Dark matter becomes more mysterious

Astronomy : A new study has found that dark matter in dwarf galaxies is distributed smoothly rather than being densely clumped at their centers as the standard cosmological model had predicted. Dwarf galaxies are believed to be about 99% dark matter. Matt Walker from the Harvard–Smithsonian Center for Astrophysics and Jorge Penarrubia from the University of Cambridge determined the positions and velocities of thousands of stars in two Milky Way neighbors, the Fornax and Sculptor dwarf galaxies. From their measurements, the researchers inferred the dwarf galaxies’ dark matter distributions and concluded that either normal matter affects dark matter more than scientists thought, or dark matter isn’t as cold and slow-moving as previously predicted. Their findings will be published in an upcoming issue of the Astrophysical Journal.