The effect of peculiar velocities on the epoch of reionization (EoR) 21-cm signal

Abstract

We have used semi-numerical simulations of reionization to study the behaviour of the power spectrum of the EoR 21-cm signal in redshift space. We have considered two models of reionization, one which has homogeneous recombination (HR) and the other incorporating inhomogeneous recombination (IR). We have estimated the observable quantities --- quadrupole and monopole moments of HI power spectrum at redshift space from our simulated data. We find that the magnitude and nature of the ratio between the quadrupole and monopole moments of the power spectrum ($P_2^s/P_0^s$) can be a possible probe for the epoch of reionization. We observe that this ratio becomes negative at large scales for $x_{HI}\le 0.7$ irrespective of the reionization model, which is a direct signature of an inside-out reionization at large scales. It is possible to qualitatively interpret the results of the simulations in terms of the fluctuations in the matter distribution and the fluctuations in the neutral fraction which have power spectra and cross-correlation $P_{\Delta \Delta }(k)$, $P_{xx}(k)$ and $P_{\Delta x}(k)$ respectively. We find that at large scales the fluctuations in matter density and neutral fraction is exactly anti-correlated through all stages of reionization. This provides a simple picture where we are able to qualitatively interpret the behaviour of the redshift space power spectra at large scales with varying $x_{HI}$ entirely in terms of a just two quantities, namely $x_{HI}$ and the ratio $P_{xx}/P_{\Delta \Delta }$. The nature of $P_{\Delta x}$ becomes different for HR and IR scenarios at intermediate and small scales. We further find that it is possible to distinguish between an inside-out and an outside-in reionization scenario from the nature of the ratio $P_2^s/P_0^s$ at intermediate length scales.

11 pages, 6 figures. Accepted for publication in MNRAS. Replaced to match the accepted version. Added one appendix to quantify the possible uncertainties in the estimation of the multipole moments of redshift space power spectrum

References in corpus (25)

• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Observational constraints on Cosmic Reionization
• Efficient Simulations of Early Structure Formation and Reionization
• The morphology of HII regions during reionization
• Four quasars above redshift 6 discovered by the Canada-France High-z Quasar Survey
• Radiative transfer simulations of cosmic reionization I: methodology and initial results
• The CMBR fluctuations from HI perturbations prior to reionization
• Simulating Cosmic Reionization at Large Scales II: the 21-cm Emission Features and Statistical Signals
• Inside-out or Outside-in: The topology of reionization in the photon-starved regime suggested by Lyman-alpha forest data
• On using visibility correlations to probe the HI distribution from the dark ages to the present epoch I: Formalism and the expected signal
• Redshift Space Distortion of the 21cm Background from the Epoch of Reionization I: Methodology Re-examined
• Probing Reionization with the 21 cm-Galaxy Cross Power Spectrum
• Fast Large-Scale Reionization Simulations
• The simulated 21 cm signal during the epoch of reionization : full modeling of the Ly-alpha pumping
• Lyman-alpha radiative transfer during the Epoch of Reionization: contribution to 21-cm signal fluctuations
• Probing reionization with LOFAR using 21-cm redshift space distortions
• Higher Order Contributions to the 21 cm Power Spectrum
• Cosmological HII Bubble Growth During Reionization
• Connecting Reionization to the Local Universe
• Reionization constraints using Principal Component Analysis
• Current models of the observable consequences of cosmic reionization and their detectability
• Implications of WMAP 3 Year Data for the Sources of Reionization
• Will Nonlinear Peculiar Velocity and Inhomogeneous Reionization Spoil 21cm Cosmology from the Epoch of Reionization?
• A Gunn-Peterson test with a QSO at z=6.4
• Physics of Cosmic Reionization

Cited by in corpus (41)

• Quantifying the non-Gaussianity in the EoR 21-cm signal through bispectrum
• 21 cm signal from cosmic dawn: Imprints of spin temperature fluctuations and peculiar velocities
• On the use of semi-numerical simulations in predicting the 21-cm signal from the epoch of reionization
• The rich complexity of 21-cm fluctuations produced by the first stars
• Light cone effect on the reionization 21-cm signal II: Evolution, anisotropies and observational implications
• Statistics of the epoch of reionization (EoR) 21-cm signal -- II. The evolution of the power spectrum error-covariance
• The Impact of Foregrounds on Redshift Space Distortion Measurements With the Highly-Redshifted 21 cm Line
• The effect of non-Gaussianity on error predictions for the Epoch of Reionization (EoR) 21-cm power spectrum
• 21-cm signal from cosmic dawn - II: Imprints of the light-cone effects
• Towards simulating and quantifying the light-cone EoR 21-cm signal
• The visibility based Tapered Gridded Estimator (TGE) for the redshifted 21-cm power spectrum
• Reionization on Large Scales IV: Predictions for the 21 cm signal incorporating the light cone effect
• Statistics of the epoch of reionization 21-cm signal - I. Power spectrum error-covariance
• Redshifted 21-cm Bispectrum I: Impact of the Redshift Space Distortions on the Signal from the Epoch of Reionization
• Redshift-space distortions in simulations of the 21-cm signal from the cosmic dawn
• The wedge bias in reionization 21-cm power spectrum measurements
• Redshifted 21-cm bispectrum II: Impact of the spin temperature fluctuations and redshift space distortions on the signal from the Cosmic Dawn
• Improving constraints on the reionization parameters using 21-cm bispectrum
• Effects of the sources of reionization on 21-cm redshift-space distortions
• The impact of non-Gaussianity on the error covariance for observations of the Epoch of Reionization 21-cm power spectrum
• Prospects for detecting the 326.5 MHz redshifted 21 cm HI signal with the Ooty Radio Telescope (ORT)
• A method to determine the evolution history of the mean neutral Hydrogen fraction
• Studying Cosmic Dawn using redshifted HI 21-cm signal: A brief review
• The Epoch of Reionization 21-cm Bispectrum: The impact of light-cone effects and detectability
• The impact of non-Gaussianity on the Epoch of Reionization parameter forecast using 21-cm power spectrum measurements
• Investigating X-ray sources during the epoch of reionization with the 21 cm signal
• Impact of dark matter models on the EoR 21-cm signal bispectrum
• Probing early universe through redshifted 21-cm signal: Modelling and observational challenges
• Redshifted 21-cm bispectrum: Impact of the source models on the signal and the IGM physics from the Cosmic Dawn
• The monopole and quadrupole moments of the Epoch of Reionization (EoR) 21-cm bispectrum
• Distinguishing reionization models using the largest cluster statistics of the 21-cm maps
• A Full Treatment of Peculiar Velocities on the Reionization Light Cone
• Line of sight anisotropies in the Cosmic Dawn and EoR 21-cm power spectrum
• Modelling the 21 cm Signal From the Epoch of Reionization and Cosmic Dawn
• Measuring the reionization 21 cm fluctuations using clustering wedges
• Impact of astrophysical scatter on the Epoch of Reionization [H I]${}_{21cm}$ bispectrum
• Interpreting the HI 21-cm cosmology maps through Largest Cluster Statistics -- I: Impact of the synthetic SKA1-Low observations
• Probing the Epoch of Reionization using synergies of line intensity mapping
• The Evolving Power Spectrum for the light cone Epoch of Reionization (EoR) 21-cm signal
• Quantifying and mitigating the effect of snapshot interval in light-cone Epoch of Reionization 21-cm simulations
• Power spectrum multipoles and clustering wedges during the Epoch of Reionization