Measurement of CIB power spectra over large sky areas from Planck HFI maps

TL;DR

This paper measures the cosmic infrared background (CIB) power spectra over large sky areas using Planck HFI data, providing new insights into CIB anisotropies and their consistency with previous measurements.

Contribution

The study presents the first large-area CIB power spectra measurements from Planck HFI data, extending previous smaller-area analyses and confirming the power-law behavior of the CIB at high multipoles.

Findings

CIB power spectra are stable over 20,000 sq. degrees.

Spectra agree with Herschel measurements at high frequencies.

CIB fluctuations dominate at multipoles l > 300.

Abstract

We present new measurements of the power spectra of the cosmic infrared background (CIB) anisotropies using the Planck 2015 full-mission HFI data at 353, 545, and 857 GHz over 20000 square degrees. We use techniques similar to those applied for the cosmological analysis of Planck, subtracting dust emission at the power spectrum level. Our analysis gives stable solutions for the CIB power spectra with increasing sky coverage up to about 50% of the sky. These spectra agree well with Hi cleaned spectra from Planck measured on much smaller areas of sky with low Galactic dust emission. At 545 and 857 GHz our CIB spectra agree well with those measured from Herschel data. We find that the CIB spectra at l > 500 are well fitted by a power-law model for the clustered CIB, with a shallow index {\gamma}^cib = 0.53\pm0.02. This is consistent with the CIB results at 217 GHz from the cosmological parameter analysis of Planck. We show that a linear combination of the 545 and 857 GHz Planck maps is dominated by CIB fluctuations at multipoles l > 300.