The Astrophysical Journal · 1986 · 95 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsCosmologyExtragalactic AstronomyCosmic Microwave BackgroundCosmological ParametersExtragalactic Infrared AstronomyObservational CosmologyAnisotropy Of The Cosmic Microwave BackgroundCosmic Microwave Background AnisotropiesCosmic Microwave Background Parameter EstimationCosmological Parameter EstimationDipole Moment DeterminationFar-infrared Astronomy Of GalaxiesLinear Perturbation TheoryLuminosity Function Of Galaxies
IRAS 60 micron sources are used to map the local 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 + or - 9 and b = 40 + or - 8, 26 deg + or - 10 deg 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 of 0.85 + or - 0.16 (statistical IRAS error only), with nonlinear effects increasing the parameter by 0.15 percent. These values are in apparent disagreement with the values of 0.1-0.2 deduced from the Virgocentric infall and the cosmic virial theorem.