view Abstract Citations (16) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Bulk Flows, Shear, and the Great Attractor Kaiser, Nick Abstract The large inferred distance to the great attractor may indicate the need for more large-scale power than is provided by the "standard" cold dark matter model. In an attempt to quantify this I consider some statistics which measure the ratio of the bulk flow speed to the velocity shear averaged over a sample of galaxies. These should correspond approximately to the distance derived in fitting a "great attractor" model, and their probability distributions can be calculated given a theoretical fluctuation power spectrum providing tests for the shape of the power spectrum independent of the uncertain empirical normalization. These statistics are extracted from the elliptical galaxy sample of Dressler et al. and are compared with the predictions for various theoretical power spectra. In all models the distances have a broad distribution. I find no evidence for an excess of large-scale power relative to the cold dark matter predictions; there is, if anything, a suggestion of less large-scale power, though at a low level of significance. Peebles' isocurvature baryon fares less well; here ~ 90% of observers would see a shear to flow ratio less than that observed. If there is a conflict between these observations and the cold dark matter predictions it lies not in the shape of the power spectrum but in the fairly large normalization required. This may prove to be in conflict with the relative velocities of galaxies at small separations, but for the moment this remains an open question. Publication: The Astrophysical Journal Pub Date: January 1991 DOI: 10.1086/169572 Bibcode: 1991ApJ...366..388K Keywords: Computational Astrophysics; Dark Matter; Elliptical Galaxies; Galactic Evolution; Strange Attractors; Astronomical Models; Power Spectra; Taylor Series; Astrophysics; DARK MATTER; GALAXIES: CLUSTERING; GALAXIES: REDSHIFTS full text sources ADS |