Astronomers on Maunakea Detect Oldest Known Galaxy Cluster
An international team of astronomers has discovered the oldest known protocluster.
A protocluster is a “dense system of dozens of galaxies in the early universe, growing a cluster,” according to a press release from the W.M. Keck Observatory.
The press release announced on Friday that the researchers discovered a collection of 12 galaxies in the Cetus constellation using the Subaru Telescope, as well as the Keck and Gemini observatories on Maunakea.
The researchers claim that the cluster, which they named “z66OD,” existed about 13 billion years ago, making it the earliest known protocluster.
Prior to the discovery, the SDF protocluster held the record for the oldest discovered cluster.
The SDF, which was also discovered by the Subaru Telescope, is about 100 million years younger than the z66OD.
“A protocluster is a rare and special system with an extremely high density, and not easy to find,” lead astronomer Yuichi Harikane said in the release.
Scientists say the new discovery suggests that protoclusters already existed when the universe was only about 800 million years old.
While galaxy clusters can contain thousands of members, astronomers are still unsure of how these masses form.