Optimal bolometer transfer function deconvolution for CMB experiments through maximum likelihood mapmaking

• DOI: 10.48550/arxiv.2405.07729
• Publication Date: 2024-05-13
• Authors: A. Basyrov; Nils-Ole Stutzer; J. G. S. Lunde; H. K. Eriksen; E. Gjerløw; Duncan J. Watts; I. K. Wehus
• Keywords: Optical transfer function

We revisit the impact of finite time responses bolometric detectors used for deep observations cosmic microwave background (CMB). Until now, bolometer transfer functions have been accounted through a two-step procedure by first deconvolving an estimate their Fourier-space representation from raw time-ordered data (TOD), and then averaging deconvolved TOD into pixelized maps. However, many experiments, including Planck High Frequency Instrument (HFI), it is necessary to apply additional low-pass filter avoid excessive noise boost, which leads asymmetric effective beam. In this paper we demonstrate that effect can be avoided if function deconvolution pixelization operations are performed simultaneously integrated maximum likelihood mapmaking. The resulting algorithm structurally identical artDeco introduced Keih\"anen & Reinecke (2012) beam deconvolution. illustrate relevance method with simulated HFI 143 GHz data, find both more symmetric than procedure, in sky-averaged ellipticity 64 % lower, full-width-at-half-maximum (FWHM) 2.3 smaller. Similar improvements expected any other bolometer-based CMB experiments long constants.