Planck 2015 results. XXI. The integrated Sachs-Wolfe effect
  This paper presents a study of the ISW effect from the Planck 2015
temperature and polarization data release. The CMB is cross-correlated with
different LSS tracers: the NVSS, SDSS and WISE catalogues, and the Planck 2015
lensing map. This cross-correlation yields a detection at $4\,\sigma$, where
most of the signal-to-noise is due to the Planck lensing and NVSS. In fact, the
ISW effect is detected only from the Planck data (through the ISW-lensing
bispectrum) at $\approx 3\,\sigma$, which is similar to the detection level
achieved by combining the cross-correlation signal coming from all the
catalogues. The ISW signal allow us to detect $\Omega_\Lambda$ at more than
$3\,\sigma$. This cross-correlation analysis is performed only with the Planck
temperature data, since the polarization scales available in the 2015 release
do not permit significant improvement of the CMB-LSS cross-correlation
detectability. Nevertheless, polarization data is used to study the anomalously
large ISW signal previously reported through the stacking of CMB features at
the locations of known superstructures. We find that the current Planck
polarization data do not exclude that this signal could be caused by the ISW
effect. In addition, the stacking of the Planck lensing map on the locations of
superstructures exhibits a positive cross-correlation with these large-scale
structures. Finally, we have improved our previous reconstruction of the ISW
temperature fluctuations by combining the information encoded in all the
previously mentioned LSS tracers. In particular, we construct a map of the ISW
secondary anisotropies and the corresponding uncertainties map, obtained from
simulations. We also explore the reconstruction of the ISW anisotropies caused
by the LSS traced by the 2MPZ survey by directly inverting the density field
into the gravitational potential field.
