Planck early results. VI. The High Frequency Instrument data processing

TL;DR

This paper details the processing of Planck-HFI data to produce high-quality temperature maps of the sky at multiple frequencies, achieving high sensitivity, resolution, and photometric accuracy for cosmological analysis.

Contribution

It presents a comprehensive data processing pipeline that delivers accurate, high-resolution sky maps from raw Planck-HFI data, meeting the project's scientific goals.

Findings

Maps achieve angular resolutions from 4.4' to 9.9'

White noise level around 1.5 μK·deg in main CMB channels

Photometric accuracy better than 2% at 100-353 GHz

Abstract

We describe the processing of the 336 billion raw data samples from the High Frequency Instrument (HFI) which we performed to produce six temperature maps from the first 295 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545 and 857 GHz with an angular resolution ranging from 9.9 to 4.4^2. The white noise level is around 1.5 {\mu}K degree or less in the 3 main CMB channels (100--217GHz). The photometric accuracy is better than 2% at frequencies between 100 and 353 GHz and around 7% at the two highest frequencies. The maps created by the HFI Data Processing Centre reach our goals in terms of sensitivity, resolution, and photometric accuracy. They are already sufficiently accurate and well-characterised to allow scientific analyses which are presented in an accompanying series of early papers. At this stage, HFI data appears to be of high quality and we expect that with further refinements of the data processing we should be able to achieve, or exceed, the science goals of the Planck project.