The ISW effect in the light of the Planck 2015 data

Abstract

We review the detection and characterization of the ISW effect in the light of the Planck 2015 data release. In particular, we establish a robust 4sigma detection through the joint cross-correlation of the Planck CMB data with different tracers of the large-scale structure (NVSS, WISE, SDSS and the Planck lensing map). We study which of the tracers contributes the most to the detection, showing that the Planck lensing provides a 3sigma, via the ISW-lensing bispectrum. This detection implaies a complementary evidence of the accelerated expansion of the universe, assuming that the flatness of its spatial geometry. Using the Planck polarization information, we produce specific CMB temperature maps, where the correlation with the E-mode is isolated. These maps are used to study further the ISW effect, in particular, by stacking the CMB fluctuations in the positions of known super-clusters and super-voids, which already served to highlight and anomalously large ISW signal. These maps do not show any clear evidence of biases on this signal caused by primary CMB fluctuations. Finally, we also provide reconstructions of the ISW fluctuations produced by different large-scale structure tracers.