First limits on the 21 cm power spectrum during the Epoch of X-ray heating

A. Ewall-Wice, J.S. Dillon, J.N. Hewitt, A. Loeb, A. Mesinger, A.R. Neben, A.R. Offringa, M. Tegmark, N. Barry, A.P. Beardsley, G. Bernardi, J.D. Bowman, F. Briggs, R.J. Cappallo, P. Carroll, B.E. Corey, A. De Oliveira-Costa, D. Emrich, L. Feng, B.M. Gaensler & 45 others R. Goeke, L.J. Greenhill, B.J. Hazelton, N. Hurley-Walker, M. Johnston-Hollitt, D.C. Jacobs, D.L. Kaplan, J.C. Kasper, H.S. Kim, E. Kratzenberg, E. Lenc, J. Line, C.J. Lonsdale, M.J. Lynch, B. Mckinley, S.R. Mcwhirter, D.A. Mitchell, M.F. Morales, E. Morgan, N. Thyagarajan, D. Oberoi, S.M. Ord, S. Paul, B. Pindor, J.C. Pober, T. Prabu, P. Procopio, J. Riding, A.E.E. Rogers, A. Roshi, N. Udaya Shankar, S.K. Sethi, K.S. Srivani, R. Subrahmanyan, I.S. Sullivan, S.J. Tingay, C.M. Trott, M. Waterson, R.B. Wayth, R.L. Webster, A.R. Whitney, A. Williams, C.L. Williams, Chen Wu, J.S.B. Wyithe

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

© 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. We present first results from radio observations with the Murchison Widefield Array seeking to constrain the power spectrum of 21 cm brightness temperature fluctuations between the redshifts of 11.6 and 17.9 (113 and 75 MHz). 3 h of observations were conducted over two nights with significantly different levels of ionospheric activity. We use these data to assess the impact of systematic errors at low frequency, including the ionosphere and radio-frequency interference, on a power spectrum measurement. We find that after the 1-3 h of integration presented here, our measurements at the Murchison Radio Observatory are not limited by RFI, even within the FMband, and that the ionosphere does not appear to affect the level of power in the modes that we expect to be sensitive to cosmology. Power spectrum detections, inconsistent with noise, due to fine spectral structure imprinted on the foregrounds by reflections in the signal-chain, occupy the spatial Fourier modes where we would otherwise be most sensitive to the cosmological signal. We are able to reduce this contamination using calibration solutions derived from autocorrelations so that we achieve an sensitivity of 104 mK on comoving scales k?0.5 h Mpc-1. This represents the first upper limits on the 21 cmpower spectrum fluctuations at redshifts 12 ? z ? 18 but is still limited by calibration systematics. While calibration improvements may allow us to further remove this contamination, our results emphasize that future experiments should consider carefully the existence of and their ability to calibrate out any spectral structure within the EoR window.
Original languageEnglish
Pages (from-to)4320-4347
JournalMonthly Notices of the Royal Astronomical Society
Volume460
Issue number4
DOIs
Publication statusPublished - 2016

Fingerprint

power spectra
time measurement
heating
ionospheres
contamination
radio
resin film infusion
calibration
radio frequency interference
ionosphere
x rays
radio observation
brightness temperature
systematic errors
night
ionospherics
autocorrelation
cosmology
observatories
low frequencies

Cite this

Ewall-Wice, A., Dillon, J. S., Hewitt, J. N., Loeb, A., Mesinger, A., Neben, A. R., ... Wyithe, J. S. B. (2016). First limits on the 21 cm power spectrum during the Epoch of X-ray heating. Monthly Notices of the Royal Astronomical Society, 460(4), 4320-4347. https://doi.org/10.1093/mnras/stw1022
Ewall-Wice, A. ; Dillon, J.S. ; Hewitt, J.N. ; Loeb, A. ; Mesinger, A. ; Neben, A.R. ; Offringa, A.R. ; Tegmark, M. ; Barry, N. ; Beardsley, A.P. ; Bernardi, G. ; Bowman, J.D. ; Briggs, F. ; Cappallo, R.J. ; Carroll, P. ; Corey, B.E. ; De Oliveira-Costa, A. ; Emrich, D. ; Feng, L. ; Gaensler, B.M. ; Goeke, R. ; Greenhill, L.J. ; Hazelton, B.J. ; Hurley-Walker, N. ; Johnston-Hollitt, M. ; Jacobs, D.C. ; Kaplan, D.L. ; Kasper, J.C. ; Kim, H.S. ; Kratzenberg, E. ; Lenc, E. ; Line, J. ; Lonsdale, C.J. ; Lynch, M.J. ; Mckinley, B. ; Mcwhirter, S.R. ; Mitchell, D.A. ; Morales, M.F. ; Morgan, E. ; Thyagarajan, N. ; Oberoi, D. ; Ord, S.M. ; Paul, S. ; Pindor, B. ; Pober, J.C. ; Prabu, T. ; Procopio, P. ; Riding, J. ; Rogers, A.E.E. ; Roshi, A. ; Udaya Shankar, N. ; Sethi, S.K. ; Srivani, K.S. ; Subrahmanyan, R. ; Sullivan, I.S. ; Tingay, S.J. ; Trott, C.M. ; Waterson, M. ; Wayth, R.B. ; Webster, R.L. ; Whitney, A.R. ; Williams, A. ; Williams, C.L. ; Wu, Chen ; Wyithe, J.S.B. / First limits on the 21 cm power spectrum during the Epoch of X-ray heating. In: Monthly Notices of the Royal Astronomical Society. 2016 ; Vol. 460, No. 4. pp. 4320-4347.
@article{67fb84e1ed1c4e0c8413fb57cdcc2649,
title = "First limits on the 21 cm power spectrum during the Epoch of X-ray heating",
abstract = "{\circledC} 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. We present first results from radio observations with the Murchison Widefield Array seeking to constrain the power spectrum of 21 cm brightness temperature fluctuations between the redshifts of 11.6 and 17.9 (113 and 75 MHz). 3 h of observations were conducted over two nights with significantly different levels of ionospheric activity. We use these data to assess the impact of systematic errors at low frequency, including the ionosphere and radio-frequency interference, on a power spectrum measurement. We find that after the 1-3 h of integration presented here, our measurements at the Murchison Radio Observatory are not limited by RFI, even within the FMband, and that the ionosphere does not appear to affect the level of power in the modes that we expect to be sensitive to cosmology. Power spectrum detections, inconsistent with noise, due to fine spectral structure imprinted on the foregrounds by reflections in the signal-chain, occupy the spatial Fourier modes where we would otherwise be most sensitive to the cosmological signal. We are able to reduce this contamination using calibration solutions derived from autocorrelations so that we achieve an sensitivity of 104 mK on comoving scales k?0.5 h Mpc-1. This represents the first upper limits on the 21 cmpower spectrum fluctuations at redshifts 12 ? z ? 18 but is still limited by calibration systematics. While calibration improvements may allow us to further remove this contamination, our results emphasize that future experiments should consider carefully the existence of and their ability to calibrate out any spectral structure within the EoR window.",
author = "A. Ewall-Wice and J.S. Dillon and J.N. Hewitt and A. Loeb and A. Mesinger and A.R. Neben and A.R. Offringa and M. Tegmark and N. Barry and A.P. Beardsley and G. Bernardi and J.D. Bowman and F. Briggs and R.J. Cappallo and P. Carroll and B.E. Corey and {De Oliveira-Costa}, A. and D. Emrich and L. Feng and B.M. Gaensler and R. Goeke and L.J. Greenhill and B.J. Hazelton and N. Hurley-Walker and M. Johnston-Hollitt and D.C. Jacobs and D.L. Kaplan and J.C. Kasper and H.S. Kim and E. Kratzenberg and E. Lenc and J. Line and C.J. Lonsdale and M.J. Lynch and B. Mckinley and S.R. Mcwhirter and D.A. Mitchell and M.F. Morales and E. Morgan and N. Thyagarajan and D. Oberoi and S.M. Ord and S. Paul and B. Pindor and J.C. Pober and T. Prabu and P. Procopio and J. Riding and A.E.E. Rogers and A. Roshi and {Udaya Shankar}, N. and S.K. Sethi and K.S. Srivani and R. Subrahmanyan and I.S. Sullivan and S.J. Tingay and C.M. Trott and M. Waterson and R.B. Wayth and R.L. Webster and A.R. Whitney and A. Williams and C.L. Williams and Chen Wu and J.S.B. Wyithe",
year = "2016",
doi = "10.1093/mnras/stw1022",
language = "English",
volume = "460",
pages = "4320--4347",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "OXFORD UNIV PRESS UNITED KINGDOM",
number = "4",

}

Ewall-Wice, A, Dillon, JS, Hewitt, JN, Loeb, A, Mesinger, A, Neben, AR, Offringa, AR, Tegmark, M, Barry, N, Beardsley, AP, Bernardi, G, Bowman, JD, Briggs, F, Cappallo, RJ, Carroll, P, Corey, BE, De Oliveira-Costa, A, Emrich, D, Feng, L, Gaensler, BM, Goeke, R, Greenhill, LJ, Hazelton, BJ, Hurley-Walker, N, Johnston-Hollitt, M, Jacobs, DC, Kaplan, DL, Kasper, JC, Kim, HS, Kratzenberg, E, Lenc, E, Line, J, Lonsdale, CJ, Lynch, MJ, Mckinley, B, Mcwhirter, SR, Mitchell, DA, Morales, MF, Morgan, E, Thyagarajan, N, Oberoi, D, Ord, SM, Paul, S, Pindor, B, Pober, JC, Prabu, T, Procopio, P, Riding, J, Rogers, AEE, Roshi, A, Udaya Shankar, N, Sethi, SK, Srivani, KS, Subrahmanyan, R, Sullivan, IS, Tingay, SJ, Trott, CM, Waterson, M, Wayth, RB, Webster, RL, Whitney, AR, Williams, A, Williams, CL, Wu, C & Wyithe, JSB 2016, 'First limits on the 21 cm power spectrum during the Epoch of X-ray heating' Monthly Notices of the Royal Astronomical Society, vol. 460, no. 4, pp. 4320-4347. https://doi.org/10.1093/mnras/stw1022

First limits on the 21 cm power spectrum during the Epoch of X-ray heating. / Ewall-Wice, A.; Dillon, J.S.; Hewitt, J.N.; Loeb, A.; Mesinger, A.; Neben, A.R.; Offringa, A.R.; Tegmark, M.; Barry, N.; Beardsley, A.P.; Bernardi, G.; Bowman, J.D.; Briggs, F.; Cappallo, R.J.; Carroll, P.; Corey, B.E.; De Oliveira-Costa, A.; Emrich, D.; Feng, L.; Gaensler, B.M.; Goeke, R.; Greenhill, L.J.; Hazelton, B.J.; Hurley-Walker, N.; Johnston-Hollitt, M.; Jacobs, D.C.; Kaplan, D.L.; Kasper, J.C.; Kim, H.S.; Kratzenberg, E.; Lenc, E.; Line, J.; Lonsdale, C.J.; Lynch, M.J.; Mckinley, B.; Mcwhirter, S.R.; Mitchell, D.A.; Morales, M.F.; Morgan, E.; Thyagarajan, N.; Oberoi, D.; Ord, S.M.; Paul, S.; Pindor, B.; Pober, J.C.; Prabu, T.; Procopio, P.; Riding, J.; Rogers, A.E.E.; Roshi, A.; Udaya Shankar, N.; Sethi, S.K.; Srivani, K.S.; Subrahmanyan, R.; Sullivan, I.S.; Tingay, S.J.; Trott, C.M.; Waterson, M.; Wayth, R.B.; Webster, R.L.; Whitney, A.R.; Williams, A.; Williams, C.L.; Wu, Chen; Wyithe, J.S.B.

In: Monthly Notices of the Royal Astronomical Society, Vol. 460, No. 4, 2016, p. 4320-4347.

Research output: Contribution to journalArticle

TY - JOUR

T1 - First limits on the 21 cm power spectrum during the Epoch of X-ray heating

AU - Ewall-Wice, A.

AU - Dillon, J.S.

AU - Hewitt, J.N.

AU - Loeb, A.

AU - Mesinger, A.

AU - Neben, A.R.

AU - Offringa, A.R.

AU - Tegmark, M.

AU - Barry, N.

AU - Beardsley, A.P.

AU - Bernardi, G.

AU - Bowman, J.D.

AU - Briggs, F.

AU - Cappallo, R.J.

AU - Carroll, P.

AU - Corey, B.E.

AU - De Oliveira-Costa, A.

AU - Emrich, D.

AU - Feng, L.

AU - Gaensler, B.M.

AU - Goeke, R.

AU - Greenhill, L.J.

AU - Hazelton, B.J.

AU - Hurley-Walker, N.

AU - Johnston-Hollitt, M.

AU - Jacobs, D.C.

AU - Kaplan, D.L.

AU - Kasper, J.C.

AU - Kim, H.S.

AU - Kratzenberg, E.

AU - Lenc, E.

AU - Line, J.

AU - Lonsdale, C.J.

AU - Lynch, M.J.

AU - Mckinley, B.

AU - Mcwhirter, S.R.

AU - Mitchell, D.A.

AU - Morales, M.F.

AU - Morgan, E.

AU - Thyagarajan, N.

AU - Oberoi, D.

AU - Ord, S.M.

AU - Paul, S.

AU - Pindor, B.

AU - Pober, J.C.

AU - Prabu, T.

AU - Procopio, P.

AU - Riding, J.

AU - Rogers, A.E.E.

AU - Roshi, A.

AU - Udaya Shankar, N.

AU - Sethi, S.K.

AU - Srivani, K.S.

AU - Subrahmanyan, R.

AU - Sullivan, I.S.

AU - Tingay, S.J.

AU - Trott, C.M.

AU - Waterson, M.

AU - Wayth, R.B.

AU - Webster, R.L.

AU - Whitney, A.R.

AU - Williams, A.

AU - Williams, C.L.

AU - Wu, Chen

AU - Wyithe, J.S.B.

PY - 2016

Y1 - 2016

N2 - © 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. We present first results from radio observations with the Murchison Widefield Array seeking to constrain the power spectrum of 21 cm brightness temperature fluctuations between the redshifts of 11.6 and 17.9 (113 and 75 MHz). 3 h of observations were conducted over two nights with significantly different levels of ionospheric activity. We use these data to assess the impact of systematic errors at low frequency, including the ionosphere and radio-frequency interference, on a power spectrum measurement. We find that after the 1-3 h of integration presented here, our measurements at the Murchison Radio Observatory are not limited by RFI, even within the FMband, and that the ionosphere does not appear to affect the level of power in the modes that we expect to be sensitive to cosmology. Power spectrum detections, inconsistent with noise, due to fine spectral structure imprinted on the foregrounds by reflections in the signal-chain, occupy the spatial Fourier modes where we would otherwise be most sensitive to the cosmological signal. We are able to reduce this contamination using calibration solutions derived from autocorrelations so that we achieve an sensitivity of 104 mK on comoving scales k?0.5 h Mpc-1. This represents the first upper limits on the 21 cmpower spectrum fluctuations at redshifts 12 ? z ? 18 but is still limited by calibration systematics. While calibration improvements may allow us to further remove this contamination, our results emphasize that future experiments should consider carefully the existence of and their ability to calibrate out any spectral structure within the EoR window.

AB - © 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. We present first results from radio observations with the Murchison Widefield Array seeking to constrain the power spectrum of 21 cm brightness temperature fluctuations between the redshifts of 11.6 and 17.9 (113 and 75 MHz). 3 h of observations were conducted over two nights with significantly different levels of ionospheric activity. We use these data to assess the impact of systematic errors at low frequency, including the ionosphere and radio-frequency interference, on a power spectrum measurement. We find that after the 1-3 h of integration presented here, our measurements at the Murchison Radio Observatory are not limited by RFI, even within the FMband, and that the ionosphere does not appear to affect the level of power in the modes that we expect to be sensitive to cosmology. Power spectrum detections, inconsistent with noise, due to fine spectral structure imprinted on the foregrounds by reflections in the signal-chain, occupy the spatial Fourier modes where we would otherwise be most sensitive to the cosmological signal. We are able to reduce this contamination using calibration solutions derived from autocorrelations so that we achieve an sensitivity of 104 mK on comoving scales k?0.5 h Mpc-1. This represents the first upper limits on the 21 cmpower spectrum fluctuations at redshifts 12 ? z ? 18 but is still limited by calibration systematics. While calibration improvements may allow us to further remove this contamination, our results emphasize that future experiments should consider carefully the existence of and their ability to calibrate out any spectral structure within the EoR window.

U2 - 10.1093/mnras/stw1022

DO - 10.1093/mnras/stw1022

M3 - Article

VL - 460

SP - 4320

EP - 4347

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -