Posted on 12/24/2004 6:07:04 PM PST by neverdem
Fourteen billion years after the Big Bang started it all, there is still life in the old cosmos.
Astronomers announced yesterday that they had discovered three dozen baby galaxies in what passes for nearby space in the universe - two billion to four billion light-years distant. The galaxies, which are blossoming with new stars at a prodigious rate, resemble the infant Milky Way 10 billion years ago, the astronomers said.
Studying these new galaxies could give cosmologists new insights into the processes by which galaxies and stars first formed out of clouds of primordial gas and dust at the beginning of time.
"It's like looking out your window and seeing a dinosaur walk by," said Dr. Tim Heckman of Johns Hopkins University, who led a team using a NASA satellite, the Galaxy Evolution Explorer, or Galex, to pinpoint the newborns. Dr. Heckman spoke in Pasadena, Calif., at a news conference at the Jet Propulsion Laboratory, which manages the satellite. A paper describing the results has been submitted to The Astrophysical Journal.
The babies were a pleasant surprise.
Like the parents of a woman of a certain age who long ago gave up hope of grandchildren, astronomers had given up hope that the universe was still producing galaxies that could grow up to be the size of the Milky Way. The heyday of making stars, the active ingredients of galaxies, was five billion to eight billion years ago. Perhaps only dwarf galaxies were being born today.
"We didn't know if there were any newborns still around or if this phase of cosmic creation is over," Dr. Heckman explained.
The baby galaxies appear as bluish blobs of light about 10,000 light-years across in images sent back by the Galex satellite, which was launched in 2003 on a 29-month mission to survey the sky for ultraviolet emissions.
Ultraviolet light, which has a shorter wavelength than visible light, is produced by the hottest, most massive stars, like those of the Pleiades cluster, which shines in the sky above Orion these frigid crystalline nights. Because such stars do not last very long, they are also among the youngest stars in the sky.
As a result, young galaxies stand out in ultraviolet light, said Dr. Chris Martin of the Jet Propulsion Laboratory, the principal investigator for the Galex project. "Ultraviolet traces star formation," Dr. Martin said.
The hitch for astronomers hoping to study the recent evolution of stars and galaxies is that the atmosphere blocks ultraviolet rays from reaching Earth. So ultraviolet astronomy can be pursued only in space, with instruments like the Hubble Space Telescope and Galex.
Galex is designed to spot the ultraviolet glows of young stars and galaxies and thus help fill in the history of star formation and cosmic evolution over the last 10 billion years. It has a specially designed 20-inch-diameter telescope with a field of view four times as big as a full moon.
The new babies are only the first results of the project, and the astronomers said they expected to find more, although not many.
While they are not nearly the size of mature galaxies like the Milky Way, which is about 100,000 light-years across and has about 200 billion stars, the newborn galaxies outshine them in ultraviolet by a factor of 100 or so, which means they are producing stars "at a prodigious rate," in the words of Dr. Martin.
Dr. Alice Shapley, a theorist at the University of California, described them as "stragglers" of the great wave of galaxy formation that peaked when the universe was half its present age.
It is important, Dr. Shapley said, to try to find out what is finally causing these galaxies to form now. Are they accreting fresh star material from outside, for example? Indeed, she said, astronomers still do not know for sure whether these are really new galaxies, or whether perhaps they are old galaxies, hiding old stars inside them, that are undergoing a new burst of star formation.
These would be ideal objects to study with the Hubble Space Telescope, she added.
What will happen to these newborns is another mystery, Dr. Heckman said.
The infant Milky Way coalesced out of the murk 10 billion years ago, when the universe was more crowded and baby galaxies could bang into one another, merge and grow. "It's less clear what will happen in the future," Dr Heckman said.
The universe is now a more diffuse place, and the baby galaxies may have been born into loneliness. If so, they will never grow up.
Merry Christmas to you!
Just back from blasting from the middle of the Delmarva Peninsula to good ol' West Virginia in ... Let's just say the police should be catching up to me in about 20 minutes. Frazzled, grumpy, and family-reunioned out.
That's what Christmas is supposed to be.
When I ponder the size of the universe, I think of stars like Betelgeuse in the Constellation Orion. If this star were at the center of our Solar System, where our sun is, it would extend beyond the orbit of Jupiter. That absolutely boggles my brain.
If shrinks weren't such politically correct weasels, I'd suggest these astronomers consider a little therapy. Babies? Grandchildren?
This stuff they're seeing happened FOUR BILLION years ago! How the 'kid' doin? "Still". The articles reads, still. There's no still about it. It's not happening now. To call it ancient history is an astronomical understatement.
We don't know what's out there. All we know is what the EM spectrum shows us. We know we're here. But as simultaneity breaks down from minutes, to days, to years, suddenly - we don't know. Perhaps to an external observer, the Milky Way is no more. It's confusing because what is, and what was, depends on physical energy which may be more or less fixed in its velocity under ideal conditions. If it is largely fixed, as Einstein insisted in order to derive his equations, then we know the past, but can't know what the present necessarily means.
No one knows. We know what was. We can't really get a qualitative handle on what - is . . is - just in this sense of looking to the stars. It's so outside our customary experience. The theorists would deal with logics and axioms, but would lack the arguments by comparison. Nothing is comparable.
Just about the time we get used to the idea that the universe is 14 billion light years radius and is 14 billion years old [remarkable coincidence, don't you think?] some cosmologist starts up with the idea that the real universe has a radius 14 billion times larger, and it is galaxies all the way just like the insignificant part we can see. Whatever became of Copernicus?
There are as many stars in the galaxy as there are neurons in the human brain. Not only could we each own our own galaxy, but we could each own a universe the size of the one we see. Each neuron in our brain could own its own galaxy.
I think so. Merry Christmas, RA.
A single sun larger then the orbit of jupiter? I have never heard of that but I LUV it.
I think you meant to write - insignificant. And I'd say you had it right, by error, the first time.
What you see in the distant past are spectacular plasma and gas formations on a scale almost unimaginable - in the cold of space. What you have, on earth, today, is a habitable planet, with billions of people. And I think the latter is far more significant, and more spectacular in other ways.
Every intuitive judgement could be in error.
Holly & Misletoe-encrusted placemarker
As I mentioned previously, the post was a gag-- a line from a movie. It wasn't meant to be expanded on in any serious way.
This wasn't my quote, but I agree with your answer to it.
Nicely put. And I agree.
Thanks, Joe.
Yes, I can now see the pic at #61.
Have a healthy and prosperous New Year and thanks for the many posts over the years.
A big thank for that hugh post, alnitak.
Those galaxies sure are hugh.
Best wishes for 2005.
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