The discovery of a ancient cluster of galaxies at the dawn of the cosmos, the most distant ever found at 13.0 billion light years away, suggests that a large structure already existed at a time when the universe was only about 800 million years old or 6 percent of its present age. Finding a cluster this far away makes finding the needle in the haystack seem an easy task, but more importantly, it reveals “the dark skeleton of the universe.”
“We do not know what dark matter is, but if it has anything to do with any scalar particles, it may be older than the Big Bang,” says astrophysicist Tommi Tenkanen at the Johns Hopkins University, who was not part of a new University of Tokyo study that proposes the axion as a candidate for dark matter.
The universe, perhaps surprisingly, is not comprised of galaxies randomly distributed throughout space; that is, it is not very homogeneous. Instead, its galaxies are clustered into distinct structures that harbor dark matter, typically gigantic filaments separated by vast voids—the “large-scale structure (LSS),” an architecture whose discovery and mappings were pioneered by Harvard-Smithsonian Center for Astrophysics astronomers about thirty years ago.
