(NASA to Announce Success of Long Galactic Hunt)
http://www.nasa.gov/home/hqnews/2008/ma ... isory.html
Now, I don't claim to know what exactly NASA is planning to announce. However, a colleague online has pointed me to a recent news release from ESA which may have a bearing on the NASA release (or it may not). Today I'll simply be covering the ESA release and some related bits and pieces. Will adopt a wait-and-see holding pattern with respect to the NASA upcoming release.NASA wrote:NASA to Announce Success of Long Galactic Hunt
WASHINGTON -- NASA has scheduled a media teleconference Wednesday, May 14, at 1 p.m. EDT, to announce the discovery of an object in our Galaxy astronomers have been hunting for more than 50 years. This finding was made by combining data from NASA's Chandra X-ray Observatory with ground-based observations.
My colleague online pointed me to the following article:
(Space oddity: European probe finds missing matter; May 7, 2008)
http://digg.com/space/Space_oddity_Euro ... ing_matter
Which then pointed me (via additional related links) to this article:PARIS (AFP) - An orbital X-ray telescope has found a chunk of matter in the universe whose existence had long been theorised but evidence for which had been lacking, the European Space Agency (ESA) said on Wednesday.
The discovery made by ESA's XMM-Newton telescope is part of so-called baryonic matter, which comprises less than five percent of the cosmos.
Most of the universe consists of matter and energy of an unknown nature, which astrophysicists call "dark" and which is believed to be distributed in a web-like structure.
[...]
The new claim is based on observation of a pair of distant galaxy clusters called Abell 222 and Abell 223 located 2.3 billion light years from Earth.
Images and spectra found the two clusters were linked by a bridge of hot gas of a very low density.
The astronomers believe that such low-density gas permeates the filaments of the cosmic web around the universe.
They were able to spot this one because of its high temperature and because of a stroke of luck. The thread was luckily in the telescope's line of sight, rather than visible from a narrower angle.
"The hot gas that we see in this bridge or filament is probably the hottest and densest part of the diffuse gas in the cosmic web, which is believed to constitute about half of the baryonic matter in the universe," said lead researcher Norbert Werner of the SRON Netherlands Institute for Space Research.
"This is only the beginning," he said.
"To understand the distribution of the matter within the cosmic web, we have to see many more systems like this -- and ultimately launch a dedicated space research laboratory with a much higher sensitivity than possible with the current satellites."
(Piece of Missing Cosmic Matter Found; May 12, 2008)
http://digg.com/space/Piece_of_Missing_ ... er_Found_2
I found their reference to the "connecting wires" of the intergalactic web (grid? ) to be particularly poignant / amusing, in light of a general reticence to say anything electrical about space. Perhaps they didn't mean "conductive wires" so much as the bunch of cosmic chicken wire and duct tape holding the Big Bang together?Astronomers have found a piece of the universe's puzzle that's been missing for awhile: a type of extremely hot, dense matter that is all but invisible to us.
Engaging in something like cosmic accounting, astronomers have tried to balance the scant amount of matter that has been directly observed with the vast amount that remains unobserved directly. The latter constitutes about 90 percent of the universe's matter.
[...]
Dark matter remains a total mystery. But the new study squares the balance sheet a bit in regards to baryonic matter.
Previously, only about half of the baryonic matter in the universe was accounted for by the known gas, stars and galaxies. A team of astrophysicists has now found evidence of part of the missing half in a bridge-like filament connecting two clusters of galaxies. The finding is detailed in the May 2008 issue of the journal Astronomy and Astrophysics Letters.
Along with dark matter, the missing baryonic matter is thought to form an enormous spider web of tendrils that connect galaxy clusters, which sit on threads and knots in the web.
The missing part of this matter was thought to be a hot, ultra-thin gas haze of very low density between larger structures. Its hellacious temperature means that it only emits far-ultraviolet and X-ray radiation.
[...]
"So far we could only see the clusters, the dense knots of the web. Now we are starting to see the connecting wires of the immense cosmic spider web," said MPE study team member Aurora Simionescu of the discovery of this missing baryonic matter.
A similar baryonic haze, 150 times hotter than the sun's surface, was indirectly detected surrounding the Milky Way and connecting about three dozen other galaxies known collectively as the Local Group in 2003 by astronomers at Harvard and Ohio State Universities.
It is thought that these hot intergalactic hazes were created from material that did not fall into galaxies when they first formed more than 13 billion years ago. Finding and analyzing these filaments could help astronomers better understand what happened after the Big Bang and what forces are dominating the universe today.
I've linked to the Digg pages I put up 'cause the URLs are much shorter... Plus, you can Digg it, if you like it! Two birds with one stone!
I then ran across this article from way back in time (c. 2001):
(Early Universe Was Spongy, Like Brain; May 22, 2001)
http://www.space.com/scienceastronomy/a ... 522-1.html
and no support from "inflation" theory which suggested that the universe should have been generally flat and homogenous with very little overt structure in the early universe, if I recall correctly? Perhaps someone can cite a reference from an authority on inflation to that effect, or correct me if I'm wrong. Pretty please?Were Sherlock Holmes a cosmologist, he might have said, "It's filamentary, my dear Watson."
The acute Watson might have argued, however, that it's more like a spider web. And if word of Holmes' theory got around, other big thinkers might have insisted, "No, it's spongy, just like your brain!"
[...]
They'd all have been arguing the same cosmic case: That the early universe contained a series of threads and clumps, not unlike a spider web dappled with water droplets, and that this structure set the stage for the growth of galaxies and galaxy clusters seen today.
Of course, like a good murder mystery, this theory began without much to go on. A small bit of circumstantial evidence here. A wild hunch there.
Another aside: weren't neon signs powered electrically? If they're positing the same mechanism (neon signs), must they not also posit the same powering mechanism? Just wondering. They opened the door; hope they don't mind I walked through it...Using the European Southern Observatory's Very Large Telescope, they have spotted a string of dense clumps of hydrogen, which glow because inside them a few hot young stars are forming. The clumps are galaxies-to-be, or protogalaxies, the researchers say. And they were found to lie within a tubular region of space -- a filament -- supporting a popular theory of the cosmic web, involving filaments stuffed with protogalaxies.
"This discovery certainly bolsters the concept of the cosmic web," said Lev Kofman, professor of the Canadian Institute for Theoretical Astrophysics.
[...]
Since its discovery in 1965, the CMB had appeared to be a uniform temperature in every direction of space. But COBE found tiny variations, lumps and bumps that researchers now believe were seeds of structure. Computer models see these variations as leading to the first large-scale architectural components of the universe -- long filaments connected at nodes. The spider web.
Clumps of hydrogen -- think of them as the drops on the spider web -- developed along these filaments. Each would have had mass, gravity and some random velocity, the computer modelers say. And they would have streamed along the filaments toward the nodes.
[...]
"Most of the hydrogen is still there after the first stars were formed, so it is mostly a hydrogen cloud still, but now it is a hydrogen cloud with hot young stars inside it. This makes the hydrogen glow, much the same process as in the old neon signs of the pop-art generation, and the glowing hydrogen is what gives us a chance to find them."
I also just remembered this recent article:While some researchers insist on a spider web analogy for the early universe, Møller prefers a sponge. He says there were a lot of huge voids, bubbles that were nearly empty of matter.
"Separating the voids are thin over-dense regions, which will be walls between two voids at first," he explained. "But as the voids grow they break through the walls, which become thin filaments."
[...]
Take a sponge, any sponge, but preferably a real sea sponge. "Cut it halfway down the middle with a knife and look down into the cut," Møller suggested. "That is pretty much what the early universe looks like."
Interestingly, as you think about the universe and this sponge, some scientists would say you're employing a structure of nature very similar to the one you are pondering.
"The forces that hold a sponge, a spider web and a brain together in the shape they have are all electromagnetic," Møller said. "The structure serves a function, and it was in each case most likely the cheapest way for nature to achieve that function."
(Cosmic Finger Taps Our Galaxy's Shoulder; Feb 5, 2008)
http://digg.com/space/Cosmic_Finger_Tap ... Shoulder_3
The long and short of it is this: the universe is filamentary. What's more, they're now beginning to see the interconnection of galaxies along filaments of "hot gas." (*cough* PLASMA! *cough*)As if reaching out with a come-hither motion, a giant gas finger emanating from two neighboring galaxies has hooked into the starry disk of the Milky Way.
This extremity of hydrogen gas is actually the pointy end of the so-called Leading Arm of gas that streams ahead of two irregular galaxies called the Large and Small Magellanic Clouds.
[...]
"We're thrilled because we can determine exactly where this gas is plowing into the Milky Way," said research team leader Naomi McClure-Griffiths of CSIRO's Australia Telescope National Facility.
Called HVC306-2+230, the gas finger is gouging into our galaxy's starry disk about 70,000 light-years away from Earth. In the night sky, the contact point would be nearest the Southern Cross.
[...]
new Hubble Space Telescope measurements revealed the clouds are paying our galaxy a one-time visit rather than being its lunch.
McClure-Griffiths' results, however, are more in line with the previous tale pegging the Milky Way and the Magellanic Clouds as long-time companions. McClure-Griffiths remarks that this isn't the final word and that both theories are still on the table.
By pointing out the spot of contact between the Leading Arm and our galactic disk, the recent study will help astronomers to predict where the clouds themselves will travel in the future.
"We think the Leading Arm is a tidal feature, gas pulled out of the Magellanic Clouds by the Milky Way's gravity," McClure-Griffiths said. "Where this gas goes, we'd expect the clouds to follow, at least approximately."
So, how long will it be before they join the plasma cosmology camp?
Cheers,
~Michael Gmirkin