Impact of the Primordial Stellar Initial Mass Function on the 21-cm Signal

Abstract

Properties of the first generation of stars (Pop III), such as their initial mass function (IMF), are poorly constrained by observations and have yet to converge between simulations. The cosmological 21-cm signal of neutral hydrogen is predicted to be sensitive to Lyman-band photons produced by these stars, thus providing a unique way to probe the first stellar population. In this paper, we investigate the impacts of the Pop III IMF on the cosmic dawn 21-cm signal via the Wouthuysen-Field effect, Lyman-Werner feedback, Ly-alpha heating, and CMB heating. We calculate the emission spectra of star-forming halos for different IMFs by integrating over individual metal-free stellar spectra, computed from a set of stellar evolution histories and stellar atmospheres, and taking into account variability of the spectra with stellar age. Through this study, we therefore relax two common assumptions: that the zero-age main sequence emission rate of a Pop III star is representative of its lifetime mean emission rate, and that Pop III emission can be treated as instantaneous. Exploring a bottom-heavy, a top-heavy, and intermediate IMFs, we show that variations in the 21-cm signal are driven by stars lighter than 20 solar masses. For the explored models we find maximum relative differences of 59% in the cosmic dawn global 21-cm signal, and 131% between power spectra. Although this impact is modest, precise modelling of the first stars and their evolution is necessary for accurate prediction and interpretation of the 21-cm signal.

20 pages, 16 figures. Accepted for publication in MNRAS, updated to accepted version

References in corpus (35)

• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Nucleosynthesis and Remnants in Massive Stars of Solar Metallicity
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Mind the gap: The location of the lower edge of the pair instability supernovae black hole mass gap
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• Population III stars: hidden or disappeared ?
• First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
• Signature of Excess Radio Background in the 21-cm Global Signal and Power Spectrum
• Two populations of metal-free stars in the early Universe
• Testing for calibration systematics in the EDGES low-band data using Bayesian model selection
• Simulating cosmic metal enrichment by the first galaxies
• The Impact of the First Galaxies on Cosmic Dawn and Reionization
• Constraining the primordial initial mass function with stellar archaeology
• The REACH radiometer for detecting the 21-cm hydrogen signal from redshift 7.5 to 28
• Limits on Pop III star formation with the most iron-poor stars
• Decoding the stellar fossils of the dusty Milky Way progenitors
• Formation sites of Population III star formation: The effects of different levels of rotation and turbulence on the fragmentation behavior of primordial gas
• Merge or survive: Number of Population III stars per minihalo
• The Effects of Population III X-ray and Radio Backgrounds on the Cosmological 21-cm Signal
• Constraining First Star Formation with 21cm-Cosmology
• Grids of stellar models with rotation: V. Models from 1.7 to 120 Msun at zero metallicity
• Radio background and IGM heating due to Pop III supernovae explosions
• A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
• Observational constraints on the survival of pristine stars
• Implications of inhomogeneous metal mixing for stellar archaeology
• Informing antenna design for sky-averaged 21-cm experiments using a simulated Bayesian data analysis pipeline
• X-ray Background at High Redshifts from Pop III Remnants: Results from Pop III star formation rates in the Renaissance Simulations
• Probing the first galaxies with the SKA
• Constraining Warm Dark Matter and Pop III stars with the Global 21-cm Signal
• Can the 21 cm signal probe Population III and II star formation?
• Shot noise and scatter in the star formation efficiency as a source of 21-cm fluctuations
• Ionizing photon production of Population III stars: effects of rotation, convection, and initial mass function
• Modelling Population III stars for semi-numerical simulations
• Epoch of Reionization Power Spectrum Limits from Murchison Widefield Array Data Targeted at EoR1 Field

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• RIGEL: Simulating dwarf galaxies at solar mass resolution with radiative transfer and feedback from individual massive stars
• Modelling the cosmological Lyman-Werner background radiation field in the Early Universe
• Signatures of Cosmic Ray Heating in 21-cm Observables
• Exploiting synergies between JWST and cosmic 21-cm observations to uncover star formation in the early Universe
• The role of Pop III stars and early black holes in the 21cm signal from Cosmic Dawn
• Gravitational waves from mergers of Population III binary black holes: roles played by two evolution channels
• The most massive Population III stars
• Machine-learning recovery of foreground wedge-removed 21-cm light cones for high-$z$ galaxy mapping
• The First Billion Years in Seconds: An Effective Model for the 21-cm Signal with Population III Stars
• The THESAN-ZOOM project: Population III star formation continues until the end of reionization
• Distinguishing the impact and signature of black holes from different origins in early cosmic history
• Cosmic mysteries and the hydrogen 21-cm line: bridging the gap with lunar observations
• Impact of cosmic rays on the global 21-cm signal during cosmic dawn
• The mass distribution of the first stars can be determined via the 21-cm signal
• Effects of chemically homogeneous evolution of the first stars on the 21-cm signal and reionization
• Understanding spectral artefacts in SKA-LOW 21-cm cosmology experiments: the impact of cable reflections
• Narrowing the discovery space of the cosmological 21-cm signal using multi-wavelength constraints
• Predictions of the 21cm global signal in the JWST and ALMA era
• Ultraviolet photon production rates of the first stars: Impact on the He II $\lambda$ 1640 Å emission line from primordial star clusters and the 21-cm signal from cosmic dawn
• RIGEL: Feedback-regulated cloud-scale star formation efficiency in a simulated dwarf galaxy merger
• Influence of the deviation of the matter power spectrum at small scales on the global 21-cm signal at cosmic dawn
• Calibrating Bayesian Tension Statistics using Neural Ratio Estimation
• Optimizing Foreground Modelling for Global 21cm Cosmology with GPU-Accelerated Nested Sampling