Coffee talks
Wednesday 06/12/2023 @ 14:30, Sala riunioni quarto piano e on-line (meet.google.com/sue-bwvk-axf)
Ridhima Nunhokee (Curtin University, Australia), "Battling through systematics for EoR experiments with the MWA"
The key challenge in 21 cm cosmology is the presence of bright astrophysical foregrounds, few orders of magnitude greater than the 21 cm hydrogen line. Subtraction and avoidance techniques are fundamentally used to mitigate the impact of these foregrounds. Both methods are sensitive to systematics present in the data and past studies have shown the influence of residual systematics on the 21 cm power spectrum. It is therefore imperial to identify and alleviate them. In this work, we use observations from Phase I configurations of the Murchison Widefield Array (MWA), that sums up to about 338 hours. We develop a framework that derives various statistical metrics from data products, aiding in identifying misbehaving antennas, corrupted timestamps, and frequencies and thus, allowing to single out RFI and systematics dominated observations. In this talk, I will present the improved data processing pipeline and power spectrum results obtained using the Cosmological H1 Power Spectrum Estimator (CHIPS) after systematic mitigation.