A SENSITIVITY AND ARRAY-CONFIGURATION STUDY FOR MEASURING THE POWER SPECTRUM OF 21 cm EMISSION FROM REIONIZATION

By Aaron Parsons, Jonathan C. Pober, M. McQuinn, Daniel C. Jacobs, J. Aguirre. 2011

153 citations recorded by the source corpus.

Telescopes aiming to measure 21 cm emission from the Epoch of Reionization must toe a careful line, balancing the need for raw sensitivity against the stringent calibration requirements for removing bright foregrounds. It is unclear what the optimal design is for achieving both of these goals. Via a pedagogical derivation of an interferometer's response to the power spectrum of 21 cm reionization fluctuations, we show that even under optimistic scenarios first-generation arrays will yield low-signal-to-noise detections, and that different compact array configurations can substantially alter sensitivity. We explore the sensitivity gains of array configurations that yield high redundancy in the uv-plane—configurations that have been largely ignored since the advent of self-calibration for high-dynamic-range imaging. We first introduce a mathematical framework to generate optimal minimum-redundancy configurations for imaging. We contrast the sensitivity of such configurations with high-redundancy configurations, finding that high-redundancy configurations can improve power-spectrum sensitivity by more than an order of magnitude. We explore how high-redundancy array configurations can be tuned to various angular scales, enabling array sensitivity to be directed away from regions of the uv-plane (such as the origin) where foregrounds are brighter and instrumental systematics are more problematic. We demonstrate that a 132 antenna deployment of the Precision Array for Probing the Epoch of Reionization observing for 120 days in a high-redundancy configuration will, under ideal conditions, have the requisite sensitivity to detect the power spectrum of the 21 cm signal from reionization at a 3σ level at k < 0.25 h Mpc−1 in a bin of Δln k = 1. We discuss the tradeoffs of low- versus high-redundancy configurations.

Subfields: Aerospace Engineering, Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/8cbd09b9fc31d05bf2bf88620f554bd07d5d451f

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Citations in the corpus

The Evolution of the Intergalactic Medium (2015, background): “…signal (whose sensitivity owes to ∼ 103−104m2 of effective collecting area in a few hundred meter core) require integration times of hundreds of hours to reach sensitivity to the signal in standard reionization models (Morales 2005; McQuinn et al. 2006; Parsons et al. 2012; Beardsley et al. 2013).”
WHAT NEXT-GENERATION 21 cm POWER SPECTRUM MEASUREMENTS CAN TEACH US ABOUT THE EPOCH OF REIONIZATION (2013, methodology): “Although the frequency dependence of the primary beam enters into our sensitivity calculations in several places (including the pixel size in the uv plane), the dominant effect is to change the normalization of the noise level in Equation 1.”
A simulation-calibrated limit on the H i power spectrum from the GMRT Epoch of Reionization experiment (2013, background): “These foregrounds are currently one of the largest obstacles to detecting the 21 cm signal and several schemes have been developed to address the problem (e.g. Petrovic & Oh 2011; Liu & Tegmark 2011; Chapman et al. 2012; Parsons et al. 2012b; Dillon, Liu & Tegmark 2013).”
OPENING THE 21 cm EPOCH OF REIONIZATION WINDOW: MEASUREMENTS OF FOREGROUND ISOLATION WITH PAPER (2013, methodology): “We 14 Derivations of equation 1 in Morales (2005), McQuinn et al. (2006), and Parsons et al. (2012a), relate ΩB to an effective cosmological volume, using a top-hat primary beam or effective area as a pedagogical tool to simplify the result.”
ALL-SKY INTERFEROMETRY WITH SPHERICAL HARMONIC TRANSIT TELESCOPES (2013, methodology): “…new methods of interpreting and analysing the data from these revolutionary new instruments will be necessary to realize their scientific potential (Myers et al. 2003; Tegmark & Zaldarriaga 2009; Parsons & Backer 2009; Liu et al. 2010; Liu & Tegmark 2011; Parsons et al. 2012; Dillon et al. 2012).”
THE IMPACT OF POINT-SOURCE SUBTRACTION RESIDUALS ON 21 cm EPOCH OF REIONIZATION ESTIMATION (2012, methodology): “As well as the current design, Parsons et al. (2012) discussed the advantages of building maximally redundant instruments for EoR estimation, and one of their test designs will also be investigated in this work; a square 8 × 8 grid with antenna separation of 26.3 m (yielding the same maximum…”