Planck 2013 results. XIV. Zodiacal emission

TL;DR

This paper analyzes Planck satellite data to characterize zodiacal emission across the sky at millimetre wavelengths, improving models of interplanetary dust and assessing contamination in cosmic microwave background measurements.

Contribution

It provides new measurements of zodiacal dust emissivities at multiple wavelengths and refines the COBE zodiacal model using Planck data, aiding in accurate CMB analysis.

Findings

Emissivity of diffuse cloud decreases with wavelength.

Dust band properties differ from diffuse cloud.

Zodiacal correction to CMB maps is minimal.

Abstract

The Planck satellite provides a set of all-sky maps at nine frequencies from 30 GHz to 857 GHz. Planets, minor bodies, and diffuse interplanetary dust emission (IPD) are all observed. The IPD can be separated from Galactic and other emissions because Planck views a given point on the celestial sphere multiple times, through different columns of IPD. We use the Planck data to investigate the behaviour of zodiacal emission over the whole sky at sub-millimetre and millimetre wavelengths. We fit the Planck data to find the emissivities of the various components of the COBE zodiacal model -- a diffuse cloud, three asteroidal dust bands, a circumsolar ring, and an Earth-trailing feature. The emissivity of the diffuse cloud decreases with increasing wavelength, as expected from earlier analyses. The emissivities of the dust bands, however, decrease less rapidly, indicating that the properties of the grains in the bands are different from those in the diffuse cloud. We fit the small amount of Galactic emission seen through the telescope's far sidelobes, and place limits on possible contamination of the CMB results from both zodiacal and far-sidelobe emission. When necessary, the results are used in the Planck pipeline to make maps with zodiacal emission and far sidelobes removed. We show that the zodiacal correction to the CMB maps is small compared to the Planck CMB temperature power spectrum and give a list of flux densities for small Solar System bodies.