Galaxy clusters

Definition

Galaxy clusters are large groups of galaxies bound together by gravity, typically containing hundreds to thousands of member galaxies. They represent the largest gravitationally bound structures in the universe and provide crucial insights into cosmic evolution and distribution.

5 Must Know Facts For Your Next Test

1. Galaxy clusters contain dark matter, hot gas, and multiple galaxies.
2. They are often found at the intersections of cosmic filaments in the large-scale structure of the universe.
3. The intracluster medium (ICM) is a hot, tenuous plasma that fills the space between galaxies within a cluster.
4. Gravitational lensing by galaxy clusters can magnify and distort the images of background objects.
5. Observations of galaxy clusters have provided strong evidence for the existence and properties of dark matter.

Review Questions

• What components make up a galaxy cluster?
• How do galaxy clusters contribute to our understanding of dark matter?
• What role does gravitational lensing play in studying galaxy clusters?

Related terms

Galaxy: A massive system consisting of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity.

Dark Matter: A form of matter that does not emit light or energy, detectable through its gravitational effects on visible objects.

Gravitational Lensing: The bending of light from a distant source around a massive object between the source and observer, often used to study mass distribution in galaxy clusters.