Full-sky beam convolution for cosmic microwave background applications

Adriaan J. Duivenvoorden, Jon E. Gudmundsson, Alexandra S. Rahlin

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


We introduce a publicly available full-sky beam convolution code library intended to inform the design of future cosmic microwave background instruments and help current experiments probe potential systematic effects. The code can be used to assess the impact of optical systematics on all stages of data reduction for a realistic experiment, including analyses beyond power spectrum estimation, by generating signal timelines that may serve as input to full analysis pipelines. The design and mathematical framework of the python code is discussed along with a few simple benchmarking results. We present a simple two-lens refracting telescope design and use it together with the code to simulate a year-long data set for 400 detectors scanning the sky on a satellite instrument. The simulation results identify a number of sub-leading optical non-idealities and demonstrate significant B-mode residuals caused by extended sidelobes that are sensitive to polarized radiation from the Galaxy. For the proposed design and satellite scanning strategy, we showthat a full physical optics beam model generates B-mode systematics that differ significantly from the simpler elliptical Gaussian model.

Original languageEnglish
Pages (from-to)5448-5467
Number of pages20
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
Publication statusPublished - 1 Jul 2019

Bibliographical note

Funding Information:
We are grateful to Katherine Freese and Martina Gerbino for helpful comments. AJD and JEG acknowledge support by Vetenskapsrådet (Swedish Research Council) through contract no. 638-2013-8993 and the Oskar Klein Centre for Cosmoparticle Physics. JEG acknowledges support from the Swedish National Space Agency (Rymdstyrelsen). Some computations have been performed at the Owl Cluster funded by the University of Oslo and the Research Council of Norway through grant 250672. Some of the results in this paper have been derived using the healpix (Górski et al. 2005) package.

Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

Other keywords

  • Cosmic Background Radiation
  • Cosmology: observations
  • Techniques: polarimetric
  • Telescopes


Dive into the research topics of 'Full-sky beam convolution for cosmic microwave background applications'. Together they form a unique fingerprint.

Cite this