311 citations · 1.5k across the 29 of their papers we have counts for
9 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…
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…
Mitigating calibration errors from mutual coupling with time-domain filtering of 21 cm cosmological radio observations
N. Charles, N. S. Kern, R. Pascua +80
The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation (EoR). This has led to the construction of low-frequency radio i…
A novel radio imaging method for physical spectral index modelling
E. Ceccotti, A. R. Offringa, L. V. E. Koopmans +9
We present a new method, called "forced-spectrum fitting", for physically-based spectral modelling of radio sources during deconvolution. This improves upon current common deconvol…
Degree-Scale Galactic Radio Emission at 122 MHz around the North Celestial Pole with LOFAR-AARTFAAC
B. K. Gehlot, L. V. E. Koopmans, A. R. Offringa +11
Aims: Contamination from bright diffuse Galactic thermal and non-thermal radio emission poses crucial challenges in experiments aiming to measure the 21-cm signal of neutral hydrog…
Characterization of the AARTFAAC-12 aperture array: radio source counts at 42 and 61 MHz
A. Shulevski, T. M. O. Franzen, W. L. Williams +4
Dense aperture arrays provide key benefits in modern astrophysical research. They are flexible, employing cheap receivers, while relying on the ever more sophisticated compute back…
Precision requirements for interferometric gridding in 21-cm power spectrum analysis
A. R. Offringa, F. Mertens, S. van der Tol +4
We analyse the accuracy of radio interferometric gridding of visibilities with the aim to quantify the Epoch of Reionization (EoR) 21-cm power spectrum bias caused by gridding, ult…
The first power spectrum limit on the 21-cm signal of neutral hydrogen during the Cosmic Dawn at z=20-25 from LOFAR
B. K. Gehlot, F. G. Mertens, L. V. E. Koopmans +19
Observations of the redshifted 21-cm hyperfine line of neutral hydrogen from early phases of the Universe such as Cosmic Dawn and the Epoch of Reionization promise to open a new wi…
Polarization leakage in epoch of reionization windows: II. Primary beam model and direction dependent calibration
K. M. B. Asad, L. V. E. Koopmans, V. Jelić +11
Leakage of diffuse polarized emission into Stokes I caused by the polarized primary beam of the instrument might mimic the spectral structure of the 21-cm signal coming from the ep…