Details

Autor(en) / Beteiligte

• Dillon, Joshua S.
• Liu, Adrian
• Williams, Christopher L.
• Hewitt, Jacqueline N.
• Tegmark, Max
• Morgan, Edward H.
• Levine, Alan M.
• Morales, Miguel F.
• Tingay, Steven J.
• Bernardi, Gianni
• Bowman, Judd D.
• Briggs, Frank H.
• Cappallo, Roger C.
• Emrich, David
• Mitchell, Daniel A.
• Oberoi, Divya
• Prabu, Thiagaraj
• Wayth, Randall
• Webster, Rachel L.

Titel

Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data

Ist Teil von

• Physical review. D, Particles, fields, gravitation, and cosmology, 2014-01, Vol.89 (2), Article 023002

Erscheinungsjahr

2014

Quelle

American Physical Society [PROLA]

Beschreibungen/Notizen

• 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 Delta (k) < 0.3 Kelvin at 95% confidence at a comoving scale k = 0.046 Mpc super(-1) and z = 9.5.