NASA’s James Webb Space Telescope has captured highly detailed images of the Bullet Cluster, revealing a greater abundance of extremely faint and distant galaxies than ever before. The telescope’s observations have allowed researchers to map the contents of the colliding galaxy clusters with unprecedented precision.
The Bullet Cluster is comprised of two massive collections of galaxies bound by gravity, which act as gravitational lenses to magnify the light of background galaxies. By studying this phenomenon, scientists can infer the distribution of dark matter, a type of invisible matter that does not interact with itself or emit/reflect light.
Using Webb’s near-infrared observations, researchers measured thousands of galaxies in the cluster and accurately “weighed” both visible and invisible mass. They also mapped and measured the collective light emitted by stars no longer bound to individual galaxies, known as intracluster stars. These findings confirm that intracluster light can be a reliable tracer of dark matter.
The revised map of the Bullet Cluster shows refined measurements of dark matter, calculated using Webb’s observations. The team’s findings indicate that dark matter does not interact with itself and lines up with galaxies. This knowledge refines our understanding of how mass is spread throughout the galaxy cluster.
Future observations from NASA’s Nancy Grace Roman Space Telescope will allow researchers to create a complete map of the Bullet Cluster, enabling precise measurements of its entire mass. The James Webb Space Telescope continues to solve mysteries in our solar system and beyond, offering insights into distant worlds and the origins of our universe.
Source: https://science.nasa.gov/missions/webb