Large Angular-scale Multipoles at Redshift ∼ 0.8

Abstract

Abstract We prepare the full sky radio galaxy map ( ), using the north NRAO VLA Sky Survey and south Sydney University Molonglo Sky Survey galaxy catalogs, and study the large-scale multipole anomalies. These galaxies are roughly at redshift z ∼ 0.8 and are therefore tracing the matter distribution at very large scales. The quadruple and octopole from the radio galaxy catalog are consistent with ΛCDM for a reasonable value of galaxy bias and we do not find dipole–quadruple–octopole alignment as seen in cosmic microwave background (CMB) temperature maps. The quadrupole direction is roughly 46° away from dipole, and the octopole direction is approximately 33° from dipole. The angle between quadrupole and octopole is around 70°. We have large errors in multipole directions due to shot noise. However, with the data that is currently available we do not find any significant alignment between the l = 1, 2, 3 modes. The magnitude of all multipoles, except dipole, are roughly consistent with ΛCDM for reasonable galaxy bias. The dipole magnitude remains inconsistent with CMB as reported in previous studies. Our findings may impose stringent constraints on cosmological models with large-scale anisotropy features.