530 citations · 4.6k across the 76 of their papers we have counts for
81 papers
Beyond ΛCDM with the SKA Observatory -- I: Probing Gravity on Cosmological Scales
S. Camera, C. Addis, S. L. Guedezounme +26
General relativity (GR) is currently the best description of the gravitational interaction at our disposal and is one of the foundations of the concordance cosmological model. For…
Search for the Epoch of Reionisation with HERA: Upper Limits on the Closure Phase Delay Power Spectrum
Pascal M. Keller, Bojan Nikolic, Nithyanandan Thyagarajan +80
Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to sep…
The foreground transfer function for HI intensity mapping signal reconstruction: MeerKLASS and precision cosmology applications
Steven Cunnington, Laura Wolz, Philip Bull +8
Blind cleaning methods are currently the preferred strategy for handling foreground contamination in single-dish HI intensity mapping surveys. Despite the increasing sophistication…
Statistical recovery of 21cm visibilities and their power spectra with Gaussian constrained realisations and Gibbs sampling
Fraser Kennedy, Philip Bull, Michael Wilensky +2
Radio interferometers designed to probe the 21cm signal from Cosmic Dawn and the Epoch of Reionisation must contend with systematic effects that make it difficult to achieve suffic…
Bayesian jackknife tests with a small number of subsets: Application to HERA 21cm power spectrum upper limits
Michael J. Wilensky, Fraser Kennedy, Philip Bull +2
We present a Bayesian jackknife test for assessing the probability that a data set contains biased subsets, and, if so, which of the subsets are likely to be biased. The test can b…
Characterization Of Inpaint Residuals In Interferometric Measurements of the Epoch Of Reionization
Michael Pagano, Jing Liu, Adrian Liu +75
Radio Frequency Interference (RFI) is one of the systematic challenges preventing 21cm interferometric instruments from detecting the Epoch of Reionization. To mitigate the effects…
Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
The HERA Collaboration, Zara Abdurashidova, Tyrone Adams +92
We report the most sensitive upper limits to date on the 21 cm epoch of reionization power spectrum using 94 nights of observing with Phase I of the Hydrogen Epoch of Reionization…
Impact of instrument and data characteristics in the interferometric reconstruction of the 21 cm power spectrum
Adélie Gorce, Samskruthi Ganjam, Adrian Liu +75
Combining the visibilities measured by an interferometer to form a cosmological power spectrum is a complicated process. In a delay-based analysis, the mapping between instrumental…
Characterizing line-of-sight variability of polarized dust emission with future CMB experiments
Lisa McBride, Philip Bull, Brandon S. Hensley
Galactic dust emission is often accounted for in cosmic microwave background (CMB) analyses by fitting a simple two-parameter modified blackbody (MBB) model in each pixel, which no…
HI intensity mapping with MeerKAT: power spectrum detection in cross-correlation with WiggleZ galaxies
Steven Cunnington, Yichao Li, Mario G. Santos +13
We present a detection of correlated clustering between MeerKAT radio intensity maps and galaxies from the WiggleZ Dark Energy Survey. We find a detection of the cross-corre…
Direct Optimal Mapping for 21cm Cosmology: A Demonstration with the Hydrogen Epoch of Reionization Array
Zhilei Xu, Jacqueline N. Hewitt, Kai-Feng Chen +78
Motivated by the desire for wide-field images with well-defined statistical properties for 21cm cosmology, we implement an optimal mapping pipeline that computes a maximum likeliho…
Measurements of the diffuse Galactic synchrotron spectral index and curvature from MeerKLASS pilot data
Melis O. Irfan, Philip Bull, Mario G. Santos +6
21cm intensity mapping experiments are bringing an influx of high spectral resolution observational data in the MHz GHz regime. We use pilot MHz data fro…
Automated Detection of Antenna Malfunctions in Large-N Interferometers: A Case Study with the Hydrogen Epoch of Reionization Array
Dara Storer, Joshua S. Dillon, Daniel C. Jacobs +75
We present a framework for identifying and flagging malfunctioning antennas in large radio interferometers. We outline two distinct categories of metrics designed to detect outlier…
First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
The HERA Collaboration, Zara Abdurashidova, James E. Aguirre +74
We report upper-limits on the Epoch of Reionization (EoR) 21 cm power spectrum at redshifts 7.9 and 10.4 with 18 nights of data ( hours of integration) from Phase I of the…
Spin-based removal of instrumental systematics in 21cm intensity mapping surveys
Nialh McCallum, Daniel B. Thomas, Philip Bull +1
Upcoming cosmological intensity mapping surveys will open new windows on the Universe, but they must first overcome a number of significant systematic effects, including polarizati…
Cleaning foregrounds from single-dish 21cm intensity maps with Kernel Principal Component Analysis
Melis O. Irfan, Philip Bull
The high dynamic range between contaminating foreground emission and the fluctuating 21cm brightness temperature field is one of the most problematic characteristics of 21cm intens…
Validation of the HERA Phase I Epoch of Reionization 21 cm Power Spectrum Software Pipeline
James E. Aguirre, Steven G. Murray, Robert Pascua +73
We describe the validation of the HERA Phase I software pipeline by a series of modular tests, building up to an end-to-end simulation. The philosophy of this approach is to valida…
Effects of model incompleteness on the drift-scan calibration of radio telescopes
Bharat K. Gehlot, Daniel C. Jacobs, Judd D. Bowman +76
Precision calibration poses challenges to experiments probing the redshifted 21-cm signal of neutral hydrogen from the Cosmic Dawn and Epoch of Reionization (z~30-6). In both inter…
A Real Time Processing System for Big Data in Astronomy: Applications to HERA
Paul La Plante, Peter K. G. Williams, Matthew Kolopanis +72
As current- and next-generation astronomical instruments come online, they will generate an unprecedented deluge of data. Analyzing these data in real time presents unique conceptu…
Methods of Error Estimation for Delay Power Spectra in Cosmology
Jianrong Tan, Adrian Liu, Nicholas S. Kern +71
Precise measurements of the 21 cm power spectrum are crucial for understanding the physical processes of hydrogen reionization. Currently, this probe is being pursued by low-freque…
Statistical recovery of the BAO scale from multipoles of the beam-convolved 21cm correlation function
Fraser Kennedy, Philip Bull
Despite being designed as an interferometer, the MeerKAT radio array (an SKA pathfinder) can also be used in autocorrelation (`single-dish') mode, where each dish scans the sky ind…
Patterns of primary beam non-redundancy in close-packed 21 cm array observations
Samir Choudhuri, Philip Bull, Hugh Garsden
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 len…
HI intensity mapping with MeerKAT: Calibration pipeline for multi-dish autocorrelation observations
Jingying Wang, Mario G. Santos, Philip Bull +10
While most purpose-built 21cm intensity mapping experiments are close-packed interferometer arrays, general-purpose dish arrays should also be capable of measuring the cosmological…
Observing relativistic features in large-scale structure surveys -- II: Doppler magnification in an ensemble of relativistic simulations
Louis Coates, Julian Adamek, Philip Bull +2
The standard cosmological model is inherently relativistic, and yet a wide range of cosmological observations can be predicted accurately from essentially Newtonian theory. This is…