Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced tri...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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CAMBRIDGE UNIV PRESS
2019
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/1905.07161 http://hdl.handle.net/20.500.11937/91578 |
| _version_ | 1848765553591713792 |
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| author | Trott, Cathryn Watkinson, C.A. Jordan, Chris Yoshiura, S. Majumdar, S. Barry, Nichole Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Line, Jack Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Murray, Steven Pindor, B. Pober, J.C. Rahimi, M. Riding, J. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Zheng, Q. Emrich, David Beardsley, A.P. Booler, Tom Crosse, B. Franzen, Thomas Horsley, L. Johnston-Hollitt, Melanie Kaplan, D.L. Kenney, David Pallot, D. Sleap, G. Steele, K. Walker, Mia Williams, Andrew Wu, C. |
| author_facet | Trott, Cathryn Watkinson, C.A. Jordan, Chris Yoshiura, S. Majumdar, S. Barry, Nichole Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Line, Jack Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Murray, Steven Pindor, B. Pober, J.C. Rahimi, M. Riding, J. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Zheng, Q. Emrich, David Beardsley, A.P. Booler, Tom Crosse, B. Franzen, Thomas Horsley, L. Johnston-Hollitt, Melanie Kaplan, D.L. Kenney, David Pallot, D. Sleap, G. Steele, K. Walker, Mia Williams, Andrew Wu, C. |
| author_sort | Trott, Cathryn |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167-197 MHz; z = 6.2-7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours. |
| first_indexed | 2025-11-14T11:37:05Z |
| format | Journal Article |
| id | curtin-20.500.11937-91578 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:37:05Z |
| publishDate | 2019 |
| publisher | CAMBRIDGE UNIV PRESS |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-915782023-05-16T03:16:26Z Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array Trott, Cathryn Watkinson, C.A. Jordan, Chris Yoshiura, S. Majumdar, S. Barry, Nichole Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Line, Jack Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Murray, Steven Pindor, B. Pober, J.C. Rahimi, M. Riding, J. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Zheng, Q. Emrich, David Beardsley, A.P. Booler, Tom Crosse, B. Franzen, Thomas Horsley, L. Johnston-Hollitt, Melanie Kaplan, D.L. Kenney, David Pallot, D. Sleap, G. Steele, K. Walker, Mia Williams, Andrew Wu, C. Science & Technology Physical Sciences Astronomy & Astrophysics cosmology early universe instrumentation methods statistical NON-GAUSSIANITY 21-CM COSMOLOGY astro-ph.CO astro-ph.CO astro-ph.IM We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167-197 MHz; z = 6.2-7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours. 2019 Journal Article http://hdl.handle.net/20.500.11937/91578 10.1017/pasa.2019.15 English https://arxiv.org/abs/1905.07161 http://purl.org/au-research/grants/arc/CE170100013 http://purl.org/au-research/grants/arc/FT180100196 http://purl.org/au-research/grants/arc/LE160100031 CAMBRIDGE UNIV PRESS restricted |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics cosmology early universe instrumentation methods statistical NON-GAUSSIANITY 21-CM COSMOLOGY astro-ph.CO astro-ph.CO astro-ph.IM Trott, Cathryn Watkinson, C.A. Jordan, Chris Yoshiura, S. Majumdar, S. Barry, Nichole Byrne, R. Hazelton, B.J. Hasegawa, K. Joseph, R. Kaneuji, T. Kubota, K. Li, W. Line, Jack Lynch, Christene McKinley, Ben Mitchell, D.A. Morales, M.F. Murray, Steven Pindor, B. Pober, J.C. Rahimi, M. Riding, J. Takahashi, K. Tingay, Steven Wayth, Randall Webster, R.L. Wilensky, M. Wyithe, J.S.B. Zheng, Q. Emrich, David Beardsley, A.P. Booler, Tom Crosse, B. Franzen, Thomas Horsley, L. Johnston-Hollitt, Melanie Kaplan, D.L. Kenney, David Pallot, D. Sleap, G. Steele, K. Walker, Mia Williams, Andrew Wu, C. Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array |
| title | Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array |
| title_full | Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array |
| title_fullStr | Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array |
| title_full_unstemmed | Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array |
| title_short | Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array |
| title_sort | gridded and direct epoch of reionisation bispectrum estimates using the murchison widefield array |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics cosmology early universe instrumentation methods statistical NON-GAUSSIANITY 21-CM COSMOLOGY astro-ph.CO astro-ph.CO astro-ph.IM |
| url | https://arxiv.org/abs/1905.07161 https://arxiv.org/abs/1905.07161 https://arxiv.org/abs/1905.07161 https://arxiv.org/abs/1905.07161 http://hdl.handle.net/20.500.11937/91578 |