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.

23 pages, 14 figures, accepted for publication in ApJ

References in corpus (3)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Observational constraints on Cosmic Reionization
• Comparison of observing modes for statistical estimation of the 21cm signal from the Epoch of Reionisation

Cited by in corpus (6)

• Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole
• 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