BeyondPlanck. III. Commander3

M. Galloway, K. J. Andersen, R. Aurlien, R. Banerji, M. Bersanelli, S. Bertocco, M. Brilenkov, M. Carbone, L. P. L. Colombo, H. K. Eriksen, J. R. Eskilt, M. K. Foss (+5 others)
2022 Astronomy and Astrophysics  
We describe the computational infrastructure for end-to-end Bayesian Cosmic Microwave Background (CMB) analysis implemented by the BeyondPlanck collaboration. The code is called Commander3. It provides a statistically consistent framework for global analysis of CMB and microwave observations and may be useful for a wide range of legacy, current, and future experiments. The paper has three main goals. Firstly, we provide a high-level overview of the existing code base, aiming to guide readers
more » ... wish to extend and adapt the code according to their own needs or re-implement it from scratch in a different programming language. Secondly, we discuss some critical computational challenges that arise within any global CMB analysis framework, for instance inmemory compression of time-ordered data, fast Fourier transform optimization, and parallelization and load-balancing. Thirdly, we quantify the CPU and RAM requirements for the current BeyondPlanck analysis, finding that a total of 1.5 TB of RAM is required for efficient analysis and that the total cost of a full Gibbs sample for LFI is 170 CPU-hrs, including both low-level processing and high-level component separation, which is well within the capabilities of current low-cost computing facilities. The existing code base is made publicly available under a GNU General Public Library (GPL) license.
doi:10.1051/0004-6361/202243137 fatcat:tdjosi5hnrfsze4zgk34vxzx5a