### Abstract

Detection of the cosmological neutral hydrogen signal from the Epoch of Reionization (EoR) and estimation of its basic physical parameters are principal scientific aims of many current low-frequency radio telescopes. Here we describe the Cosmological H i Power Spectrum Estimator (CHIPS), an algorithm developed and implemented with data from the Murchison Widefield Array, to compute the two-dimensional and spherically-averaged power spectrum of brightness temperature fluctuations. The principal motivations for CHIPS are the application of realistic instrumental and foreground models to form the optimal estimator, thereby maximizing the likelihood of unbiased signal estimation, and allowing a full covariant understanding of the outputs. CHIPS employs an inverse-covariance weighting of the data through the maximum likelihood estimator, thereby allowing use of the full parameter space for signal estimation ("foreground suppression"). We describe the motivation for the algorithm, implementation, application to real and simulated data, and early outputs. Upon application to a set of 3 hr of data, we set a 2σ upper limit on the EoR dimensionless power at Mpc^{-1} of mK^{2} in the redshift range z = [6.2-6.6], consistent with previous estimates.

Original language | English (US) |
---|---|

Article number | 139 |

Journal | Astrophysical Journal |

Volume | 818 |

Issue number | 2 |

DOIs | |

State | Published - Feb 20 2016 |

### Fingerprint

### Keywords

- Astronomical instrumentation
- early universe
- methods and techniques
- methods: statistical
- techniques: interferometric

### ASJC Scopus subject areas

- Space and Planetary Science
- Astronomy and Astrophysics

### Cite this

*Astrophysical Journal*,

*818*(2), [139]. https://doi.org/10.3847/0004-637X/818/2/139

**CHIPS : The COSMOLOGICAL H i POWER SPECTRUM ESTIMATOR.** / Trott, C. M.; Pindor, B.; Procopio, P.; Wayth, R. B.; Mitchell, D. A.; McKinley, B.; Tingay, S. J.; Barry, N.; Beardsley, A. P.; Bernardi, G.; Bowman, Judd; Briggs, F.; Cappallo, R. J.; Carroll, P.; Oliveira-Costa, A. De; Dillon, Joshua S.; Ewall-Wice, A.; Feng, L.; Greenhill, L. J.; Hazelton, B. J.; Hewitt, J. N.; Hurley-Walker, N.; Johnston-Hollitt, M.; Jacobs, Daniel; Kaplan, D. L.; Kim, H. S.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; Morales, M. F.; Morgan, E.; Neben, A. R.; Thyagarajan, Nithyanandan; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Paul, S.; Pober, J. C.; Prabu, T.; Riding, J.; Shankar, N. Udaya; Sethi, Shiv K.; Srivani, K. S.; Subrahmanyan, R.; Sullivan, I. S.; Tegmark, M.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S B.

Research output: Contribution to journal › Article

*Astrophysical Journal*, vol. 818, no. 2, 139. https://doi.org/10.3847/0004-637X/818/2/139

}

TY - JOUR

T1 - CHIPS

T2 - The COSMOLOGICAL H i POWER SPECTRUM ESTIMATOR

AU - Trott, C. M.

AU - Pindor, B.

AU - Procopio, P.

AU - Wayth, R. B.

AU - Mitchell, D. A.

AU - McKinley, B.

AU - Tingay, S. J.

AU - Barry, N.

AU - Beardsley, A. P.

AU - Bernardi, G.

AU - Bowman, Judd

AU - Briggs, F.

AU - Cappallo, R. J.

AU - Carroll, P.

AU - Oliveira-Costa, A. De

AU - Dillon, Joshua S.

AU - Ewall-Wice, A.

AU - Feng, L.

AU - Greenhill, L. J.

AU - Hazelton, B. J.

AU - Hewitt, J. N.

AU - Hurley-Walker, N.

AU - Johnston-Hollitt, M.

AU - Jacobs, Daniel

AU - Kaplan, D. L.

AU - Kim, H. S.

AU - Lenc, E.

AU - Line, J.

AU - Loeb, A.

AU - Lonsdale, C. J.

AU - Morales, M. F.

AU - Morgan, E.

AU - Neben, A. R.

AU - Thyagarajan, Nithyanandan

AU - Oberoi, D.

AU - Offringa, A. R.

AU - Ord, S. M.

AU - Paul, S.

AU - Pober, J. C.

AU - Prabu, T.

AU - Riding, J.

AU - Shankar, N. Udaya

AU - Sethi, Shiv K.

AU - Srivani, K. S.

AU - Subrahmanyan, R.

AU - Sullivan, I. S.

AU - Tegmark, M.

AU - Webster, R. L.

AU - Williams, A.

AU - Williams, C. L.

AU - Wu, C.

AU - Wyithe, J. S B

PY - 2016/2/20

Y1 - 2016/2/20

N2 - Detection of the cosmological neutral hydrogen signal from the Epoch of Reionization (EoR) and estimation of its basic physical parameters are principal scientific aims of many current low-frequency radio telescopes. Here we describe the Cosmological H i Power Spectrum Estimator (CHIPS), an algorithm developed and implemented with data from the Murchison Widefield Array, to compute the two-dimensional and spherically-averaged power spectrum of brightness temperature fluctuations. The principal motivations for CHIPS are the application of realistic instrumental and foreground models to form the optimal estimator, thereby maximizing the likelihood of unbiased signal estimation, and allowing a full covariant understanding of the outputs. CHIPS employs an inverse-covariance weighting of the data through the maximum likelihood estimator, thereby allowing use of the full parameter space for signal estimation ("foreground suppression"). We describe the motivation for the algorithm, implementation, application to real and simulated data, and early outputs. Upon application to a set of 3 hr of data, we set a 2σ upper limit on the EoR dimensionless power at Mpc-1 of mK2 in the redshift range z = [6.2-6.6], consistent with previous estimates.

AB - Detection of the cosmological neutral hydrogen signal from the Epoch of Reionization (EoR) and estimation of its basic physical parameters are principal scientific aims of many current low-frequency radio telescopes. Here we describe the Cosmological H i Power Spectrum Estimator (CHIPS), an algorithm developed and implemented with data from the Murchison Widefield Array, to compute the two-dimensional and spherically-averaged power spectrum of brightness temperature fluctuations. The principal motivations for CHIPS are the application of realistic instrumental and foreground models to form the optimal estimator, thereby maximizing the likelihood of unbiased signal estimation, and allowing a full covariant understanding of the outputs. CHIPS employs an inverse-covariance weighting of the data through the maximum likelihood estimator, thereby allowing use of the full parameter space for signal estimation ("foreground suppression"). We describe the motivation for the algorithm, implementation, application to real and simulated data, and early outputs. Upon application to a set of 3 hr of data, we set a 2σ upper limit on the EoR dimensionless power at Mpc-1 of mK2 in the redshift range z = [6.2-6.6], consistent with previous estimates.

KW - Astronomical instrumentation

KW - early universe

KW - methods and techniques

KW - methods: statistical

KW - techniques: interferometric

UR - http://www.scopus.com/inward/record.url?scp=84960145189&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84960145189&partnerID=8YFLogxK

U2 - 10.3847/0004-637X/818/2/139

DO - 10.3847/0004-637X/818/2/139

M3 - Article

AN - SCOPUS:84960145189

VL - 818

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 139

ER -