The integrated Sachs-Wolfe (ISW) effect measures the decay of the gravitational potential due to cosmic acceleration and is thus a direct probe of dark energy. In some of the earlier studies, the amplitude of the ISW effect was found to be in tension with the predictions of the standard Lambda cold dark matter (ΛCDM) model. We measure the cross power of galaxies and active galactic nuclei (AGN) from the Wide-field Infrared Survey Explorer mission with cosmic microwave background temperature data from WMAP9 in order to provide an independent measurement of the ISW amplitude. Cross-correlations with the recently released Planck lensing potential maps are used to calibrate the bias and contamination fraction of the sources, thus avoiding systematic effects that could be present when using autospectra to measure bias. We find an amplitude of the cross power of A=1.24±0.47 from the galaxies and A=0.88±0.74 from the AGN, fully consistent with the ΛCDM prediction of A=1. The ISW measurement signal-to-noise ratio is 2.7 and 1.2 respectively. Comparing the amplitudes of the Galaxy and AGN cross-correlations, which arise from different redshifts, we find no evidence for redshift evolution in dark energy properties, consistent with a cosmological constant.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Apr 24 2015|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)