Small temperature anisotropies in the cosmic microwave background can be sourcedby density perturbations via the late-time integrated Sachs-Wolfe effect. Large voidsand superclusters are excellent environments to make a localized measurement of thistiny imprint. In some cases excess signals have been reported. We probed these claimswith an independent data set, using the first year data of the Dark Energy Survey in adifferent footprint, and using a different super-structure finding strategy. We identified52 large voids and 102 superclusters at redshifts 0.2 < z < 0.65. We used the Jubileesimulation to a priori evaluate the optimal ISW measurement configuration for ourcompensated top-hat filtering technique, and then performed a stacking measurementof the CMB temperature field based on the DES data. For optimal configurations, wedetected a cumulative cold imprint of voids with ∆T_f ≈ −5.0 ± 3.7 µK and a hotimprint of superclusters ∆T_f ≈ 5.1 ± 3.2 µK ; this is ∼ 1.2σ higher than the expected|∆T_f | ≈ 0.6 µK imprint of such super-structures in ΛCDM. If we instead use an aposteriori selected filter size (R/Rv = 0.6), we can find a temperature decrement aslarge as ∆T_f ≈ −9.8 ± 4.7 µK for voids, which is ∼ 2σ above ΛCDM expectationsand is comparable to previous measurements made using SDSS super-structure data.
|Number of pages||14|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Early online date||17 Nov 2016|
|Publication status||Published - Mar 2017|