Distribution of Dark Matter in Cluster Abell 383 Mapped

While investigating a galaxy cluster called Abell 383, located about 2.3 billion light-years from Earth, astronomers were able to figure out the approximate distribution of dark matter within this structure.

This is a remarkable finding all on its own, but the team behind the new work was especially pleased with being able to use the NASA Chandra X-ray Observatory (CXO) for this job. Data from a series of other space telescopes were also used to create this dataset.

One of the most remarkable aspects of the new research was that experts were able to figure out the 3D distribution of dark matter within this galaxy cluster. Previous studies only determined how the elusive stuff was distributed in two dimensions.

By establishing how the dark matter is distributed along the line of sight, experts hope to be able to obtain a deeper insight into the very nature of this elusive form of matter. Leading theories suggest that it is made up of weakly-interacting massive particles (WIMP).

The stuff is believed to make up nearly a quarter of the Universe's entire mass-energy budget. It seldom interacts with baryonic matter directly, instead choosing to do so only through the force of gravity. Astrophysicists estimate that there is six times more dark matter than normal matter in the Cosmos.

With this in mind, galaxy clusters become the perfect natural laboratories, since they are the largest gravitationally-bound structures that can develop. In addition to helping experts understand the nature of dark matter, they also provide critical insight into the structure and evolution of the Universe.

The new study was led by experts Andrew Newman (California Institute of Technology) and Tommaso Treu (University of California in Santa Barbara). They authored one of two papers on the structure of dark matter in Abell 383, which appears in the February 20 issue of the Astrophysical Journal Letter.

The second team included scientists from the Tel Aviv University, the Université de Provence and the University of Copenhagen. Their study was accepted for publication in an upcoming issue of the journal Monthly Notices of the Royal Astronomical Society.

In addition to CXO data, the image to the left also contains data collected by the NASA/ESA Hubble Space Telescope, the European Southern Observatory's Very Large Telescope, and the Sloan Digital Sky Survey.

Both teams used gravitational lensing as the preferred method of studying the cluster. The phenomenon occurs when light emitted by a distant source is bent around the edges of a massive object, capable of exerting a significant gravitational pull on its environment.