Mystery deepens around dark core in cosmic collision
Friday, March 2, 2012 - 11:01
in Astronomy & Space
Five years ago, San Francisco State researcher Andisheh Mahdavi and his colleagues observed an unexpected dark core at the center of Abell 520, a cosmic "train wreck" of galaxy clusters. With new space-based telescope observations, they have confirmed that the core really does exist. But they are no closer to explaining why it is there.