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arXiv · 1301.5906

A simulation calibrated limit on the HI power spectrum from the GMRT Epoch of Reionization experiment

Gregory Paciga·Joshua G. Albert·Kevin Bandura·Tzu-Ching Chang·Yashwant Gupta·Christopher Hirata·Julia Odegova·Ue-Li Pen·Jeffrey B. Peterson·Jayanta Roy·Richard Shaw·Kris Sigurdson·Tabitha Voytek
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Abstract

The GMRT Epoch of Reionization (EoR) experiment is an ongoing effort to measure the power spectrum from neutral hydrogen at high redshift. We have previously reported an upper limit of (70 mK)^2 at wavenumbers of k=0.65 h/Mpc using a basic piecewise-linear foreground subtraction. In this paper we explore the use of a singular value decomposition to remove foregrounds with fewer assumptions about the foreground structure. Using this method we also quantify, for the first time, the signal loss due to the foreground filter and present new power spectra adjusted for this loss, providing a revised measurement of a 2-sigma upper limit at (248 mK)^2 for k=0.50 h/Mpc. While this revised limit is larger than previously reported, we believe it to be more robust and still represents the best current constraints on reionization at z=8.6.

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Gregory Paciga, Joshua G. Albert, Kevin Bandura, Tzu-Ching Chang, Yashwant Gupta, Christopher Hirata, Julia Odegova, Ue-Li Pen, Jeffrey B. Peterson, Jayanta Roy, Richard Shaw, Kris Sigurdson, Tabitha Voytek. 2013-05-13. A simulation calibrated limit on the HI power spectrum from the GMRT Epoch of Reionization experiment. https://doi.org/10.1093/mnras%2Fstt753

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