August 22, 2013
A team of astronomers has discovered the most distant cluster of red galaxies ever observed using FourStar, a new and powerful near-infrared camera on the 6.5m Magellan Baade Telescope. The galaxy cluster is located 10.5 billion light years away in the direction of the constellation Leo. It is made up of 30 galaxies packed closely together, forming the earliest known “galaxy city” in the universe.
The 3-D map revealed the conspicuous concentration of galaxies that existed when the universe was only three billion years old. “This means the galaxy cluster is still young and should continue to grow into an extremely dense structure possibly containing thousands of galaxies,” explained lead author Lee Spitler of Australia’s Swinburne University of Technology.
Studying this system will help astronomers understand how galaxies are influenced by their environment, evolve, and assemble into larger structures.
Remarkably, the cluster was completely missed by previous surveys, which searched this region of the sky for thousands of hours and were conducted by all the major ground- and space-based observing facilities, including the Hubble Space Telescope. Despite these intense observations, accurate distances for such faint and distant galaxies were missing until the advent of FourStar.