SRo112: an improved mapmaking approach to reduce large-scale systematic effects in the Planck High Frequency Instrument legacy maps
|Author(s)||Delouis Jean Marc1, 2, 3, Pagano L.2, 4, 5, 6, 7, Mottet S.2, 3, Puget J-L2, 6, 7, Vibert L.2, 6|
|Affiliation(s)||1 : Univ Brest, IFREMER, CNRS, LOPS,IRD, Brest, France.
2 : CNRS UMR7095, Inst Astrophys Paris, 98 Bis Blvd Arago, F-75014 Paris, France.
3 : Sorbonne Univ, UMR7095, 98 Bis Blvd Arago, F-75014 Paris, France.
4 : Univ Ferrara, Dipartimento Fis & Sci Terra, Via Saragat 1, I-44100 Ferrara, Italy.
5 : Ist Nazl Fis Nucl, Sez Ferrara, Via Saragat 1, I-44100 Ferrara, Italy.
6 : Univ Paris Saclay, Univ Paris Sud, CNRS, Inst Astrophys Spatiale, Bat 121, F-91405 Orsay, France.
7 : Univ PSL, Sorbonne Univ, CNRS, Ecole Normale Super,LERMA,Observ Paris, Paris, France.
|Source||Astronomy & Astrophysics (1432-0746) (Edp Sciences S A), 2019-09 , Vol. 629 , N. A38 , P. 19p.|
|WOS© Times Cited||12|
|Keyword(s)||cosmology: observations, cosmic background radiation, surveys, methods: data analysis|
This paper describes an improved map making approach with respect to the one used for the Planck High Frequency Instrument 2018 Legacy release. The algorithm SRo112 better corrects the known instrumental effects that still affected mostly the polarized large-angular-scale data by distorting the signal, and/or leaving residuals observable in null tests. The main systematic effect is the nonlinear response of the onboard analog-to-digital convertors that was cleaned in the Planck HFI Legacy release as an empirical time-varying linear detector chain response which is the first-order effect. The SRo112 method fits the model parameters for higher-order effects and corrects the full distortion of the signal. The model parameters are fitted using the redundancies in the data by iteratively comparing the data and a model. The polarization efficiency uncertainties and associated errors have also been corrected based on the redundancies in the data and their residual levels characterized with simulations. This paper demonstrates the effectiveness of the method using end-to-end simulations, and provides a measure of the systematic effect residuals that now fall well below the detector noise level. Finally, this paper describes and characterizes the resulting SRo112 frequency maps using the associated simulations that are released to the community.