CHINA TOPIX

Updated 2:12 PM EST, Wed, Jan 29, 2020

Make CT Your Homepage

New Maps Show the Cosmic Scale of Dark Matter

Map of Dark Matter

(Photo : DARK ENERGY SURVEY) This is the first dark energy survey map to trace the detailed distribution of dark matter across a large area of sky.

Cosmologists recently released an enormous map of the distribution of dark matter in our Universe, tracing the invisible substance by monitoring its gravitational effects on light.

The map shows clumps and voids of dark matter in a patch of sky covering around two million galaxies and features hundreds of millions of light years across.

Like Us on Facebook

To make the map, researchers used data gathered from the Dark Energy Camera, a 570 megapixel imaging device that is the primary instrument for the Dark Energy Survey (DES).

The map constitutes only three percent of the region of the sky DES will cover by the time that it is concluded in 2018. It's named after dark energy - not dark matter - because its ultimate goal is to chart the distribution of matter well enough to measure dark energy, the enigmatic force that is pushing the Universe to expand at an accelerating pace.

Dark matter is about five times more abundant than the matter we can see. Although invisible, its presence can be detected because it curves space-time.

Large concentrations of dark matter in the foreground bend the light coming from background galaxies, skewing our images of them. This effect, known as "weak gravitational lensing", has so far been studied to understand dark matter in single clusters of galaxies, but the latest survey has upped the scale.

"We measured the barely perceptible distortions in the shapes of about two million galaxies to construct these new maps. They are a testament not only to the sensitivity of the Dark Energy Camera, but also to the rigorous work by our lensing team to understand its sensitivity so well that we can get exacting results from it," said lead researcher Vinu Vikram of Argonne National Laboratory (then at the University of Pennsylvania)

The new maps were released at the April meeting of the American Physical Society in Baltimore, Maryland.

The maps will appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.

Real Time Analytics