The Great Attractor: do galaxies trace the large-scale mass distribution?

Large-scale inhomogeneities have been discovered in the distribution of galaxies and attempts have been made to infer, from their motions, the distribution of the additional, invisible matter that dominates the dynamical evolution of the Universe. Like the galaxy distribution, the smoothed distribution of mass density shows high-contrast features stretching over vast regions. The local volume of the Universe seems to be dominated by a single region of above-average mass density: the Great Attractor. (author)