THE MASS-DISTRIBUTION IN THE NEARBY UNIVERSE

We present a new reconstruction of the mass density and the peculiar v elocity fields in the nearby universe using recent measurements of Tul ly-Fisher distances for a sample of late spirals. We find significant differences between our reconstructed fields and those obtained in ear lier work: overdensities tend to be more compact while underdense regi ons, consisting of individual voids, are more abundant, Our results su ggest that voids observed in redshift surveys of galaxies represent re al voids in the underlying matter distribution. While we detect a bulk velocity of similar to 300 km s(-1), within a top-hat window 6000 km s(-1) in radius, the flow is less coherent than previously claimed, ex hibiting a bifurcation toward the Perseus-Pisces and the Great Attract or complexes. This is the first time that this feature is seen from pe culiar velocity measurements. The observed velocity field resembles, m ore closely than any previous reconstruction, the velocity field predi cted from self-consistent reconstructions based on all-sky redshift su rveys. This better match is likely to affect estimates of the paramete r beta = Omega(0.6)/b and its uncertainty based on velocity-velocity c omparisons.