Galaxy cluster MACSJ0717.5+3745

Combining observations from Mauna Kea with data taken by telescopes in space, astronomers at the University of Hawaiʻi at Mānoa Institute for Astronomy and their collaborators have developed a technique that allows them to map collisions of giant galaxy clusters in three dimensions.

“Being unable to see these large-scale structures from different angles makes it very difficult to figure out their three-dimensional shapes, let alone their relative motions and interactions,” explains Harald Ebeling, IfA astronomer and an expert on galaxy clusters. “All we see in our images is a 2-D projection of a 3-D structure onto the plane of the sky.”

Creating 3-D reconstructions of merging galaxy clusters

Luckily, when two galaxy clusters collide, astronomers can make use of a clever combination of observations to make the invisible visible. In three recent studies, Ebeling and an international team of collaborators created 3-D models of merging galaxy clusters. Creating these models requires mapping all the components of a cluster—the galaxies that we see in visible light, the hot gas permeating the cluster that emits X-rays, and the invisible dark matter that can be detected only because its gravity distorts the images of objects behind the cluster.

To collect all these data, Ebeling’s team used three world-class observatories—the Mauna Kea Observatories (specifically, the Keck I telescope of the W.M. Keck Observatory and the Canada-France-Hawaiʻi Telescope), the Chandra X-ray Observatory and the Hubble Space Telescope.

The results of these 3-D reconstructions of some of the most massive structures in the universe will appear in three articles to be published by the Monthly Notices of the Royal Astronomical Society.

For more on the new 3-D technology, read the news release.

—Adapted from a UH Mānoa news release

Leave a Reply

Your email address will not be published. Required fields are marked *