A method for 21 cm power spectrum estimation in the presence of foregrounds
Name
Liu-2011-A method for 21 cm p.pdf
Size
3 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Liu, Adrian Chi-Yan
Tegmark, Max Erik
Date Issued
May 2011
Journal
Physcial Review D
Publisher
American Physical Society
Citation
Liu, Adrian, and Max Tegmark. “A Method for 21 Cm Power Spectrum Estimation in the Presence of Foregrounds.” Physical Review D 83.10 (2011) © 2011 American Physical Society
Version
Final published version
Abstract
The technique of 21 cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a cosmological power spectrum from beneath overwhelmingly large sources of foreground contamination. In this paper, we develop a unified matrix-based framework for foreground subtraction and power spectrum estimation, which allows us to quantify the errors and biases that arise in the power spectrum as a result of foreground subtraction. We find that existing line-of-sight foreground subtraction proposals can lead to substantial mode mixing as well as residual noise and foreground biases, whereas our proposed inverse-variance foreground subtraction eliminates noise and foreground biases, gives smaller error bars, and produces less correlated measurements of the power spectrum. We also numerically confirm the intuitive belief in the literature that 21 cm foreground subtraction is best done using frequency rather than angular information.
MIT Department
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1103/PhysRevD.83.103006
