657 citations · 1.7k across the 25 of their papers we have counts for
25 papers
Exploring One-point Statistics in HERA Phase I Data: Effects of Foregrounds and Systematics on Measuring One-Point Statistics
Honggeun Kim, Jacqueline N. Hewitt, Nicholas S. Kern +61
Measuring one-point statistics in redshifted 21 cm intensity maps offers an opportunity to explore non-Gaussian features of the early universe. We assess the impact of instrumental…
Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data
Geoff G. Murphy, Philip Bull, Mario G. Santos +76
Observations with radio arrays that target the 21-cm signal originating from the early Universe suffer from a variety of systematic effects. An important class of these are reflect…
Direct Optimal Mapping Image Power Spectrum and its Window Functions
Zhilei Xu, Honggeun Kim, Jacqueline N. Hewitt +79
The key to detecting neutral hydrogen during the epoch of reionization (EoR) is to separate the cosmological signal from the dominating foreground radiation. We developed direct op…
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…
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…
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…
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…
HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
The HERA Collaboration, Zara Abdurashidova, James E. Aguirre +81
Recently, the Hydrogen Epoch of Reionization Array (HERA) collaboration has produced the experiment's first upper limits on the power spectrum of 21-cm fluctuations at z~8 and 10.…
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…
Detection of Cosmic Structures using the Bispectrum Phase. II. First Results from Application to Cosmic Reionization Using the Hydrogen Epoch of Reionization Array
Nithyanandan Thyagarajan, Chris L. Carilli, Bojan Nikolic +69
Characterizing the epoch of reionization (EoR) at via the redshifted 21 cm line of neutral Hydrogen (HI) is critical to modern astrophysics and cosmology, and thus a k…
Measuring HERA's primary beam in-situ: methodology and first results
Chuneeta D. Nunhokee, Aaron R. Parsons, Nicholas S. Kern +64
The central challenge in 21~cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the…
Foreground modelling via Gaussian process regression: an application to HERA data
Abhik Ghosh, Florent Mertens, Gianni Bernardi +70
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…
Redundant-Baseline Calibration of the Hydrogen Epoch of Reionization Array
Joshua S. Dillon, Max Lee, Zaki S. Ali +76
In 21 cm cosmology, precision calibration is key to the separation of the neutral hydrogen signal from very bright but spectrally-smooth astrophysical foregrounds. The Hydrogen Epo…
Mitigating Internal Instrument Coupling II: A Method Demonstration with the Hydrogen Epoch of Reionization Array
Nicholas S. Kern, Aaron R. Parsons, Joshua S. Dillon +63
We present a study of internal reflection and cross coupling systematics in Phase I of the Hydrogen Epoch of Reionization Array (HERA). In a companion paper, we outlined the mathem…
Absolute Calibration Strategies for the Hydrogen Epoch of Reionization Array and Their Impact on the 21 cm Power Spectrum
Nicholas S. Kern, Joshua S. Dillon, Aaron R. Parsons +69
We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Rei…
Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
Nicolas Fagnoni, Eloy de Lera Acedo, David R. DeBoer +67
The detection of the Epoch of Reionization (EoR) delay power spectrum using a "foreground avoidance method" highly depends on the instrument chromaticity. The systematic effects in…
Optimizing Sparse RFI Prediction using Deep Learning
Joshua Kerrigan, Paul La Plante, Saul Kohn +61
Radio Frequency Interference (RFI) is an ever-present limiting factor among radio telescopes even in the most remote observing locations. When looking to retain the maximum amount…
HI 21cm Cosmology and the Bi-spectrum: Closure Diagnostics in Massively Redundant Interferometric Arrays
C. L. Carilli, Bojan Nikolic, Nithyanandan Thyagarajan +62
New massively redundant low frequency arrays allow for a novel investigation of closure relations in interferometry. We employ commissioning data from the Hydrogen Epoch of Reioniz…
The Hydrogen Epoch of Reionization Array Dish III: Measuring Chromaticity of Prototype Element with Reflectometry
Nipanjana Patra, Aaron R. Parsons, David R. DeBoer +54
The experimental efforts to detect the redshifted 21 cm signal from the Epoch of Reionization (EoR) are limited predominantly by the chromatic instrumental systematic effect. The d…