Simulating the z = 3.35 HI 21-cm visibility signal for the Ooty Wide Field Array(OWFA)

Abstract

The upcoming Ooty Wide Field Array (OWFA) will operate at $326.5\mathrm{MHz}$ which corresponds to the redshifted 21-cm signal from neutral hydrogen (HI) at z = 3.35. We present two different prescriptions to simulate this signal and calculate the visibilities expected in radio-interferometric observations with OWFA. In the first method we use an input model for the expected 21-cm power spectrum to directly simulate different random realizations of the brightness temperature fluctuations and calculate the visibilities. This method, which models the HI signal entirely as a diffuse radiation, is completely oblivious to the discrete nature of the astrophysical sources which host the HI. While each discrete source subtends an angle that is much smaller than the angular resolution of OWFA, the velocity structure of the HI inside the individual sources is well within reach of OWFA's frequency resolution and this is expected to have an impact on the observed HI signal. The second prescription is based on cosmological N-body simulations. Here we identify each simulation particle with a source that hosts the HI, and we have the freedom to implement any desired line profile for the HI emission from the individual sources. Implementing a simple model for the line profile, we have generated several random realizations of the complex visibilities. Correlations between the visibilities measured at different baselines and channels provides an unique method to quantify the statistical properties of the \HI signal. We have used this to quantify the results of our simulations, and explore the relation between the expected visibility correlations and the underlying HI power spectrum.

arXiv commentTo appear in the Special Section of the JAA on the Ooty Wide Field Array

References in corpus (38)

• Planck 2013 results. XVI. Cosmological parameters
• Baryonic Features in the Matter Transfer Function
• The HIPASS catalogue: Omega_HI and environmental effects on the HI mass function of galaxies
• Damped Lyman Alpha Systems at z<1.65: The Expanded SDSS HST Sample
• Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy
• Column density distribution and cosmological mass density of neutral gas: Sloan Digital Sky Survey-III Data Release 9
• Late-time cosmology with 21cm intensity mapping experiments
• On the (Non)Evolution of HI Disks over Cosmic Time
• The Arecibo Legacy Fast ALFA Survey: X. The HI Mass Function and Omega_HI From the 40% ALFALFA Survey
• Discovery of Damped Lyman-Alpha Systems at Redshifts Less Than 1.65 and Results on their Incidence and Cosmological Mass Density
• The evolution of Omega(HI) and the epoch of formation of damped Lyman-alpha absorbers
• Evolution of Neutral Gas at High Redshift -- Implications for the Epoch of Galaxy Formation
• The HI content of star-forming galaxies at z = 0.24
• On using visibility correlations to probe the HI distribution from the dark ages to the present epoch I: Formalism and the expected signal
• The Tianlai project: a 21cm cosmology experiment
• Baryonic Acoustic Oscillations in 21cm Emission: A Probe of Dark Energy out to High Redshifts
• Detection of HI in distant galaxies using spectral stacking
• The multi-frequency angular power spectrum of the epoch of reionization 21 cm signal
• A ground-based 21cm Baryon acoustic oscillation survey
• Using HI to probe large scale structures at z ~ 3
• HI Fluctuations at Large Redshifts: I--Visibility correlation
• Neutral atomic hydrogen (HI) gas evolution in field galaxies at z ~ 0.1 and 0.2
• Fluctuations in 21cm Emission After Reionization
• The First Observations of Low Redshift Damped Lyman-alpha Systems with the Cosmic Origins Spectrograph
• Improved foreground removal in GMRT 610 MHz observations towards redshifted 21-cm tomography
• Theoretical and observational constraints on the HI intensity power spectrum
• Modelling the post-reionization neutral Hydrogen (\HI) bias
• GMRT observation towards detecting the Post-reionization 21-cm signal
• Estimation of Cosmological Parameters from HI Observations of Post-reionization Epoch
• Cosmological constraints from 21cm surveys after reionization
• GMRT observation of neutral atomic hydrogen gas in the COSMOS field at $z\sim 0.37$
• HI Fluctuations at Large Redshifts: III - Simulating the Signal Expected at GMRT
• Constraining large scale HI bias using redshifted 21-cm signal from the post-reionization epoch
• HI Fluctuations at Large Redshifts: II - the Signal Expected for GMRT
• Prospects for detecting the 326.5 MHz redshifted 21 cm HI signal with the Ooty Radio Telescope (ORT)
• Detecting neutral hydrogen in emission at redshift z ~ 1
• A High Speed Networked Signal Processing Platform for Multi-element Radio Telescopes
• Fisher matrix predictions for detecting the cosmological 21 cm signal with the Ooty Wide Field Array (OWFA)

Cited by in corpus (7)

• High-redshift post-reionization cosmology with 21cm intensity mapping
• The Ooty Wide Field Array
• Redshift space distortions of the {\rm HI} 21-cm intensity mapping signal due to the internal motions within galaxies
• Simulated foreground predictions for HI at z = 3.35 with the Ooty Wide Field Array: I. Instrument and the foregrounds
• An analytical method to simulate the HI 21-cm visibility signal for intensity mapping experiments
• A Spherical Harmonic Analysis of the Ooty Wide Field Array (OWFA) Visibility Signal
• Constraining warm dark matter power spectrum using the cross-correlation of HI 21 cm signal and the Lyman-$\alpha$ forest