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Title: 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 τ = 0.054 ± 0.007 range measured by Planck. We use a semianalytic approach to evaluate reionization histories and CMB optical depths, which includes Population II stars in atomic cooling halos and Population 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 ∼0.05 only if the Population III star formation efficiency is less than ∼0.2%, the inclusion of a population of DSs can naturally lead to the measured CMB optical depth for much larger Population III star formation efficiencies ≳1%.  more » « less
Award ID(s):
2014075 2009309
PAR ID:
10387265
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
935
Issue:
1
ISSN:
0004-637X
Page Range / eLocation ID:
11
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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