Impact of astrophysical scatter on the Epoch of Reionization [H I]${}_{21cm}$ bispectrum

Abstract

It is believed that the first star-forming galaxies are the main drivers of cosmic reionization. It is usually assumed that there is a one-to-one relationship between the star formation rate (SFR) inside a galaxy and the host halo mass in semi-analytical/numerical modeling of large-scale reionization. However, more accurate simulations and observations suggest that the SFR and ionizing luminosity in galaxies may vary considerably even if the host halo mass is the same. This astrophysical scatter can introduce an additional non-Gaussianity in the HI 21-cm signal, which the power spectrum might not capture adequately. In this work, we have studied the impact of the scatter on the HI 21-cm bispectrum using semi-numerical simulations. Although the fractional change in the HI 21-cm bispectra due to the scatter is found to be more than a factor of $10$ at large scales ($k_1\lesssim 1{\mathrm{Mpc}}^{-1}$) for $z=7.4$, it is found to be statistically insignificant. However, at small scales ($k_1\sim 2.55$~Mpc${}^{-1}$), we have found the impact due to the scatter to be high in magnitude ($|⟨\Delta B⟩/B_{\text{no-scatter}}|\sim 1$) and statistically significant ($|⟨\Delta B⟩/{\sigma }_{\Delta B}|\gtrsim 5$) at neutral fraction, ${\overline{x}}_{\mathrm{HI}}\sim 0.8$ for $z=7.4$. The impact due to scatter is found to be even more prominent ($|⟨\Delta B⟩/B_{\text{no-scatter}}|\gtrsim 10$) at small scales for $z=10$ and ${\overline{x}}_{\mathrm{HI}}\sim 0.8$, but with reduced statistical significance ($|⟨\Delta B⟩/{\sigma }_{\Delta B}|\sim 3$), compared to $z=7.4$ at the same neutral fraction. In the most optimistic scenario, SKA1-Low might be able to detect these signatures of astrophysical scatter, at $\sim 3\sigma$ and $\sim 5\sigma$ detection significance for ${\overline{x}}_{\mathrm{HI}}\sim$ 0.8 and 0.9 respectively, for the equilateral HI 21-cm bispectrum at $z=7.4$.

26 pages, 12 figures, comments are welcome, accepted in JCAP

References in corpus (33)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Late-time cosmology with 21cm intensity mapping experiments
• 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
• Carbon Monoxide Intensity Mapping at Moderate Redshifts
• Higher Order Contributions to the 21 cm Power Spectrum
• The effect of non-Gaussianity on error predictions for the Epoch of Reionization (EoR) 21-cm power spectrum
• Detection and extraction of signals from the epoch of reionization using higher order one-point statistics
• Multi-tracer intensity mapping: Cross-correlations, Line noise & Decorrelation
• An empirical representation of a physical model for the ISM [CII], CO, and [CI] emission at redshift $1\le z\le 9$
• Quantifying the Redshift Space Distortion of the Bispectrum I: Primordial Non-Gaussianity
• Studying 21cm power spectrum with one-point statistics
• 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
• Precision Tests of CO and [CII] Power Spectra Models against Simulated Intensity Maps
• Redshifted 21-cm bispectrum II: Impact of the spin temperature fluctuations and redshift space distortions on the signal from the Cosmic Dawn
• Studying high-z galaxies with [CII] intensity mapping
• The Epoch of Reionization 21-cm Bispectrum: The impact of light-cone effects and detectability
• Observing the Reionization : Effect of Calibration and Position Errors on Realistic Observation Conditions
• NIHAO XXVI: Nature versus nurture, the Star Formation Main Sequence and the origin of its scatter
• Reionization with Simba: How much does astrophysics matter in modeling cosmic reionization?
• Revisiting the [C II]${}_{158\mu \text{m}}$ line-intensity mapping power spectrum from the EoR using non-uniform line-luminosity scatter
• Lyman-$\alpha$ Polarization Intensity Mapping
• CII and HI 21-cm line intensity mapping from the EoR: Impact of the light-cone effect on auto and cross-power spectra
• Synergizing 21 cm and sub-millimetre surveys during reionization: new empirical insights
• The 21-cm bispectrum from neutral hydrogen islands at z < 6
• The monopole and quadrupole moments of the Epoch of Reionization (EoR) 21-cm bispectrum
• Probing the Epoch of Reionization using synergies of line intensity mapping
• Intensity Mapping with the 21-cm and Lyman Alpha Lines

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