The Integrated Sachs-Wolfe Signal from BOSS Super-Structures

TL;DR

This study constructs a linear ISW signal map from BOSS data, verifies its imprint on Planck CMB maps, and analyzes super-structures, revealing their properties and orientations, but finds limited correlation with the CMB.

Contribution

It introduces a new ISW template based on BOSS data, characterizes supervoids and superclusters in three dimensions, and explores their impact on CMB temperature fluctuations.

Findings

The ISW imprint is verified at 97% confidence level.

Supervoids are elongated along the line-of-sight.

No significant correlation found with the new super-structure catalogue.

Abstract

Cosmic structures leave an imprint on the microwave background radiation through the integrated Sachs-Wolfe effect. We construct a template map of the linear signal using the SDSS-III Baryon Acoustic Oscillation Survey at redshift 0.43 < z < 0.65. We verify the imprint of this map on the Planck CMB temperature map at the 97% confidence level and show consistency with the density-temperature cross-correlation measurement. Using this ISW reconstruction as a template we investigate the presence of ISW sources and further examine the properties of the Granett-Neyrinck-Szapudi supervoid and supercluster catalogue. We characterise the three-dimensional density profiles of these structures for the first time and demonstrate that they are significant structures. Model fits demonstrate that the supervoids are elongated along the line-of-sight and we suggest that this special orientation may be picked out by the void-finding algorithm in photometric redshift space. We measure the mean temperature profiles in Planck maps from public void and cluster catalogues. In an attempt to maximise the stacked ISW signal we construct a new catalogue of super-structures based upon local peaks and troughs of the gravitational potential. However, we do not find a significant correlation between these structures and the CMB temperature.