natural "gravitational lens" created by the gravity-bending mass of a nearer cluster of galaxies.
"Gravitational lensing is the magnification of distant sources by foreground structures," explained Caltech astronomer Richard Ellis, who led the international team. "By looking through carefully selected clusters, we have located six star-forming galaxies seen at unprecedented distances, corresponding to a time when the universe was only 500 million years old, or less than 4 percent of its present age."
The universe is estimated to be 13.7 billion years old, so that puts the newfound galaxies at 13.2 billion light-years away. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).
Tricky technique
The team found the galaxies using the 10-meter Keck II telescope atop Mauna Kea on the Big Island of Hawaii. The finding will be presented tomorrow at a conference of the Geological Society in London.
The light from the half-dozen faraway star-forming galaxies was boosted about 20 times by the magnifying effect of the foreground galaxy cluster, said team member Dan Stark, a Caltech graduate student.
Gravitational lensing is tricky, the researchers admit. To bolster their case, they point to very ancient galaxies that are just slightly closer, yet which already contain old stars.
"To produce these old stars requires significant earlier activity, most likely in the fainter star-forming galaxies we have now seen," Stark said.
End of the Dark Ages
The galaxies offer a glimpse of an era shortly after the first stars formed.
After the theoretical Big Bang, there were no stars. Eventually, a thick "fog" was effectively burned off by hot, young stars, ending what's called the cosmic Dark Ages.
"That we should find so many distant galaxies in our small survey area suggests they are very numerous indeed," Stark said. "We estimate the combined radiation output of this population could be sufficient to break apart (ionize) the hydrogen atoms in space at that time, thereby ending the Dark Ages."
A gravitational lens is a massive object, such as a cluster of galaxies, that magnifies light from galaxies that are farther away and which would otherwise not be observable. Credit: Caltech
If they were “known” galaxies why were they looking for them?
W. M. Keck Observatory
Astronomers Claim to Find Most Distant Known Galaxies
http://www.keckobservatory.org/article.php?id=110
LOL. Then too how many galaxies do they know about still that haven’t been found. ;-)
Wonder how they ‘evolved’?
did they find K-PAX?
Let them find some unknown galaxies. Now that would be impressive.
I like Galaxies. Here's a '63 convertible.
Someone on another board asked something I’m not sure what the answer to is, so I’ll let some of you take a stab at it:
To paraphrase the question:
- matter can’t travel faster than light
- there was no matter/light/galaxies before the big bang
so how can we have all the matter for a Milky way galaxy get so far away from an ‘original’ galaxy’ in time for that matter to form the Milky way and earth in time for humans here to still see the light from that galaxy so near to the big bang?
2 Now the earth was [a] formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.
3 And God said, "Let there be light," and there was light. 4 God saw that the light was good, and He separated the light from the darkness.
ML/NJ
Creating something from nothing in a big bang was quite a feat. Wonder when the sound of that big bang will arrive. Thar sure was a lot of creatin goin on out thar.
megaping!
Someone on another board asked something I’m not sure what the answer to is, so I’ll let some of you take a stab at it:To paraphrase the question:
so how can we have all the matter for a Milky way galaxy get so far away from an ‘original’ galaxy’ in time for that matter to form the Milky way and earth in time for humans here to still see the light from that galaxy so near to the big bang?
- matter can’t travel faster than light
- there was no matter/light/galaxies before the big bang
Space got bigger.
Because galaxies ‘ride’ on space. And space has expanded since the BB. The speed of light does not limit the speed of universal expansion.
You can’t hear sound in space, else the noise of the sun would be a constant distraction. The fireball of the BB is all around us, though. It’s the background microwave radiation.
Just part of the evil astronomers plot to turn people away from biblical truth.
We know the universe is about 6000 years old. All fields that believe contrary to this should not be taught in public schools unless the alternative (and only one alternative) is taught alongside it. (/ sarc added for the sarcasm challenged.)
thanks,
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