Mapping the Integrated Sachs-Wolfe Effect

Abstract

On large scales, the anisotropies in the cosmic microwave background (CMB) reflect not only the primordial field but also the energy gain when photons traverse decaying gravitational potentials of large scales structure, the Integrated Sachs-Wolfe (ISW) effect. Decomposing the anisotropy signal into a primordial piece and an ISW component is more urgent than ever as cosmologists strive to understand the Universe on the largest of scales. Here we present a likelihood technique for extracting the ISW signal from measurements of the CMB, the distribution of galaxies, and maps of gravitational lensing. We test this technique first to simulated data and then we apply it to the combination of temperature anisotropies, the lensing map made by the Planck satellite, and the NVSS galaxy survey. We also show projections for upcoming surveys.