Third Galaxy Without Dark Matter Identified by Astronomers

Astronomers led by Yale have identified DF9 as the third galaxy known to apparently lack dark matter, utilizing data from the W.M. Keck Observatory and the Hubble Space Telescope. This discovery, detailed in The Astrophysical Journal, supports the hypothesis that these rare galaxies form through violent galactic collisions that remove their dark matter halos. The finding provides important evidence for a specific and unusual galaxy formation mechanism.