Unknown and invisible dark matter has been identified by the Webb Telescope within the collision of a galaxy cluster.
In a groundbreaking discovery, a team of astronomers led by PhD student Sangjun Cha of Yonsei University has used the James Webb Space Telescope (JWST) to weigh and map the mass of the iconic Bullet Cluster more accurately than ever before. The Bullet Cluster, a massive structure formed from the merging of two galaxy clusters 3.8 billion light-years away, has been the subject of intense scientific interest due to its unique properties.
The JWST's near-infrared vision has provided the most detailed and precise maps of dark matter in this galaxy cluster collision to date. Dark matter, a mysterious substance that doesn't emit or reflect light and makes up most of the Universe's mass, has been located within the Bullet Cluster.
Key findings include the precise mapping of dark matter using gravitational lensing, where the gravity of the cluster bends light from distant background galaxies. This allowed astronomers to capture extremely faint and distant galaxies, contributing to a vast dataset to measure the cluster's mass distribution from its core to outskirts.
The Bullet Cluster consists of two massive colliding galaxy clusters with galaxies and hot gas visible in different wavelengths. Webb captured the galaxies and foreground stars in near-infrared, while Chandra X-ray Observatory showed the hot gas (pink), and dark matter is depicted in blue based on lensing maps.
One of the most significant discoveries is that dark matter aligns closely with galaxies and does not behave like the hot gas. This confirms that dark matter does not interact strongly with itself or normal matter through forces other than gravity. The hot gas was slowed and left behind during the collision, but dark matter and galaxies remained coincident and moved together, supporting the idea that dark matter is collisionless.
Researchers also confirmed that intracluster light—stars not bound to any single galaxy but the cluster—can serve as a reliable tracer of dark matter. This is significant because intracluster stars follow the dark matter distribution even in this highly dynamic merging system.
JWST's refined mass measurements reveal asymmetric and elongated mass regions, indicating complex past mergers, adding detail to understanding the cluster's structure and evolution. However, the team's study is only part of the story, and future observations, such as those from the Nancy Grace Roman Space Telescope, will be needed for precise measurements of the entire Bullet Cluster.
With data from the Nancy Grace Roman Space Telescope, scheduled to launch by May 2027, researchers will be able to recreate the actual collision of the galaxy clusters on computers, providing a more comprehensive understanding of the Bullet Cluster's formation and evolution.
The team's study also reveals that dark matter is eerily quiet, with no detectable interactions. The image reveals an asymmetric, elongated area of mass along the left edge of the blue region, which is a clue pointing to previous mergers in the galaxy cluster on the left. This dark matter map suggests the Bullet Cluster may have gone through more than one dramatic collision, with a mass clump on the left potentially being the fingerprint of an earlier or later collision.
In summary, the JWST has enhanced mapping of the Bullet Cluster's dark matter, confirming its collisionless nature and providing finer details of its distribution relative to galaxies and gas. This deepens insight into dark matter’s role in structure formation and cosmic collisions.
- The groundbreaking study, led by Sangjun Cha of Yonsei University, has utilized the James Webb Space Telescope (JWST) for astrophotography, offering the most detailed and precise maps of dark matter in the Bullet Cluster.
- The Bullet Cluster, a fascinating structure formed from the merging of two galaxy clusters, has been a subject of intense interest due to its unique properties in the realm of space and astronomy.
- The team's work has significant implications for environmental science, as they confirmed that intracluster light—stars not bound to any single galaxy but the cluster—can serve as a reliable tracer of dark matter.
- The health-and-wellness and mental-health sectors may also benefit from this research, as understanding dark matter's role in structure formation and cosmic collisions can potentially lead to new scientific breakthroughs.
- To further enrich our understanding of the Bullet Cluster's evolution, researchers are eagerly awaiting data from the future Nancy Grace Roman Space Telescope, which will provide a more comprehensive understanding of the Bullet Cluster's formation through computer simulations.
- This study underscores the importance of continued investment in environmental-science, space-and-astronomy, and telescope technology, as they pave the way for a better comprehension of the universe and its mysterious components like dark matter.