The First Billion Years in Seconds: An Effective Model for the 21-cm Signal with Population III Stars

Abstract

Observations of the 21-cm signal are opening a window to the cosmic-dawn epoch, when the first stars formed. These observations are usually interpreted with semi-numerical or hydrodynamical simulations, which are often computationally intensive and inflexible to changes in cosmological or astrophysical effects. Here, we present an effective, fully analytic model for the impact of the first stars on the 21-cm signal, using the modular code Zeus21. Zeus21 employs an analytic prescription of the star formation rate density (SFRD) to recover the fully nonlinear and nonlocal correlations of radiative fields that determine the 21-cm signal. We introduce the earliest Population III (Pop III) stars residing in low-mass molecular-cooling galaxies in Zeus21, with distinct spectra from later Pop II stars. We also self-consistently model feedback in the form of $H_2$-dissociating Lyman-Werner (LW) radiation, as well as dark matter-baryon relative velocities, both of which suppress star formation in the lowest-mass halos. LW feedback produces a scale-dependence on the SFRD fluctuations, due to the long mean free path of LW photons. Relative velocities give rise to "wiggles" in the spatial distribution of the 21-cm signal; we present an improved calculation of the shape of these velocity-induced acoustic oscillations, showing they remain a standard ruler at cosmic dawn. Our improved version of Zeus21 predicts the 21-cm global signal and power spectra in agreement with simulations at the $\sim 10\%$ level, yet is at least three orders of magnitude faster. This public code represents a step towards efficient and flexible parameter inference at cosmic dawn, allowing us to predict the first billion years of the universe in mere seconds.

37 pages, 17 figures, accepted by PRD

References in corpus (73)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Transients from Initial Conditions in Cosmological Simulations
• Efficient Simulations of Early Structure Formation and Reionization
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• The Global 21 Centimeter Background from High Redshifts
• 21 cm fluctuations from inhomogeneous X-ray heating before reionization
• Resolving the Formation of Protogalaxies. III. Feedback from the First Stars
• Natural Downsizing in Hierarchical Galaxy Formation
• 21CMMC: an MCMC analysis tool enabling astrophysical parameter studies of the cosmic 21 cm signal
• Population III star formation in a Lambda CDM universe, I: The effect of formation redshift and environment on protostellar accretion rate
• Introducing the THESAN project: radiation-magnetohydrodynamic simulations of the epoch of reionization
• Population III star formation in a Lambda CDM universe, II: Effects of a photodissociating background
• The brightest galaxies at Cosmic Dawn
• Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
• Cosmic Reionization On Computers I. Design and Calibration of Simulations
• Suppression of H_2 Cooling in the Ultraviolet Background
• First Season MWA EoR Power Spectrum Results at Redshift 7
• Essential physics of early galaxy formation
• The Fast Fourier Transform Telescope
• The Global 21-cm Signal in the Context of the High-z Galaxy Luminosity Function
• 21cmFAST v3: A Python-integrated C code forgenerating 3D realizations of the cosmic 21cm signal
• The Impact of the First Galaxies on Cosmic Dawn and Reionization
• Reionization and galaxy inference from the high-redshift Lyα forest
• Probing Reionization with the 21 cm-Galaxy Cross Power Spectrum
• Large-scale BAO signatures of the smallest galaxies
• 21 cm signal from cosmic dawn: Imprints of spin temperature fluctuations and peculiar velocities
• 21-cm Background Anisotropies Can Discern Primordial Non-Gaussianity
• Cosmic Reionization and the 21-cm signal: Comparison between an analytical model and a simulation
• Fast Large-Scale Reionization Simulations
• Decoding the X-ray Properties of Pre-Reionization Era Sources
• Was Star-Formation Suppressed in High-Redshift Minihalos?
• When did Population III star formation end?
• The influence of streaming velocities and Lyman-Werner radiation on the formation of the first stars
• Probing Cosmic Dawn with Emission Lines: Predicting Infrared and Nebular Line Emission for ALMA and JWST
• Cradles of the first stars: self-shielding, halo masses, and multiplicity
• Star Formation in the First Galaxies I: Collapse Delayed by Lyman-Werner Radiation
• The Birth Mass Function of Pop III Stars
• Reionization after JWST: a photon budget crisis?
• The critical dark matter halo mass for Population III star formation: dependence on Lyman-Werner radiation, baryon-dark matter streaming velocity, and redshift
• A new MWA limit on the 21 cm Power Spectrum at Redshifts $\sim$ 13 $-$ 17
• Exploring reionisation and high-z galaxy observables with recent multi-redshift MWA upper limits on the 21-cm signal
• Breaking degeneracies in the first galaxies with clustering
• Heating and cooling of the intergalactic medium by resonance photons
• Heating the IGM by X-rays from Population III Binaries in High Redshift Galaxies
• New Roads to the Small-Scale Universe: Measurements of the Clustering of Matter with the High-Redshift UV Galaxy Luminosity Function
• HYREC-2: a highly accurate sub-millisecond recombination code
• An Effective Model for the Cosmic-Dawn 21-cm Signal
• Non-linear Redshift-Space Power Spectra
• A halo model approach for the 21-cm power spectrum at cosmic dawn
• A tale of two sites -- II: Inferring the properties of minihalo-hosted galaxies with upcoming 21-cm interferometers
• Impact of the Primordial Stellar Initial Mass Function on the 21-cm Signal
• Closing the window on fuzzy dark matter with the 21cm signal
• Beware of commonly used approximations I: errors in forecasts
• Characterization of Population III Stars with Stellar Atmosphere and Evolutionary Modeling and Predictions of their Observability with the James Webb Space Telescope
• Beware of commonly used approximations II: estimating systematic biases in the best-fit parameters
• Lyman-Werner Escape Fractions from the First Galaxies
• Redshift-space distortions in simulations of the 21-cm signal from the cosmic dawn
• Low-mass suppression of the satellite luminosity function due to the supersonic baryon--cold-dark-matter relative velocity
• First Constraints on Small-Scale Non-Gaussianity from UV Galaxy Luminosity Functions
• Tracing Pop III supernovae with extreme energies through the Sculptor dwarf spheroidal galaxy
• The importance of galaxy formation histories in models of reionization
• Prospects for distinguishing galaxy evolution models with surveys at redshifts $z\gtrsim 4$
• 21cmfish: Fisher-matrix framework for fast parameter forecasts from the cosmic 21-cm signal
• Probing Population III Initial Mass Functions with He II/H$\alpha$ Intensity Mapping
• An Effective Bias Expansion for 21 cm Cosmology in Redshift Space
• Ionizing photon production of Population III stars: effects of rotation, convection, and initial mass function
• 21cmFirstCLASS I. Cosmological tool for $\Lambda$CDM and beyond
• Measuring the cosmic expansion rate using 21-cm velocity acoustic oscillations
• On the general nature of 21cm-Lyman-$\alpha$ emitters cross-correlations during reionisation
• Probing the intergalactic medium during the Epoch of Reionization using 21-cm signal power spectra
• Studying the Multi-frequency Angular Power Spectrum of the Cosmic Dawn 21-cm Signal
• Spectral Signatures of Population III and Envelope-stripped Stars in Galaxies at the Epoch of Reionization
• The Impact of ionization Morphology and X-ray Heating on the Cosmological 21cm Skew Spectrum

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• oLIMpus: An Effective Model for Line Intensity Mapping Auto- and Cross- Power Spectra in Cosmic Dawn and Reionization
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