Abstract
Abstract Within standard ΛCDM cosmology, Population III star formation in minihalos of mass M halo ≳ 5 × 105 M ⊙ provides the first stellar sources of Lyα photons. The Experiment to Detect the Global Epoch of Reionization Signature (EDGES) has measured a strong absorption signal of the redshifted 21 cm radiation from neutral hydrogen at z ≈ 17, requiring efficient formation of massive stars before then. In this Letter, we investigate whether star formation in minihalos plays a significant role in establishing the early Lyα background required to produce the EDGES absorption feature. We find that Population III stars are important in providing the necessary Lyα-flux at high redshifts, and derive a best-fitting average Population III stellar mass of ∼750 M ⊙ per minihalo, corresponding to a star formation efficiency of 0.1%. Furthermore, it is important to include baryon-dark matter streaming velocities in the calculation, to limit the efficiency of Population III star formation in minihalos. Without this effect, the cosmic dawn coupling between 21 cm spin temperature and that of the gas would occur at redshifts higher than what is implied by EDGES.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
