image: This is Galaxy cluster Abell 2744 with dark matter map. This material relates to a paper that appeared in the March 27, 2015 issue of Science, published by AAAS. The paper, by David Harvey at the École Polytechnique Fédérale de Lausanne in Versoix, Switzerland, and colleagues was titled, "The nongravitational interactions of dark matter in colliding galaxy clusters." view more
Credit: [Credit: NASA, ESA, D. Harvey (École Polytechnique Fédérale de Lausanne, Switzerland), R. Massey (Durham University, UK), ESO and D. Coe (STScI), J. Merten (Heidelberg/Bologna)]