Large Scale Traces of Solar System Cold Dust on CMB Anisotropies

TL;DR

This paper investigates how cold dust in the outer Solar System could produce microwave anisotropies affecting CMB measurements, potentially explaining some observed anomalies and impacting cosmological parameter estimates.

Contribution

It introduces a simple toy model for Solar System dust emission, constrains its amplitude with COBE data, and analyzes its effects on CMB anomalies and cosmological parameters.

Findings

The dust emission model reduces CMB anomalies like low quadrupole and ecliptic plane excess.

The foreground impacts estimates of primordial density perturbation parameters.

Constraints from COBE data are compatible with the model's amplitude.

Abstract

We explore the microwave anisotropies at large angular scales produced by the emission from cold and large dust grains, expected to exist in the outer parts of the Solar System, using a simple toy model for this diuse emission. Its amplitude is constrained in the Far-IR by the COBE data and is compatible with simulations found in the literature. We analyze the templates derived after subtracting our model from the WMAP ILC 7 yr maps and investigate on the cosmological implications of such a possible foreground. The anomalies related to the low quadrupole of the angular power spectrum, the two-point correlation function, the parity and the excess of signal found in the ecliptic plane are significantly alleviated. An impact of this foreground for some cosmological parameters characterizing the spectrum of primordial density perturbations, relevant for on-going and future CMB anisotropy experiments, is found.