Star formation

Star-rich early galaxy clusters

Journal name:
Date published:
Published online

Galaxy clusters in the early Universe produced more stars than their more modern counterparts.

When a galaxy becomes part of a cluster — a group of galaxies bound together by gravity — its crowded surroundings often cause it to stop producing stars, an effect called environmental quenching. Using the Keck Observatory in Hawaii and the Very Large Telescope in Chile, a team led by Julie Nantais at the Andres Bello University in Santiago observed four galaxy clusters nearly 10 billion years old. They found that, in these early clusters, only about 30% more of the galaxies had stopped producing stars than had the surrounding galaxies, compared with a difference of about 50% in newer clusters.

Knowing how quenching changes over the history of the Universe may help scientists to determine why the cluster environment causes the phenomenon.

Astron. Astrophys. 592, A161 (2016)

Additional data