The European Space Agency’s (ESA) Euclid space telescope has discovered its first Einstein ring, a rare and stunning phenomenon that allows scientists to “weigh” dark matter at the heart of a galaxy almost 600 million light-years away. This discovery is significant as it provides valuable insights into the nature of dark matter and its role in shaping the universe.
The Euclid telescope spotted the Einstein ring, named “Altieri’s lens,” while observing the galaxy NGC 6505, located about 590 million light-years from Earth. The ring is a perfect circle formed by the gravitational lensing effect, where the massive galaxy acts as a cosmic lens to focus light from a distant galaxy.
By analyzing the Einstein ring, scientists were able to estimate that the dark matter at the center of NGC 6505 makes up only 11% of its mass. This finding provides a unique opportunity to study the properties of dark matter in a galaxy, which is crucial for understanding the evolution and formation of galaxies.
The Euclid telescope’s discovery has also shed light on the composition and structure of the galaxy’s central regions, where stars and dark matter dominate. The team was able to measure the proportion of low-mass stars to high-mass stars, known as the initial mass function.
This breakthrough is a significant milestone in the Euclid mission, which aims to create the most precise 3D map ever made of the universe. By studying the distribution of matter, both visible and dark, in galaxies and galaxy clusters, scientists hope to gain insights into the nature and evolution of the universe over time.
Source: https://www.space.com/euclid-einstein-ring-dark-matter