The actual Rees--Sciama effect from the Local Universe

TL;DR

This study investigates whether the Rees-Sciama effect from local superclusters can explain the CMB quadrupole-octopole alignment, finding it insufficient in amplitude but providing an upper limit estimate from observational data.

Contribution

The paper models the local Rees-Sciama effect using constrained hydrodynamical simulations and assesses its impact on CMB anisotropies, offering new insights into secondary anisotropies.

Findings

Rees-Sciama effect peaks at low multipoles with amplitudes up to 6.6 μK.

The effect's quadrupole aligns with observations but is too weak to explain the alignment.

An upper limit of 30 μK for the RS effect amplitude is derived from WMAP-3 data.

Abstract

Observations of the Cosmic Microwave Background (CMB) have revealed an unexpected quadrupole-octopole alignment along a preferred axis pointing toward the Virgo cluster. We here investigate whether this feature can be explained in the framework of the concordance model by secondary anisotropies produced by the non-linear evolution of the gravitational potential, the so-called Rees-Sciama (RS) effect. We focus on the effect caused by the local superclusters, which we calculate using a constrained high-resolution hydrodynamical simulation, based on the IRAS 1.2-Jy all-sky galaxy redshift survey, which reproduces the main structures of our Universe out to a distance of 110 Mpc from our Galaxy. The resulting RS effect peaks at low multipoles and has a minimum/maximum amplitude of -6.6\mu K 1.9\mu K. Even though its quadrupole is well aligned with the one measured for the CMB, its amplitude is not sufficient to explain the observed magnitude of the quadrupole/octopole alignment. In addition, we analyze the WMAP-3 data with a linear matched filter in an attempt to determine an upper limit for the RS signal amplitude on large scales. We found that it is possible to infer a weak upper limit of 30\mu K for its maximum amplitude.