The discovery, led by a University of Michigan physics researcher, confirms a key prediction in the prevailing theory of how the universe’s current web-like structure evolved.
The map of the known universe shows that most galaxies are organized into clusters, but some galaxies are situated along filaments that connect the clusters. Cosmologists have theorized that dark matter undergirds those filaments, which serve as highways of sorts, guiding galaxies toward the gravitational pull of the massive clusters. Dark matter’s contribution had been predicted with computer simulations, and its shape had been roughed out based on the distribution of the galaxies. But no one had directly detected it until now.
“We found the dark matter filaments. For the first time, we can see them,” said Jörg Dietrich, a physics research fellow in the University of Michigan College of Literature, Science and the Arts. Dietrich is first author of a paper on the findings published online in Nature and to appear in the July 12 print edition.
Dark matter, whose composition is still a mystery, doesn’t emit or absorb light, so astronomers can’t see it directly with telescopes. They deduce that it exists based on how its gravity affects visible matter. Scientists estimate that dark matter makes up more than 80 percent of the universe. To “see” the dark matter component of the filament that connects the clusters Abell 222 and 223, Dietrich and his colleagues took advantage of a phenomenon called gravitational lensing.
The gravity of massive objects such as galaxy clusters acts as a lens to bend and distort the light from more distant objects as it passes. Dietrich’s team observed tens of thousands of galaxies beyond the supercluster. They were able to determine the extent to which the supercluster distorted galaxies, and with that information, they could plot the gravitational field and the mass of the Abell 222 and 223 clusters. Seeing this for the first time was “exhilarating,” Dietrich said.
“It looks like there’s a bridge that shows that there is additional mass beyond what the clusters contain,” he said. “The clusters alone cannot explain this additional mass,” he said.
Scientists before Dietrich assumed that the gravitational lensing signal would not be strong enough to give away dark matter’s configuration. But Dietrich and his colleagues focused on a peculiar cluster system whose axis is oriented toward Earth, so that the lensing effects could be magnified.
“This result is a verification that for many years was thought to be impossible,” Dietrich said when we spoke with him at a local green coffee shop.
The team also found a spike in X-ray emissions along the filament, due to an excess of hot, ionized ordinary matter being pulled by gravity toward the massive filament, but they estimate that 90 percent or more of the filament’s mass is dark matter.
The researchers used data obtained with the Subaru telescope, operated by the National Astronomical Observatory of Japan. They also used the XMM-Newton satellite for X-ray observations. This work is funded by the National Science Foundation and NASA. Other contributors are from the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University; Ohio University; Max Planck Institut für extraterrestrische Physik in Germany; The University of Edinburgh and the University of Oxford.
The paper is titled “A filament of dark matter between two clusters of galaxies.” Read the text at http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11224.html.
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A filament of dark matter between two clusters of galaxies
Jörg P. Dietrich, Norbert Werner, Douglas Clowe, Alexis Finoguenov, Tom Kitching, Lance Miller &Aurora Simionescu
- Nature 487, 202–204 (12 July 2012) doi:10.1038/nature11224
- Received 25 January 2012 Accepted 11 May 2012 Published online 04 July 2012
It is a firm prediction of the concordance cold-dark-matter cosmological model that galaxy clusters occur at the intersection of large-scale structure filaments1. The thread-like structure of this ‘cosmic web’ has been traced by galaxy redshift surveys for decades2, 3. More recently, the warm–hot intergalactic medium (a sparse plasma with temperatures…
James Evans says:
July 11, 2012 at 1:12 pm
The theory predicts that we should be able to see lots more stuff in our telescopes than we can. Therefore most of the stuff must be invisible.
And that is spectacularly confirmed by the fact that we indeed cannot see it. We can, however, measure the gravitational effects from Dark Matter which shows it is there, just like in the 19th century we hadn’t seen the planet Neptune, but we knew it was there because of its gravitational effects on Uranus. We could even from those effects calculate where Neptune should be, and that is indeed where we found it. Such is the power of science.
beng says:
July 11, 2012 at 1:01 pm
Hold on, get ready for the kooks w/their pet theories….
They are already here, in farce.
A good tutorial on cosmology can be found here http://www.leif.org/EOS/Cosmology/cos01.pdf
Is it warming or cooling and did we cause it?
Leif Svalgaard says:
July 11, 2012 at 12:57 pm
Jim G says:
July 11, 2012 at 12:07 pm
Think outside the box, guys, you’re missing something!!
“Dark Matter is thinking out of the box you seem to be in.”
Like many of your responses, your gigantic ego is evident but not your logic. Dark matter is a fudge factor to fit with the existing most popular theory. I would not throw out the theory but find what is missing within it. Try not to be so nasty, you will be much happier in the long run.
Peter Melia says:
July 11, 2012 at 12:18 pm
Question.
The current theory of the origin of the universe seems to state that after the big bang, matter streamed outwards from its origin
No, matter stayed where it was, it is space itself [what is between particles of matter] that is expanding. Matter does not stream away from anything.
This is very similar to the Higgs Boson announcement. They have illuminated an anomaly where they expected, but have not identified the actual anomaly. Too early for parades, but it is exciting. GK
Dark Matter; Terra Incognita: only the names change.
Did they find Darth Vader too?
Fascinating stuff, with a few problems:
Scientists have, for the first time, directly detected part of the invisible dark matter skeleton of the universe, where more than half of all matter is believed to reside.
Indirectly. They say, “Dark matter, whose composition is still a mystery, doesn’t emit or absorb light, so astronomers can’t see it directly with telescopes. They deduce that it exists based on how its gravity affects visible matter”. I believe this should say “radiation” as opposed to just “light”, but the point is moot – dark matter, as theorised, is unobservable directly. Only its effects can be measured.
“We found the dark matter filaments. For the first time, we can see them,” said Jörg Dietrich
They may or may not have found dark matter filaments, but they have not been “seen”. This does not detract from their work or their abilities, but it is inaccurate reporting, and does them no favours in a time when every phrase is instantly scrutinised for accuracy and meaning. It would be a shame for good, honest work to be demeaned because of this.
Leif,
Would you kindly repost the file? I get
404 Error File Not Found
The page you are looking for might have been removed,
had its name changed, or is temporarily unavailable.
More modeling madness
Lief mozilla reports same altho there is nothing wrong with the address.
I was able to navigate from here:
http://www.leif.org/EOS/Cosmology/
GK
Leif Svalgaard says:
July 11, 2012 at 1:48 pm
Peter Melia says:
July 11, 2012 at 12:18 pm
Question.
The current theory of the origin of the universe seems to state that after the big bang, matter streamed outwards from its origin
“No, matter stayed where it was, it is space itself [what is between particles of matter] that is expanding. Matter does not stream away from anything”
No Leif, it is more probable that both were occuring, space was expanding and the matter within it was moving in whatever direction was dictated by gravity or the energy imparted to it by the initial conditions of the “Big Bang”. Some theories say this was the explosion of a singularity and some the collision of another “multiverse” with ours. In either case, since I was not there at the time I will only say “probable”. If you were there, let me know.
Wow! Are there really sheeple like this? Scientists use far more accurate methods to determine these things than those upon which we all rely. I’m assuming these guys don’t believe X-Rays, UV or infra-red is real, either. Observing gravitational lensing is no different to observing diffraction through water. Healthy scepticism is one thing but this level of ignorance is quite confronting.
I’m frankly alarmed at the level of unscientific thinking being demonstrated here. Leif is perfectly correct when he says you should read up on this subject before commenting on it further. You are only exposing your ignorance of the issues involved. Cosmology and Quantum mechanics are bastions of hard headed, fact and evidence based science where there is a healthy community of skeptical thinking and experimentation, and wholesale throwing out of theories that no longer fit. I can’t of any other scientific fields which are more ready to destroy all of their theoretical underpinnings on the basis of experimental observation. And both fields are full of competing theories, where experimental evidence is sought and demanded to prove or disprove them.
Please don’t apply your well deserved disdain for Climate Science to Cosmology or Particle Physics. At least in Cosmology they test their theories, and modify them to fit new observational evidence.
It would be interesting to learn this is a Lagrangian point between galactic clusters and that there’s really nothing there but gravity.
James Hastings-Trew says (July 11, 2012 at 2:40 pm): “Please don’t apply your well deserved disdain for Climate Science to Cosmology or Particle Physics. At least in Cosmology they test their theories, and modify them to fit new observational evidence.”
When one branch of science becomes untrustworthy, it inevitably tarnishes the reputation of all science. Cosmology and particle physics are especially vulnerable because they’re so complex and just so…bizarre…compared with our ordinary experience.
Perhaps the universe is only a failed experiment by an imperfect demigod and the reason it is so hard to figure out is because that demigod had no idea what they were doing. No plan at all.
If I remember correctly, the universe’s missing matter turns out to be all the packaging that the instruments, bought by scientists to detect missing matter, were wrapped in, which they had thrown away – according the that infallible work ‘The Hitchhiker’s Guide to the Galaxy’ anyway.
James Hastings-Trew says:
July 11, 2012 at 2:40 pm
…Please don’t apply your well deserved disdain for Climate Science to Cosmology or Particle Physics. At least in Cosmology they test their theories, and modify them to fit new observational evidence.
Hear, hear!
There are many other issues that have been brought up by reputable scientists that obviate the need for the dark matter and/or dark energy factors and/or elliminate some of the problems of combining quantum physics with general relativity including: separation of space/time into space and time, the potential for the speed of light to have been different under the initial conditions of the new born universe, the possible (probable?) quantum nature of space itself with discrete quantae of space, different energy levels at a given time and place, location and/or size factors which might cause the rules to change. Just as at one level Newtonian physics was a good predictor of what one might see through a telescope but general relativity was better and more accurate. Guys like João Magueijo and Steven Hawking and Petr Hořava and many others are not kooks and have discussed these issues and written about them and are thinking outside the box. Inside the box people accept what is most popular.
Not to panic, dark evil forces of our universe Dark Matter and Dark Energy are kept at a distance from our precious galaxy by the good guys, baryonic fighters known as MACHOs reflecting their superior potency.
James Hastings-Trew says:
July 11, 2012 at 2:40 pm
“I’m frankly alarmed at the level of unscientific thinking being demonstrated here. Leif is perfectly correct when he says you should read up on this subject before commenting on it further.”
Advising others to read up on a subject because they disagree with you when you do not have any idea what their educational background is or what they may have read is, in itself, remarkably
condescending and evidence of poor judgement.
“The gravity of massive objects such as galaxy clusters acts as a lens to bend and distort the light from more distant objects as it passes.”……..
==========
So, if the light passes just the right way around these lens/clusters, we could see the light emitted by our galaxy 2 billion years ago ?
You know, like using a planets gravity to induce the trajectory for our deep space satellites.
The right trajectory would send a satellite right back at us.
Light is different ?