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Improved upper limits on the 21 cm signal power spectrum of neutral hydrogen at z ≈ 9.1 from LOFAR
(Oxford University Press, 2020)
A new upper limit on the 21 cm signal power spectrum at a redshift of z ≈ 9.1 is presented, based on 141 h of data obtained with the Low-Frequency Array (LOFAR). The analysis includes significant improvements in spectrally ...
Constraining the reionization history using deep learning from 21-cm tomography with the Square Kilometre Array
(Oxford University Press, 2020)
Upcoming 21-cm surveys with the SKA1-LOW telescope will enable imaging of the neutral hydrogen distribution on cosmological scales in the early Universe. These surveys are expected to generate huge imaging data sets that ...
Foreground modelling via Gaussian process regression: an application to HERA data
(Oxford University Press, 2020)
The key challenge in the observation of the redshifted 21-cm signal from cosmic reionization is its separation from the much brighter foreground emission. Such separation relies on the different spectral properties of the ...
Extracting the global signal from 21-cm fluctuations: the multitracer approach
(Oxford University Press, 2019)
The multitracer technique employs a ratio of densities of two differently biased galaxy samples that trace the same underlying matter density field, and was proposed to alleviate the cosmic variance problem. Here, we propose ...
Patterns of primary beam non-redundancy in close-packed 21 cm array observations
(Oxford University Press, 2021)
Radio interferometer arrays such as HERA consist of many close-packed dishes arranged in a regular pattern, giving rise to a
large number of ‘redundant’ baselines with the same length and orientation. Since identical ...