Planck data show no signs of dark flow

New Scientist : An analysis of the cosmic microwave background (CMB) map produced by the European Space Agency’s Planck spacecraft has found no evidence of “dark flow"âmdash;a stream of galaxy clusters apparently rushing toward the same region of the universe. Dark flow was first suggested in 2008 by the CMB map produced by the Wilkinson Microwave Anisotropy Probe ( WMAP). The apparent structural favoritism ran contrary to the generally accepted model of cosmology, however, and attempts to explain it evoked exotic physics. Because not all of the analyses of the WMAP data saw the same dark flow effect, researchers hoped that the next CMB mapping would settle the question. The first analysis of Planck‘s more detailed data, which shows no evidence of that large-scale structural favoritism, appears to have done so. Nevertheless, one of the Planck researchers and the lead author of the original dark flow paper are both working on their own analyses of the new data.