Probing the Mass Distribution with IRAS Galaxies

We present the results of three independent analyses in which we show that IRAS galaxies faithfully trace the underlying distribution the mass in the local universe. In the first analysis we compare the mass and the galaxy density fields and show that they are consistent within 60 $h^{-1}$Mpc. In the second one we show that the tidal velocity field of the Mark III catalog is consistent with the tidal velocity field predicted from the distribution of IRAS galaxies, hence indicating that IRAS galaxies trace the mass distribution well beyond 60 $h^{-1}$Mpc. Finally, a third analysis aimed at determining the mean biasing relation of IRAS galaxies showed no appreciable deviations from the linear biasing prescription.