POTENTIAL, VELOCITY, AND DENSITY FIELDS FROM REDSHIFT-DISTANCE SAMPLES - APPLICATION - COSMOGRAPHY WITHIN 6000 KILOMETERS PER-SECOND

We present the first results of applying a potential flow reconstruction algorithm to the real universe. The method, described in detail in the preceding paper, takes as input radial peculiar velocities and distances for a set of objects that trace large-scale motions. Our sample is based on 544 early-type galaxies with Dn - σ distance estimates and 429 spirals with infrared Tully-Fisher distances. From these data, the method reconstructs the three-dimensional potential, velocity, and mass density fields smoothed on large scales. The results are shown as maps of these fields, revealing the three-dimensional structure within 6000 km s-1 distance from the Local Group. For each map we provide an error map based on Monte Carlo simulations. The dominant recovered structure is an extended, deep potential well in the Hydra-Centaurus region, stretching across the Galactic plane toward Pavo, broadly confirming the "great attractor" (GA) model of Lynden-Bell et al. (1988). The peak density contrast in this region is given by Ω4/7δρ/ρ = 1.2 ± 0.4 with a Gaussian smoothing window of radius ≈ 1400 km s-1. The Local Supercluster appears to be an extended ridge on the near flank of the GA, proceeding through the Virgo Southern Extension to the Virgo and Ursa Major clusters. The Virgo cluster and the Local Group are both falling toward the bottom of the GA potential well, with peculiar velocities (smoothed on a scale of 500 km s-1) of 658 ± 121 km s-1 and 565 ± 125 km s-1, respectively. Several large regions of below-average mass density are discovered that match known voids in the galaxy distribution. A general correlation exists between the mass and galaxy distributions, except for a significant disagreement in the Perseus-Pisces supercluster, which is practically invisible in the reconstructed mass distribution. However, the very sparse sampling of measured distances in the current sample may cause us to underestimate the amplitude of both positive and negative density perturbations in that direction. The average velocities in spheres of radii 4000 and 6000 km s-1 centered on the Local Group (with prior, additional smoothing by a Gaussian of radius 1200 km s-1) are 388 ± 67 km s-1 toward L = 177°, B = -15°, and 327 ± 82 km s-1 toward L = 194°, B = 5°, respectively, compared with predicted rms velocities of 287 and 224 km s-1 for the unbiased cold dark matter model.