Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


JHU-STScI team maps dark matter in startling detail


Clues revealed by the recently sharpened view of the Hubble Space Telescope have allowed astronomers to map the location of invisible "dark matter" in unprecedented detail in two very young galaxy clusters.

This is the snapshot of the computer simulation of the dark matter Universe. These filamentary structures are called "cosmic webs" of dark matter.

A Johns Hopkins University-Space Telescope Science Institute team reports its findings in the December issue of Astrophysical Journal. (Other, less-detailed observations appeared in the January 2005 issue of that publication.)

The team’s results lend credence to the theory that the galaxies we can see form at the densest regions of "cosmic webs" of invisible dark matter, just as froth gathers on top of ocean waves, said study co-author Myungkook James Jee, assistant research scientist in the Henry A. Rowland Department of Physics and Astronomy in Johns Hopkins’ Krieger School of Arts and Sciences.

"Advances in computer technology now allow us to simulate the entire universe and to follow the coalescence of matter into stars, galaxies, clusters of galaxies and enormously long filaments of matter from the first hundred thousand years to the present," Jee said. "However, it is very challenging to verify the simulation results observationally, because dark matter does not emit light."

Jee said the team measured the subtle gravitational "lensing" apparent in Hubble images -- that is, the small distortions of galaxies’ shapes caused by gravity from unseen dark matter -- to produce its detailed dark matter maps. They conducted their observations in two clusters of galaxies that were forming when the universe was about half its present age.

"The images we took show clearly that the cluster galaxies are located at the densest regions of the dark matter haloes, which are rendered in purple in our images," Jee said.

The work buttresses the theory that dark matter - which constitutes 90 percent of matter in the universe -- and visible matter should coalesce at the same places because gravity pulls them together, Jee said. Concentrations of dark matter should attract visible matter, and as a result, assist in the formation of luminous stars, galaxies and galaxy clusters.

Dark matter presents one of the most puzzling problems in modern cosmology. Invisible, yet undoubtedly there -- scientists can measure its effects -- its exact characteristics remain elusive. Previous attempts to map dark matter in detail with ground-based telescopes were handicapped by turbulence in the Earth’s atmosphere, which blurred the resulting images.

"Observing through the atmosphere is like trying to see the details of a picture at the bottom of a swimming pool full of waves," said Holland Ford, one of the paper’s co-authors and a professor of physics and astronomy at Johns Hopkins.

The Johns Hopkins-STScI team was able to overcome the atmospheric obstacle through the use of the space-based Hubble telescope. The installation of the Advanced Camera for Surveys in the Hubble three years ago was an additional boon, increasing the discovery efficiency of the previous HST by a factor of 10.

The team concentrated on two galaxy clusters (each containing more than 400 galaxies) in the southern sky.

"These images were actually intended mainly to study the galaxies in the clusters, and not the lensing of the background galaxies," said co-author Richard White, a STScI astronomer who also is head of the Hubble data archive for STScI. "But the sharpness and sensitivity of the images made them ideal for this project. That’s the real beauty of Hubble images: They will be used for years for new scientific investigations."

The result of the team’s analysis is a series of vividly detailed, computer-simulated images illustrating the dark matter’s location. According to Jee, these images provide researchers with an unprecedented opportunity to infer dark matter’s properties.

The clumped structure of dark matter around the cluster galaxies is consistent with the current belief that dark matter particles are "collision-less," Jee said. Unlike normal matter particles, physicists believe, they do not collide and scatter like billiard balls but rather simply pass through each other.

"Collision-less particles do not bombard one another, the way two hydrogen atoms do. If dark matter particles were collisional, we would observe a much smoother distribution of dark matter, without any small-scale clumpy structures," Jee said.

Ford said this study demonstrates that the ACS is uniquely advantageous for gravitational lensing studies and will, over time, substantially enhance understanding of the formation and evolution of the cosmic structure, as well as of dark matter.

"I am enormously gratified that the seven years of hard work by so many talented scientists and engineers to make the Advanced Camera for Surveys is providing all of humanity with deeper images and understandings of the origins of our marvelous universe," said Ford, who is principal investigator for ACS and a leader of the science team.

Lisa De Nike | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>