BeyondPlanck VIII. Efficient Sidelobe Convolution and Correction through Spin Harmonics
Abstract
We introduce a new formulation of the Conviqt convolution algorithm in terms of spin harmonics, and apply this to the problem of sidelobe correction for BeyondPlanck, the first end-to-end Bayesian Gibbs sampling framework for CMB analysis. We compare our implementation to the previous Planck LevelS implementation, and find good agreement between the two codes in terms of accuracy, but with a speed-up reaching a factor of 3--10, depending on the frequency bandlimits, and . The new algorithm is significantly simpler to implement and maintain, since all low-level calculations are handled through an external spherical harmonic transform library. We find that our mean sidelobe estimates for Planck LFI agree well with previous efforts. Additionally, we present novel sidelobe rms maps that quantify the uncertainty in the sidelobe corrections due to variations in the sky model.
Cite
@article{arxiv.2201.03478,
title = {BeyondPlanck VIII. Efficient Sidelobe Convolution and Correction through Spin Harmonics},
author = {M. Galloway and M. Reinecke and K. J. Andersen and R. Aurlien and R. Banerji and M. Bersanelli and S. Bertocco and M. Brilenkov and M. Carbone and L. P. L. Colombo and H. K. Eriksen and M. K. Foss and C. Franceschet and U. Fuskeland and S. Galeotta and S. Gerakakis and E. Gjerløw and B. Hensley and D. Herman and M. Iacobellis and M. Ieronymaki and H. T. Ihle and J. B. Jewell and A. Karakci and E. Keihänen and R. Keskitalo and G. Maggio and D. Maino and M. Maris and S. Paradiso and B. Partridge and A. -S. Suur-Uski and T. L. Svalheim and D. Tavagnacco and H. Thommesen and D. J. Watts and I. K. Wehus and A. Zacchei},
journal= {arXiv preprint arXiv:2201.03478},
year = {2023}
}
Comments
9 pages, 8 figures. Part of the BeyondPlanck paper suite