Limits on three-point correlations in the COBE DMR first-year anisotropy maps

Abstract

We compute the three-point temperature correlation function of the COBE Differential Microwave Radiometer (DMR) first-year sky maps to search for non-Gaussian temperature fluctuations. The level of fluctuations seen in the computed correlation function are too large to be attributable solely to instrument noise. However the fluctuations are consistent with the level expected to result from a superposition of instrument noise and sky signal arising from a Gaussian power-law model of initial fluctuations, with a quadrupole normalized amplitude of 17 μK and a power-law spectral index n= 1. We place limits on the amplitude of intrinsic three-point correlations with a variety of predicted functional forms. Show more