Square Kilometre Array Science Data Challenge 3a : foreground removal for an EoR experiment
Creators: name: Bonaldi, A.
name: Hartley, P.
name: Braun, R.
name: Purser, S.
name: Acharya, A.
name: Ahn, K.
name: Resco, M. Aparicio
name: Bait, O.
name: Bianco, M.
name: Chakraborty, A.
name: Chapman, E.
name: Chatterjee, S.
name: Chege, K.
name: Chen, H.
name: Chen, X.
name: Chen, Z.
name: Conaboy, L.
name: Cruz, M.
name: Darriba, L.
name: De Santis, M.
name: Denzel, P.
name: Diao, K.
name: Feron, J.
name: Finlay, C.
name: Gehlot, B.
name: Ghosh, S.
name: Giri, S. K.
name: Grumitt, R.
name: Hong, S. E.
name: Ito, T.
name: Jiang, M.
name: Jordan, C.
name: Kim, S.
name: Kim, M.
name: Kim, J.
name: Krishna, S. P.
name: Kulkarni, A.
name: López-Caniego, M.
name: Labadie-García, I.
name: Lee, H.
name: Lee, D.
name: Lee, N.
name: Line, J.
name: Liu, Y.
name: Mao, Y.
name: Mazumder, A.
name: Mertens, F. G.
name: Munshi, S.
name: Nasirudin, A.
name: Ni, S.
name: Nistane, V.
name: Norregaard, C.
name: Null, D.
name: Offringa, A.
name: Oh, M.
name: Oh, S. -H.
name: Parkinson, D.
name: Pritchard, J.
name: Ruiz-Granda, M.
name: López, V. Salvador
name: Shan, H.
name: Sharma, R.
name: Trott, C.
name: Yoshiura, S.
name: Zhang, L.
name: Zhang, X.
name: Zheng, Q.
name: Zhu, Z.
name: Zuo, S.
name: Akahori, T.
name: Alberto, P.
name: Allys, E.
name: An, T.
name: Anstey, D.
name: Baek, J.
name: Basavraj
name: Brackenhoff, S.
name: Browne, P.
name: Ceccotti, E.
name: Chen, H.
name: Chen, T.
name: Choudhuri, S.
name: Choudhury, M.
name: Coles, J.
name: Cook, J.
name: Cornu, D.
name: Cunnington, S.
name: Das, S.
name: Acedo, E. De Lera
name: Delou is, J. -M.
name: Deng, F.
name: Ding, J.
name: Elahi, K. M. A.
name: Fernandez, P.
name: Fernández, C.
name: Alcázar, A. Fernández
name: Galluzzi, V.
name: Gao, L. -Y.
name: Garain, U.
name: Garrido, J.
name: Gendron-Marsolais, M. -L.
name: Gessey-Jones, T.
name: Ghorbel, H.
name: Gong, Y.
name: Guo, S.
name: Hasegawa, K.
name: Hayashi, T.
name: Herranz, D.
name: Holanda, V.
name: Holloway, A. J.
name: Hothi, I.
name: Höfer, C.
name: Jelić, V.
name: Jiang, Y.
name: Jiang, X.
name: Kang, H.
name: Kim, J. -Y.
name: Koopmans, L. V.
name: Lacroix, R.
name: Lee, E.
name: Leeney, S.
name: Levrier, F.
name: Li, Y.
name: Liu, Y.
name: Ma, Q.
name: Meriot, R.
name: Mesinger, A.
name: Mevius, M.
name: Minoda, T.
name: Miville-Deschenes, M. -A.
name: Moldon, J.
name: Mondal, R.
name: Murmu, C.
name: Murray, S.
name: SR, Nirmala
name: Niu, Q .
name: Nunhokee, C.
name: O'Hara, O.
name: Pal, S. K.
name: Pal, S.
name: Park, J.
name: Parra, M.
name: tra, N. N. Pa
name: Pindor, B.
name: Remazeilles, M.
name: Rey, P.
name: Rubino-Martin, J. A.
name: Saha, S.
name: Selvaraj, A.
name: Semelin, B.
name: Shah, R.
name: Shao, Y.
name: Shaw, A. K.
name: Shi, F.
name: Shimabukuro, H.
name: Singh, G.
name: Sohn, B. W.
name: Stagni, M.
name: Starck, J. -L.
name: Sui, C.
name: Swinbank, J. D.
name: Sánchez, J.
name: Sánchez-Expósito, S.
name: Takahashi, K.
name: Takeuchi, T.
name: Tripathi, A.
name: Verdes-Montenegro, L.
name: Vielva, P.
name: Vitello, F. R.
name: Wang, G. -J.
name: Wang, Q.
name: Wang, X.
name: Wang, Y.
name: Wang, Y. -X.
name: Wiegert, T.
name: Wild, A.
name: Williams, W. L.
name: Wolz, L.
name: Wu, X.
name: Wu, P.
name: Xia, J. -Q.
name: Xu, Y.
name: Yan, R.
name: Yan, Y. -P.
Publisher: name: arXiv
Year: 2025
Subjects: Interferometer
Data analysis
Dark ages
Reionization
First stars
006: Spezielle Computerverfahren

description: 29 pages, 10 figures, submitted to MNRAS
description: We present and analyse the results of the Science data challenge 3a (SDC3a, https://sdc3.skao.int/challenges/foregrounds), an EoR foreground-removal community-wide exercise organised by the Square Kilometre Array Observatory (SKAO). The challenge ran for 8 months, from March to October 2023. Participants were provided with realistic simulations of SKA-Low data between 106MHz and 196 MHz, including foreground contamination from extragalactic as well as Galactic emission, instrumental and systematic effects. They were asked to deliver cylindrical power spectra of the EoR signal, cleaned from all corruptions, and the corresponding confidence levels. Here we describe the approaches taken by the 17 teams that completed the challenge, and we assess their performance using different metrics. The challenge results provide a positive outlook on the capabilities of current foreground-mitigation approaches to recover the faint EoR signal from SKA-Low observations. The median error committed in the EoR power spectrum recovery is below the true signal for seven teams, although in some cases there are some significant outliers. The smallest residual overall is 4.2+20
−4.2 × 10−4 K2h−3cMpc3 across all considered scales and frequencies. The estimation of confidence levels provided by the teams is overall less accurate, with the true error being typically underestimated, sometimes very significantly. The most accurate error bars account for 60 ± 20% of the true errors committed. The challenge results provide a means for all teams to understand and improve their performance. This challenge indicates that the comparison between independent pipelines could be a powerful tool to assess residual biases and improve error estimation.