Dipole anisotropies of the IRAS galaxies and the microwave background radiation

IRAS 60 μm sources are used to map the local (< or approx. =200 h-1 Mpc) gravitational field, and to determine its dipole component, on the assumption that the infrared radiation traces the matter. The dipole moment is found to point in the direction l = 248 +- 9 and b = 40 +- 8, 260 +- 100 away from the direction of the velocity of the Local Group relative to the microwave background radiation (statistical sampling errors only). Comparison of the two anisotropies, using the luminosity function of the IRAS galaxies and linear perturbation theory, yields an estimate of the cosmological density parameter, Ω0 = 0.85 +- 0.16 (statistical IRAS error only), with nonlinear effects increasing Ω0 by approx.0.15%. These values are in apparent disagreement with the values Ω0 = 0.1--0.2 deduced from the Virgocentric infall and the cosmic virial theorem