Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. We explore methods for robust estimation of the 21 cm signal from the Epoch of Reionization (EoR). A Kernel Density Estimator (KDE) is introduced for measuring the spatial temperature fluctuati...
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| Format: | Journal Article |
| Language: | English |
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OXFORD UNIV PRESS
2019
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| Online Access: | http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/80189 |
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| author | Trott, Cathryn Fu, Shih Ching Murray, Steven Jordan, Chris Line, Jack Barry, N. Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Pindor, B. Pober, J.C. Rahimi, M. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Yoshiura, S. Zheng, Q. Walker, Mia |
| author_facet | Trott, Cathryn Fu, Shih Ching Murray, Steven Jordan, Chris Line, Jack Barry, N. Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Pindor, B. Pober, J.C. Rahimi, M. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Yoshiura, S. Zheng, Q. Walker, Mia |
| author_sort | Trott, Cathryn |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
We explore methods for robust estimation of the 21 cm signal from the Epoch of Reionization (EoR). A Kernel Density Estimator (KDE) is introduced for measuring the spatial temperature fluctuation power spectrum from the EoR. The KDE estimates the underlying probability distribution function of fluctuations as a function of spatial scale, and contains different systematic biases and errors to the typical approach to estimating the fluctuation power spectrum. Extraction of histograms of visibilities allows moments analysis to be used to discriminate foregrounds from 21 cm signal and thermal noise. We use the information available in the histograms, along with the statistical dis-similarity of foregrounds from two independent observing fields, to robustly separate foregrounds from cosmological signal, while making no assumptions about the Gaussianity of the signal. Using two independent observing fields to robustly discriminate signal from foregrounds is crucial for the analysis presented in this paper. We apply the techniques to 13 h of Murchison Widefield Array EoR data over two observing fields. We compare the output to that obtained with a comparative power spectrum estimation method, and demonstrate the reduced foreground contamination using this approach. Using the second moment obtained directly from the KDE distribution functions yields a factor of 2-3 improvement in power for k < 0.3 h Mpc-1 compared with a matched delay space power estimator, while weighting data by additional statistics does not offer significant improvement beyond that available for thermal noise-only weights. |
| first_indexed | 2025-11-14T11:15:12Z |
| format | Journal Article |
| id | curtin-20.500.11937-80189 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:15:12Z |
| publishDate | 2019 |
| publisher | OXFORD UNIV PRESS |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-801892020-08-13T07:25:03Z Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization Trott, Cathryn Fu, Shih Ching Murray, Steven Jordan, Chris Line, Jack Barry, N. Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Pindor, B. Pober, J.C. Rahimi, M. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Yoshiura, S. Zheng, Q. Walker, Mia Science & Technology Physical Sciences Astronomy & Astrophysics instrumentation: interferometers methods: statistical NON-GAUSSIANITY © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. We explore methods for robust estimation of the 21 cm signal from the Epoch of Reionization (EoR). A Kernel Density Estimator (KDE) is introduced for measuring the spatial temperature fluctuation power spectrum from the EoR. The KDE estimates the underlying probability distribution function of fluctuations as a function of spatial scale, and contains different systematic biases and errors to the typical approach to estimating the fluctuation power spectrum. Extraction of histograms of visibilities allows moments analysis to be used to discriminate foregrounds from 21 cm signal and thermal noise. We use the information available in the histograms, along with the statistical dis-similarity of foregrounds from two independent observing fields, to robustly separate foregrounds from cosmological signal, while making no assumptions about the Gaussianity of the signal. Using two independent observing fields to robustly discriminate signal from foregrounds is crucial for the analysis presented in this paper. We apply the techniques to 13 h of Murchison Widefield Array EoR data over two observing fields. We compare the output to that obtained with a comparative power spectrum estimation method, and demonstrate the reduced foreground contamination using this approach. Using the second moment obtained directly from the KDE distribution functions yields a factor of 2-3 improvement in power for k < 0.3 h Mpc-1 compared with a matched delay space power estimator, while weighting data by additional statistics does not offer significant improvement beyond that available for thermal noise-only weights. 2019 Journal Article http://hdl.handle.net/20.500.11937/80189 10.1093/mnras/stz1207 English http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/LE160100031 OXFORD UNIV PRESS fulltext |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics instrumentation: interferometers methods: statistical NON-GAUSSIANITY Trott, Cathryn Fu, Shih Ching Murray, Steven Jordan, Chris Line, Jack Barry, N. Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Pindor, B. Pober, J.C. Rahimi, M. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Yoshiura, S. Zheng, Q. Walker, Mia Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization |
| title | Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization |
| title_full | Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization |
| title_fullStr | Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization |
| title_full_unstemmed | Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization |
| title_short | Robust statistics towards detection of the 21 cm signal from the Epoch of Reionization |
| title_sort | robust statistics towards detection of the 21 cm signal from the epoch of reionization |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics instrumentation: interferometers methods: statistical NON-GAUSSIANITY |
| url | http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/CE170100013 http://hdl.handle.net/20.500.11937/80189 |