Bz components of magnetogram cutout used in the analysis and simulation taken at 11:36 UT on December 28, 2015 (the time when the eruption was observed). These are (a) the re-projected cutout where no masking is applied, (c) the re-projected cutout where masking is applied with a threshold of B ≤ 250 Mx cm⁻², (b) the simulation-ready cutouts produced with ELECTRICIT where no masking is applied, and (d) the simulation-ready cutouts produced with ELECTRICIT where masking is applied with a threshold of B ≤ 250 Mx cm⁻².