Title:
Cosmic Flows on 100 Mpc/h Scales
Abstract:
We formulate a "Minimal Variance" (MV) optimization analysis
of the low moments of the cosmic velocity field. These MV estimates
can be designed to calculate the moments on a particular scale with
minimal sensitivity to small scale power and thus different surveys
can be compared. The MV moments have virtually no correlations between
them and so they are orthogonal. Our estimate of the bulk flow on
scales of 100 Mpc/h has a magnitude of 416+/-78 km/s towards the
Galactic l=282+/-11 degrees and b=10+/-6 degrees, in good agreement
with previous estimates and in a 99.5% CL disagreement with LCDM with
WMAP5 central paramenters. The higher moments (shear and octupole) are
consistent with the LCDM WMAP5 power spectrum. The relative low shear
signal suggest that the sources responsible for this flow must be at
large distances, >300 Mpc/h.