5 papers · 1 filter
The impact of lunar topography on the 21-cm power spectrum for grid-based arrays : Insights for the Dark-ages EXplorer (DEX)
S. Ghosh, L. V. E. Koopmans, C. Brinkerink +17
The Dark Ages (DA) provides a crucial window into the physics of the infant Universe, with the 21-cm signal offering the only direct probe for mapping out the three-dimensional dis…
Robust direction-dependent gain-calibration of beam-modelling errors far from the target field
S. A. Brackenhoff, A. R. Offringa, M. Mevius +8
Many astronomical questions require deep, wide-field observations at low radio frequencies. Phased arrays like LOFAR and SKA-low are designed for this, but have inherently unstable…
Extracting the Epoch of Reionization Signal with 3D U-Net Neural Networks Using Data-driven Systematic Effect Model
Li-Yang Gao, Léon V. E. Koopmans, Florent G. Mertens +11
Neutral hydrogen (HI) serves as a crucial probe for the Cosmic Dawn and the Epoch of Reionization (EoR). Actual observations of the 21-cm signal often encounter challenges such as…
Near-field imaging of local interference in radio interferometric data: Impact on the redshifted 21 cm power spectrum
S. Munshi, F. G. Mertens, L. V. E. Koopmans +24
Radio-frequency interference (RFI) is a major systematic limitation in radio astronomy, particularly for science cases requiring high sensitivity, such as 21 cm cosmology. Traditio…
Square Kilometre Array Science Data Challenge 3a: foreground removal for an EoR experiment
A. Bonaldi, P. Hartley, R. Braun +179
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 organis…