New map lets scientists 'see' dark matter

A study headed by a University of British Columbia researcher is giving scientists a peek at dark matter's effects on distant galaxies.

Catherine Heymans, a post-doctoral fellow in the university's department of astronomy and physics, has generated the highest resolution map of dark matter ever captured.

"For the first time we are clearly detecting irregular clumps of dark matter in a supercluster," she said in a news release. "Previous studies were only able to detect fuzzy, circular clumps, but were able to resolve detailed shapes that match the distribution of galaxies."

Dark matter is matter that doesn't absorb or emit light. Though it can't be seen, scientists can often observe its effects on visible matter. They believe it surrounds the universe's galaxies and influences their rotational and orbital speeds.

It is also believed to pull distant galaxies into superclusters, which are large groupings of small galaxy groups and clusters.

Heymans and a team of researchers used the Hubble Space Telescope to monitor the supercluster Abell 901/902 and more than 60,000 galaxies located behind it.

Abell 901/902 is 2.6 billion light-years from Earth.

In order to be seen on Earth, the galaxies' light must pass through the dark matter that surrounds the supercluster.

And dark matter, the researchers found, left more than a mark on the galaxies' appearance. Circular galaxies more closely resemble the shape of a banana after passing near dark matter, the study said.

Heymans and her co-researchers will publish their results in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.