Reionization in the Light of Dark Stars

Abstract

We investigate the effect of Dark Stars (DSs) on the reionization history of the Universe, and the interplay between them and feedback due to Lyman-Werner (LW) radiation in reducing the Cosmic Microwave Background (CMB) optical depth to a value within the $\tau =0.054\pm 0.007$ range measured by Planck. We use a semi-analytic approach to evaluate reionization histories and CMB optical depths, which includes Population II (Pop II) stars in atomic cooling halos and Pop III stars in minihalos with LW feedback, preceded by a DS phase. We show that while LW feedback by itself can reduce the integrated optical depth to the last scattering surface to $\sim 0.05$ only if the Pop III star formation efficiency is less than $\sim 0.2\%$, the inclusion of a population of DSs can naturally lead to the measured CMB optical depth for much larger Pop III star formation efficiencies $\gtrsim 1\%$.

11 pages, 5 figures

References in corpus (13)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Dark matter and the first stars: a new phase of stellar evolution
• Population III star formation in a Lambda CDM universe, II: Effects of a photodissociating background
• Suppression of H_2 Cooling in the Ultraviolet Background
• A Luminosity Function of Lyman Alpha Emitting Galaxies at Redshift 4.5
• Cradles of the first stars: self-shielding, halo masses, and multiplicity
• The critical dark matter halo mass for Population III star formation: dependence on Lyman-Werner radiation, baryon-dark matter streaming velocity, and redshift
• Supersonic Relative Velocity between Dark Matter and Baryons: A Review
• Probing the star formation history using the redshift evolution of luminosity functions
• Dark stars: Implications and constraints from cosmic reionization and extragalactic background radiation
• Dark Stars: Improved Models and First Pulsation Results
• Cosmic Reionization May Still Have Started Early and Ended Late: Confronting Early Onset with CMB Anisotropy and 21 cm Global Signals
• Stability and pulsation of the first dark stars

Cited by in corpus (4)

• Detectability of Supermassive Dark Stars with the Roman Space Telescope
• Can Dark Stars account for the star formation efficiency excess at very high redshifts?
• Supermassive Dark Stars and their remnants as a possible solution to three recent cosmic dawn puzzles
• Dark-Matter-Powered Population III Evolution: Lifetimes, Rotation, and Quasi-Homogeneity in massive Stars