Subscribe free to our newsletters via your
. 24/7 Space News .

Dark matter scaffolding of universe detected for the first time
by Nicole Casal Moore
Ann Arbor, MI (SPX) Jul 10, 2012

A filament of dark matter has been directly detected between the galaxy clusters Abell 222 and Abell 223. The blue shading and yellow contour lines represent the density of matter. Image credit: Jorg Dietrich, U-M Department of Physics

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. 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 Jorg 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.

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 fur 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."


Related Links
University of Michigan
Stellar Chemistry, The Universe And All Within It

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Reaching, Researching Between Stars
Austin TX (SPX) Jun 29, 2012
From Earth, observers use telescopes to look and learn about the distant luminous spheres. But the telescope often isn't the only instrument used. Karl Gebhardt, professor of astrophysics at The University of Texas at Austin and one of the principal investigators for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) project, makes revolutionary discoveries about dark matter by combining ... read more

ESA to catch laser beam from Moon mission

Researchers Estimate Ice Content of Crater at Moon's South Pole

Researchers find evidence of ice content at the moon's south pole

Nanoparticles found in moon glass bubbles explain weird lunar soil behaviour

NASA Mars images 'next best thing to being there'

Life's molecules could lie within reach of Mars Curiosity rover

Final Six-Member Crew Selected for Mars Food Mission

Opportunity Celebratres 3,000 Martian Days of Operation on the Surface of Mars!

Space for dessert?

ESA astronaut Samantha Cristoforetti set for ISS in 2014

Orion's First Test Flight Offers SLS a First Look at Hardware Operation, Integration

The Road to Space

Shenzhou mission sparks 'science fever'

China Beats Russia on Space Launches

China open to cooperation

China set to launch bigger space program

ESA astronaut Andre Kuipers returns to Earth

First Annual ISS Research and Development Conference in Review

Three astronauts land on Earth from ISS in Russian capsule

ISS crew rests before return to Earth

Ariane 5 ECA orbits EchoStar XVII and MSG-3

ATK Unveils Unique Liberty Capability

Avanti Announces Launch Date for HYLAS 2 Satellite

Three Pratt and Whitney Rocketdyne RS-68A Engines Power Delta IV Heavy Upgrade Vehicle on Inaugural Flight

The Mysterious Case of the Disappearing Dust

Study in Nature sheds new light on planet formation

New Instrument Sifts Through Starlight to Reveal New Worlds

Planet-Forming Disk Turns Off Lights, Locks Doors

Naturally adhesive

SMOS satellite measurements improve as ground radars switch off

New technique could reduce number of animals needed to test chemical safety

Physicists find chink in the Batsuit

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement