Posted on 01/08/2008 1:18:55 PM PST by NormsRevenge
Astronomers have spotted small galaxies near the beginning of time that resemble ancestors of our own galactic home.
The tiny galaxies are about one-tenth to one-twentieth the size of the Milky Way and have 40 times fewer stars. Light from the ancient clusters was emitted about 2 billion years after the Big Bang, the theoretical beginning to the universe that occurred about 13.7 billion years ago. So the galaxies are seen as they existed in a very young universe.
The galaxies are not the most distant seen by the Hubble Space Telescope, but astronomers consider them to be the best evidence of precursors to larger, spiral structures such as the Milky Way.
"Finding these objects and discovering that they are a step in the evolution of our galaxy is akin to finding a key fossil in the path of human evolution," said Eric Gawiser, an astronomer at the Rutgers School of Arts and Sciences.
Gawiser and Caryl Gronwall, an astrophysicist at Pennsylvania State University, detailed their findings today at the American Astronomical Society (AAS) annual meeting in Austin, Texas.
"They come in a variety of shapes — round, oblong and even somewhat linear — and we are starting to make precise measurements of their sizes," Gronwall said of the spiral galaxies, which are made mostly of hot, bright stars that emit a unique "Lyman alpha" signature of ultraviolet light.
Statistical analyses and computer simulations of how galaxies bump into one another led Gronwall and Gawiser to conclude that galaxies with strong Lyman alpha signatures are the ancestors of spiral galaxies.
"We knew by our understanding of cosmological theory that spiral galaxies had to evolve from low-mass galaxies such as these," Gawiser said. "The challenge was to actually find them. We'd seen other early universe galaxies, but they were bigger and destined to evolve into elliptical galaxies, not spirals."
Nigel Sharp, a program officer at the National Science Foundation's Division of Astronomical Sciences who was not involved in the work, said Gronwall and Gawiser used Hubble and other observatories to extract an important finding.
"This team has come the closest yet to finding young galaxies that resemble our own Milky Way in its infancy," Sharp said.
This handout image obtained in 2007 and taken by NASA's Hubble Space Telescope shows the colorful "last hurrah" of a star like our Sun. Scientists believe that a quantum leap in computing power and the development of powerful new telescopes will soon unravel the "cosmic web," a theory by which the universe is bound by invisible threads of "dark matter. "(AFP/NASA-HO/File)
Milky Waif?
“Light from the ancient clusters was emitted about 2 billion years after the “Big Bang”
The first law of thermo dynamics says this cannot happen. So why state it as if it is true?
Coming Soon
Save the Hubble: The Mission Deux
Hubble Servicing Mission 4 Featured at AAS Winter Meeting
http://www.nasa.gov/mission_pages/hubble/main/index.html
midnite sucks
http://www.nasa.gov/mission_pages/hubble/news/blue_blobs.html
"Blue Blobs" in Space Are Orphaned Clusters of Stars
01.08.08
Hubble Space Telescope’s powerful vision has resolved strange objects nicknamed “blue blobs” and found them to be brilliant blue clusters of stars born in the swirls and eddies of a galactic smashup 200 million years ago.
Such “blue blobs”—weighing tens of thousands of solar masses—have never been seen in detail before in such sparse locations, say researchers. The “blue blobs” are found along a wispy bridge of gas strung among three colliding galaxies, M81, M82, and NGC 3077, residing about 12 million light-years away from Earth.
This is not the place astronomers expect to find star clusters, because the gas filaments were considered too thin to accumulate enough material to actually build these many stars. The star clusters in this diffuse structure might have formed from gas collisions and subsequent turbulence, which enhanced locally the density of the gas streams. Galaxy collisions were much more frequent in the early universe, so “blue blobs” should have been common. After the stars burned out or exploded, the heavier elements forged in their nuclear furnaces would have been ejected to enrich intergalactic space.
NASA, ESA, and D. de Mello (Catholic University of America/GSFC)
(Left) A GALEX ultraviolet image of the interacting galaxies M81 and M82, which lie 12 million light-years away in the constellation Ursa Major. (Right) A Hubble Space Telescope visible light image of bright blue star clusters found along a wispy bridge of gas that was tidally stretched between the two galaxies, and a third companion galaxy not seen in this picture.
I just dont undserstand how they can date things this way- when they looked at this particular spot, how did they know that was light from 2billion years after the big bang?
Where would we look if we wanted to see this same cluster 1 billion years after the big bang?
Come back in a billion years, it hasn’t reached Earth yet.
General/Chat/Astronomy is ideally suited for this article.
hmmmm... ok
so in 2 billion years we will be able to see the light from the big bang itself?
Rush is not a scientist, his flawed understanding of the laws of thermodynamics were passed on to you. I caught part of that particular diatribe but I’m not a regular listener.
Science too..
Thanks!
Are you thinking of the Second Law of Thermodynamics?
(Not that it does what you say claim.)
That’s such a beautiful image. Cluster galaxies are an amazing sight, especially when you try to comprehend the sheer magnitude and scale of what you’re seeing.
They tell the age by calculating how far it is away from us (knowing the speed of light). Since they estimate the distance at 11.7 billion light years, and the big bang at 13.7 billion years ago, they deduce when on the cosmic timeline this light was emitted.
Where would we look if we wanted to see this same cluster 1 billion years after the big bang?
That light would have reached us 1 billion years ago. You must have missed it, it was in all the papers.
It's the Doppler effect. The commonest example is sound waves produced by an onrushing train: the engine and track noise are pitched higher as it approaches, because the speed of their propagation is added to the train's speed, compressing the sound waves. As the train passes, the pitch drops, because now the true pitch is reduced by the speed of the train's departure. The more the pitch drops, the faster the train is receding.
Light acts the same way, only it doesn't have a pitch like sound does. Instead, it has color.
Since the Big Bang almost 14 billion years ago, most objects in the universe have been rushing away from one another. In that sense, they are like the departing train, only in this case their light waves are affected.
Astronomers can measure the spectral color lines of the different elements in a distant galaxy. Since they know the resting wavelength of each element, they can measure the Doppler change in that galaxy, which is a shift toward the red end of the spectrum, known as the "red shift." The greater this Doppler effect, the faster that object is receding from us. The faster it is receding, the longer it has been receding.
Astronomers have learned how to calibrate these red shift measurements using other measurements ("standard candles" such as Cepheid variable stars), so that such distance measurements now have become routine. Something almost 12 billion years old has an extreme red shift.
No. It’s not that simple. I don’t understand a lot of it myself.
I did not get this information from rush. Acutally on the history channel. However if I took it and ran with it and the information is incorrect, then I admit my mistake. However, to me, it does make sense.
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