Title:	Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data
Authors:	Dillon, Joshua S. Liu, Adrian Prabu, T. +16 Co-authors
Issue Date:	Jan-2014
Publisher:	American Physical Society
Citation:	Physical Review D, 2014, Vol.89, p23002
Abstract:	We present techniques for bridging the gap between idealized inverse covariance weighted quadratic estimation of 21 cm power spectra and the real-world challenges presented universally by interferometric observation. By carefully evaluating various estimators and adapting our techniques for large but incomplete data sets, we develop a robust power spectrum estimation framework that preserves the so-called "Epoch of Reionization (EoR) window" and keeps track of estimator errors and covariances. We apply our method to observations from the 32-tile prototype of the Murchinson Widefield Array to demonstrate the importance of a judicious analysis technique. Lastly, we apply our method to investigate the dependence of the clean EoR window on frequency—especially the frequency dependence of the so-called “wedge" feature—and establish upper limits on the power spectrum from z=6.2 to z=11.7. Our lowest limit is Δ(k)<0.3 Kelvin at 95% confidence at a comoving scale k=0.046  Mpc−1 and z=9.5.
Description:	Open Access
URI:	http://hdl.handle.net/2289/5869
ISSN:	1550-7998 1550-2368(Online)
Alternative Location:	http://adsabs.harvard.edu/abs/2014PhRvD..89b3002D http://arxiv.org/abs/1304.4229 http://dx.doi.org/10.1103/PhysRevD.89.023002
Copyright:	2014 American Physical Society
Appears in Collections:	Research Papers (A&A)

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