Astronomers Discover Third Galaxy Without Dark Matter
a day ago
- #Astrophysics
- #Dark Matter
- #Galaxy Formation
- Astronomers discovered DF9, the third known galaxy lacking dark matter, using W. M. Keck Observatory on Maunakea, Hawai'i.
- DF9 is part of a linear structure with two other dark matter-deficient galaxies (DF2 and DF4), suggesting they formed together from a violent galactic collision.
- The findings provide evidence that ordinary matter can separate from dark matter during high-speed collisions, supporting dark matter as a physical substance.
- Observations with Keck Cosmic Web Imager (KCWI) showed DF9's mass matches only visible matter, with no significant dark matter content.
- Future studies will search for leftover gas from the collision and analyze galaxy gas content to further understand galaxy formation processes.