Implications of the $z>5$ Lyman-$\alpha$ forest for the 21-cm power spectrum from the epoch of reionization

Abstract

Our understanding of the intergalactic medium at redshifts $z=5$-$6$ has improved considerably in the last few years due to the discovery of quasars with $z>6$ that enable Lyman-$\alpha$ forest studies at these redshifts. A realisation from this has been that hydrogen reionization could end much later than previously thought, so that large "islands" of cold, neutral hydrogen could exist in the IGM at redshifts $z=5$-$6$. By using radiative transfer simulations of the IGM, we consider the implications of the presence of these neutral hydrogen islands for the 21-cm power spectrum signal and its potential detection by experiments such as HERA, SKA, LOFAR, and MWA. In contrast with previous models of the 21-cm signal, we find that thanks to the late end of reionization the 21-cm power in our simulation continues to be as high as ${\Delta }_{21}^2=10{\mathrm{mK}}^2$ at $k\sim 0.1h/$cMpc at $z=5$-$6$. This value of the power spectrum is several orders of magnitude higher than that in the conventional models considered in the literature for these redshifts. Such high values of the 21-cm power spectrum should be detectable by HERA and SKA1-LOW in $\sim 1000$ hours, assuming optimistic foreground subtraction. This redshift range is also attractive due to relatively low sky temperature and potentially greater abundance of multiwavelength data.

14 pages, 6 figures, 2 tables. Accepted for publication in MNRAS

References in corpus (31)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Model-independent evidence in favor of an end to reionization by z~6
• Evidence of patchy hydrogen reionization from an extreme Ly$\alpha$ trough below redshift six
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• Keeping the Universe ionised: Photo-heating and the clumping factor of the high-redshift intergalactic medium
• Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
• Feedback-regulated star formation and escape of LyC photons from mini-haloes during reionisation
• A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503
• First Season MWA EoR Power Spectrum Results at Redshift 7
• A radiative transfer scheme for cosmological reionization based on a local Eddington tensor
• The Global 21-cm Signal in the Context of the High-z Galaxy Luminosity Function
• Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
• Reionization and galaxy inference from the high-redshift Lyα forest
• Astraeus I: The interplay between galaxy formation and reionization
• 21 cm signal from cosmic dawn: Imprints of spin temperature fluctuations and peculiar velocities
• Constraining the intergalactic medium at $z\approx$ 9.1 using LOFAR Epoch of Reionization observations
• Self-Consistent Modeling of Reionization in Cosmological Hydrodynamical Simulations
• First Season MWA Phase II EoR Power Spectrum Results at Redshift 7
• The subtlety of Ly-a photons: changing the expected range of the 21-cm signal
• A wide field-of-view low-resolution spectrometer at APEX: instrument design and science forecast
• The Effects of Population III X-ray and Radio Backgrounds on the Cosmological 21-cm Signal
• Studying the Lyman-$\alpha$ optical depth fluctuations at $z\sim 5.5$ using fast semi-numerical methods
• Constraining the state of the intergalactic medium during the Epoch of Reionization using MWA 21-cm signal observations
• Modelling the observed luminosity function and clustering evolution of Lyman-$\alpha$ emitters: growing evidence for late reionization
• Lyman-$\alpha$ coupling and heating at Cosmic Dawn
• The impact of inhomogeneous subgrid clumping on cosmic reionization II: modelling stochasticity
• 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
• Investigating X-ray sources during the epoch of reionization with the 21 cm signal
• The Design of The CCAT-prime Epoch of Reionization Spectrometer Instrument
• SKA LFAA Station Design Report

Cited by in corpus (11)

• Hydrogen reionisation ends by $z=5.3$: Lyman-$\alpha$ optical depth measured by the XQR-30 sample
• Mapper of the IGM spin temperature: instrument overview
• The Predicament of Absorption-Dominated Reionization: Increased Demands on Ionizing Sources
• The 21-cm bispectrum from neutral hydrogen islands at z < 6
• Constraining the 21cm brightness temperature of the IGM at $z$=6.6 around LAEs with the Murchison Widefield Array
• A Multi-messenger view of Cosmic Dawn: Conquering the Final Frontier
• Studying the Multi-frequency Angular Power Spectrum of the Cosmic Dawn 21-cm Signal
• Constraining cosmic reionization by combining the kinetic Sunyaev-Zel'dovich and the 21 cm power spectra
• 21 cm Signal from the Thermal Evolution of Lyman-$\alpha$ during Cosmic Dawn
• Thermal Evolution of the IGM due to Lyman-α photons during the Cosmic Dawn
• Cosmic backgrounds from the radio to the far-infrared: recent results and perspectives from cosmological and astrophysical surveys