Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array

Cathryn M. Trott, Catherine A. Watkinson, Christopher H. Jordan, Shintaro Yoshiura, Suman Majumdar, N. Barry, R. Byrne, B. J. Hazelton, K. Hasegawa, R. Joseph, T. Kaneuji, K. Kubota, W. Li, J. Line, C. Lynch, B. McKinley, D. A. Mitchell, M. F. Morales, S. Murray, B. Pindor & 25 others J. C. Pober, M. Rahimi, J. Riding, K. Takahashi, S. J. Tingay, R. B. Wayth, R. L. Webster, M. Wilensky, J. S.B. Wyithe, Q. Zheng, David Emrich, A. P. Beardsley, T. Booler, B. Crosse, T. M.O. Franzen, L. Horsley, M. Johnston-Hollitt, D. L. Kaplan, D. Kenney, D. Pallot, G. Sleap, K. Steele, M. Walker, A. Williams, C. Wu

Research output: Contribution to journalArticle

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Abstract

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.

Original languageEnglish
Article numbere023
JournalPublications of the Astronomical Society of Australia
Volume36
DOIs
Publication statusPublished - 18 Jul 2019

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time measurement
triangles
estimates
estimators
power spectra
configurations
future prospect
tiles
point sources
point source
antenna
antennas
output
prediction
predictions

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Trott, Cathryn M. ; Watkinson, Catherine A. ; Jordan, Christopher H. ; Yoshiura, Shintaro ; Majumdar, Suman ; Barry, N. ; Byrne, R. ; Hazelton, B. J. ; Hasegawa, K. ; Joseph, R. ; Kaneuji, T. ; Kubota, K. ; Li, W. ; Line, J. ; Lynch, C. ; McKinley, B. ; Mitchell, D. A. ; Morales, M. F. ; Murray, S. ; Pindor, B. ; Pober, J. C. ; Rahimi, M. ; Riding, J. ; Takahashi, K. ; Tingay, S. J. ; Wayth, R. B. ; Webster, R. L. ; Wilensky, M. ; Wyithe, J. S.B. ; Zheng, Q. ; Emrich, David ; Beardsley, A. P. ; Booler, T. ; Crosse, B. ; Franzen, T. M.O. ; Horsley, L. ; Johnston-Hollitt, M. ; Kaplan, D. L. ; Kenney, D. ; Pallot, D. ; Sleap, G. ; Steele, K. ; Walker, M. ; Williams, A. ; Wu, C. / Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array. In: Publications of the Astronomical Society of Australia. 2019 ; Vol. 36.
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abstract = "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.",
keywords = "cosmology, early universe, instrumentation, methods: statistical",
author = "Trott, {Cathryn M.} and Watkinson, {Catherine A.} and Jordan, {Christopher H.} and Shintaro Yoshiura and Suman Majumdar and N. Barry and R. Byrne and Hazelton, {B. J.} and K. Hasegawa and R. Joseph and T. Kaneuji and K. Kubota and W. Li and J. Line and C. Lynch and B. McKinley and Mitchell, {D. A.} and Morales, {M. F.} and S. Murray and B. Pindor and Pober, {J. C.} and M. Rahimi and J. Riding and K. Takahashi and Tingay, {S. J.} and Wayth, {R. B.} and Webster, {R. L.} and M. Wilensky and Wyithe, {J. S.B.} and Q. Zheng and David Emrich and Beardsley, {A. P.} and T. Booler and B. Crosse and Franzen, {T. M.O.} and L. Horsley and M. Johnston-Hollitt and Kaplan, {D. L.} and D. Kenney and D. Pallot and G. Sleap and K. Steele and M. Walker and A. Williams and C. Wu",
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language = "English",
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journal = "Publications of the Astronomincal Society of Australia (PASA)",
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publisher = "Cambridge University Press",

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Trott, CM, Watkinson, CA, Jordan, CH, Yoshiura, S, Majumdar, S, Barry, N, Byrne, R, Hazelton, BJ, Hasegawa, K, Joseph, R, Kaneuji, T, Kubota, K, Li, W, Line, J, Lynch, C, McKinley, B, Mitchell, DA, Morales, MF, Murray, S, Pindor, B, Pober, JC, Rahimi, M, Riding, J, Takahashi, K, Tingay, SJ, Wayth, RB, Webster, RL, Wilensky, M, Wyithe, JSB, Zheng, Q, Emrich, D, Beardsley, AP, Booler, T, Crosse, B, Franzen, TMO, Horsley, L, Johnston-Hollitt, M, Kaplan, DL, Kenney, D, Pallot, D, Sleap, G, Steele, K, Walker, M, Williams, A & Wu, C 2019, 'Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array' Publications of the Astronomical Society of Australia, vol. 36, e023. https://doi.org/10.1017/pasa.2019.15

Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array. / Trott, Cathryn M.; Watkinson, Catherine A.; Jordan, Christopher H.; Yoshiura, Shintaro; Majumdar, Suman; Barry, N.; Byrne, R.; Hazelton, B. J.; Hasegawa, K.; Joseph, R.; Kaneuji, T.; Kubota, K.; Li, W.; Line, J.; Lynch, C.; McKinley, B.; Mitchell, D. A.; Morales, M. F.; Murray, S.; Pindor, B.; Pober, J. C.; Rahimi, M.; Riding, J.; Takahashi, K.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Wilensky, M.; Wyithe, J. S.B.; Zheng, Q.; Emrich, David; Beardsley, A. P.; Booler, T.; Crosse, B.; Franzen, T. M.O.; Horsley, L.; Johnston-Hollitt, M.; Kaplan, D. L.; Kenney, D.; Pallot, D.; Sleap, G.; Steele, K.; Walker, M.; Williams, A.; Wu, C.

In: Publications of the Astronomical Society of Australia, Vol. 36, e023, 18.07.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array

AU - Trott, Cathryn M.

AU - Watkinson, Catherine A.

AU - Jordan, Christopher H.

AU - Yoshiura, Shintaro

AU - Majumdar, Suman

AU - Barry, N.

AU - Byrne, R.

AU - Hazelton, B. J.

AU - Hasegawa, K.

AU - Joseph, R.

AU - Kaneuji, T.

AU - Kubota, K.

AU - Li, W.

AU - Line, J.

AU - Lynch, C.

AU - McKinley, B.

AU - Mitchell, D. A.

AU - Morales, M. F.

AU - Murray, S.

AU - Pindor, B.

AU - Pober, J. C.

AU - Rahimi, M.

AU - Riding, J.

AU - Takahashi, K.

AU - Tingay, S. J.

AU - Wayth, R. B.

AU - Webster, R. L.

AU - Wilensky, M.

AU - Wyithe, J. S.B.

AU - Zheng, Q.

AU - Emrich, David

AU - Beardsley, A. P.

AU - Booler, T.

AU - Crosse, B.

AU - Franzen, T. M.O.

AU - Horsley, L.

AU - Johnston-Hollitt, M.

AU - Kaplan, D. L.

AU - Kenney, D.

AU - Pallot, D.

AU - Sleap, G.

AU - Steele, K.

AU - Walker, M.

AU - Williams, A.

AU - Wu, C.

PY - 2019/7/18

Y1 - 2019/7/18

N2 - 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.

AB - 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.

KW - cosmology

KW - early universe

KW - instrumentation

KW - methods: statistical

UR - http://www.scopus.com/inward/record.url?scp=85069482176&partnerID=8YFLogxK

U2 - 10.1017/pasa.2019.15

DO - 10.1017/pasa.2019.15

M3 - Article

VL - 36

JO - Publications of the Astronomincal Society of Australia (PASA)

JF - Publications of the Astronomincal Society of Australia (PASA)

SN - 1323-3580

M1 - e023

ER -