Study of Redshifted HI from the Epoch of Reionization with Drift scan

Abstract

The detection of the Epoch of Reionization (EoR) in the redshifted 21-cm line is a challenging task. Here we formulate the detection of the EoR signal using the drift scan strategy. This method potentially has better instrumental stability as compared to the case where a single patch of sky is tracked. We demonstrate that the correlation time between measured visibilities could extend up to 1-2 hr for an interferometer array such as the Murchison Widefield Array (MWA), which has a wide primary beam. We estimate the EoR power based on cross-correlation of visibilities across time and show that the drift scan strategy is capable of the detection of the EoR signal with comparable/better signal-to-noise as compared to the tracking case. We also estimate the visibility correlation for a set of bright point sources and argue that the statistical inhomogeneity of bright point sources might allow their separation from the EoR signal.

arXiv comment23 pages, 14 figures, accepted for publication in ApJ

References in corpus (13)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• LOFAR: The LOw-Frequency ARray
• The Murchison Widefield Array: the Square Kilometre Array Precursor at low radio frequencies
• Observational constraints on Cosmic Reionization
• 21 Centimeter Fluctuations from Cosmic Gas at High Redshifts
• Science with the Murchison Widefield Array
• New Limits on 21cm EoR From PAPER-32 Consistent with an X-Ray Heated IGM at z=7.7
• Toward Epoch of Reionization Measurements with Wide-Field Radio Observations
• Power Spectrum Sensitivity and the Design of Epoch of Reionization Observatories
• The Sensitivity of First Generation Epoch of Reionization Observatories and Their Potential for Differentiating Theoretical Power Spectra
• The EoR Sensitivity of the Murchison Widefield Array
• Comparison of observing modes for statistical estimation of the 21cm signal from the Epoch of Reionisation

Cited by in corpus (9)

• CHIPS: The Cosmological HI Power Spectrum Estimator
• Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole
• Understanding the Diversity of 21 cm Cosmology Analyses
• Visibility based angular power spectrum estimation in low frequency radio interferometric observations
• A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
• Extracting the 21 cm EoR signal using MWA drift scan data
• Delay Spectrum with Phase-Tracking Arrays: Extracting the HI power spectrum from the Epoch of Reionization
• The Tracking Tapered Gridded Estimator (TTGE) for the power spectrum from drift scan observations
• Detecting 21 cm EoR Signal using Drift Scans: Correlation of Time-ordered Visibilities