Dark Matter Dynamics: Exploring the Strange Milky Way Satellite, Crater 2

Crater 2, a large, dim satellite galaxy, exhibits properties that challenge traditional cold dark matter theories. The SIDM theory provides a better explanation, suggesting dark matter interactions that reduce density and increase galaxy size, matching observations.

Crater 2, located approximately 380,000 light years from Earth, is one of the largest satellite galaxies of the Milky Way. Extremely cold and with slow-moving stars, Crater 2 has low surface brightness. How this galaxy originated remains unclear.

Challenges in Understanding Crater 2
“Since its discovery in 2016, there have been many attempts to reproduce Crater 2’s unusual properties, but it has proved very challenging,” said Hai-Bo Yu, a professor of physics and astronomy at the University of California, Riverside, whose team now offers an explanation for Crater 2’s origin in a paper published recently in The Astrophysical Journal Letters.