They found threads of dark matter
…spinning between clusters of galaxies. That’s how the Christian Science Monitor describes the remarkable discovery of the scaffolding that holds together the universe:
Three-dimensional astronomical maps developed since the late 1980s show that the vast majority of the universe’s galaxies are distributed as threads and sheets that span the universe, with galaxy clusters as well as superclusters of thousands of galaxies appearing where threads and sheets intersect. These structures were thought to have formed on a framework of dark matter, the unseen form of matter that scientists believe binds galaxies together.
The results announced Thursday mark “the first time we have observationally verified this very important theoretical prediction” of a dark-matter backbone, says Jörg Dietrich, an astronomer at the University of Munich Observatory in Germany who led the team.
Dr. Dietrich’s team studied a thread that connects two galaxy clusters, Abel 222 and 223, some 2.4 billion light-years away. X-ray emissions observed by the XMM-Newton X-ray observatory showed that the clusters appeared to be linked by an expanse of hot gas. Additional observations indicated that the clusters were too far apart for their surrounding clouds of hot gas to overlap, suggesting that something else had to be at work.
Further observations at visible wavelengths with Japan’s Subaru telescope atop Mauna Kea in Hawaii showed that gravity from something more massive than the individual galaxies between the clusters was bending light and magnifying objects behind it. This phenomenon is known as gravitational lensing and left dark matter as the last explanation standing.
The team estimates the filament’s mass at between 65 trillion and 98 trillion times the mass of the sun, with the gas making up about 9 percent of the mass.
So they’ve finally (just about) seen some dark matter.
[via Mr. Goodstein]