Astronomers using a large group of space and ground observatories have discovered the most distant galaxy cluster yet. The galaxy cluster – called CL J1001+0220 (CL J1001 for short) – is located about 11.1 billion light-years from Earth.
Galaxy clusters are structures formed by groups of galaxies held together by their mutual gravity. Galaxy clusters can consist of hundreds to thousands of galaxies. They are the largest structures in the universe bound by gravity.
Tao Wang of the French Alternative Energies and Atomic Energy Commission (CEA) led the study, which was published in the Astrophysical Journal on August 30, 2016. Wang said in a statement:
This galaxy cluster isn’t just remarkable for its distance, it’s also going through an amazing growth spurt unlike any we’ve ever seen.
The core of CL J1001 contains 11 massive galaxies. Nine of the galaxies are experiencing an impressive “baby boom” of stars, according to a NASA statement.
Specifically, stars are forming in the cluster’s core at a rate that is equivalent to over 3,000 suns forming per year, a remarkably high value for a galaxy cluster, including those that are almost as distant, and therefore as young, as CL J1001.
Astronomers say this galaxy cluster might have been caught right after birth, a brief, but important stage of evolution never seen before. David Elbaz from CEA is a study co-author. He said:
It appears that we have captured this galaxy cluster at a critical stage just as it has shifted from a loose collection of galaxies into a young, but fully formed galaxy cluster.
Before the discovery of CL J1001, only loose collections of galaxies, known as protoclusters, had been seen at greater distances. The researchers say the CL J1001’s discovery pushes back the formation time of galaxy clusters by about 700 million years.
Alexis Finoguenov of the University of Helsinki in Finland is a study co-author. Finoguenov said:
We think we’re going to learn a lot about the formation of clusters and the galaxies they contain by studying this object, and we’re going to be searching hard for other examples.
The result is based on data from a large group of observatories in space and on the ground including Chandra, NASA’s Hubble Space Telescope and Spitzer Space Telescope, ESA’s XMM-Newton and Herschel Space Observatory, the NSF’s Karl G. Jansky Very Large Array, the Atacama Large Millimeter/submillimeter Array (ALMA) , the Institut de Radioastronomie Millimetrique Northern Extended Millimeter Array (IRAM NOEMA), and ESO’s Very Large Telescope.
Bottom line: A new record for the most distant galaxy cluster has been set. Astronomers say the cluster – called CL J1001 – is 11.1 billion light years from Earth and might have been caught right after birth.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.