Early reionization by the first galaxies

By Benedetta Ciardi, A. Ferrara, S. D. M. White. 2003

186 citations recorded by the source corpus.

Large-scale polarization of the cosmic microwave background measured by the WMAP satellite requires a mean optical depth to Thomson scattering, τ e ∼ 0.17. The reionization of the Universe must therefore have begun at relatively high redshift. We have studied the reionization process using supercomputer simulations of a large and representative region of a universe which has cosmological parameters consistent with the WMAP results (Ω m = 0.3, Ω Λ = 0.7, h = 0.7, Ω b = 0.04, n = 1 and σ 8 = 0.9). Our simulations follow both the radiative transfer of ionizing photons and the formation and evolution of the galaxy population which produces them. A previously published model with ionizing photon production as expected for zero-metallicity stars distributed according to a standard stellar initial mass function (IMF) (10 6 1 photons per unit solar mass of formed stars) and with a moderate photon escape fraction from galaxies (5 per cent), produces τ e = 0.104, which is within 1.0 to 1.5σ of the 'best' WMAP value. Values of up to 0.16 can be produced by taking larger escape fractions or a top-heavy IMF. The data do not require a separate populations of 'miniquasars' or of stars forming in objects with total masses below 10 9 M O .. Reconciling such early reionization with the observed Gunn-Peterson troughs in z > 6 quasars may be challenging. Possible resolutions of this problem are discussed.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/7869f37c74395efbea79db269e5a2438fcabbcaf

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Citations in the corpus

Radiative Transfer Simulations of Cosmic Reionization. I. Methodology and Initial Results (2006, background): “Large-volume but low-resolution simulations (e.g., Sokasian et al. 2003; Ciardi et al. 2003; Kohler et al. 2007; Iliev et al. 2006, 2007; Zahn et al. 2007;McQuinn et al. 2007) enable the study of the large-scale structure of dark matter, baryons, sources, and H ii regions, but theymust correct for…”
COSMIC MICROWAVE BACKGROUND CONSTRAINTS ON THE DURATION AND TIMING OF REIONIZATION FROM THE SOUTH POLE TELESCOPE (2011, background): “D radiative transfer codes (e.g., Gnedin 2000; Sokasian et al. 2001; Razoumov et al. 2002; Ciardi et al. 2003; Mellema et al. 2006; McQuinn et al. 2007b; Semelin et al. 2007; Trac & Cen 2007a; Altay et al. 2008; Aubert & Teyssier 2008; Finlator et al. 2009; Petkova & Springel 2009).”
Comparison of reionization models: radiative transfer simulations and approximate, seminumeric models (2010, background): “D radiative transfer (RT) codes (e.g. Gnedin 2000; Razoumov et al. 2002; Ciardi et al. 2003; Sokasian et al. 2001; Mellema et al. 2006; McQuinn et al. 2007b; Semelin et al. 2007; Trac & Cen 2007; Altay et al. 2008; Aubert & Teyssier 2008; Finlator et al. 2009; Petkova & Springel 2009; see the…”
Chemical Evolution in Hierarchical Models of Cosmic Structure. I. Constraints on the Early Stellar Initial Mass Function (2005, background): “This early reionization can be explained by a variety of models, but the most commonly cited explanation is that early star formation is unusually efficient at converting stellar mass into ionizing photons (Cen 2003; Haiman & Holder 2003; Ciardi et al. 2003; TVS04).”
The large-scale structure of the Universe (2006, background): “By a redshift of 15 these may have been sufficiently numerous for their radiation to re-ionize all the gas in the Univers”
ESCAPE FRACTION OF IONIZING PHOTONS DURING REIONIZATION: EFFECTS DUE TO SUPERNOVA FEEDBACK AND RUNAWAY OB STARS (2014, background): “…& Haehnelt 2007; Wyithe & Cen 2007; Kuhlen & Faucher-Giguère 2012; Robertson et al. 2013) and numerically (e.g.Gnedin 2000a; Razoumov et al. 2002; Ciardi et al. 2003; Fujita et al. 2003; Trac & Cen 2007; Gnedin et al. 2008; Wise & Cen 2009; Razoumov & Sommer-Larsen 2010; Yajima et al. 2011;…”
Formation of isolated dwarf galaxies with feedback (2009, background): “Furthermore, while there may be local variations in the UV background, particularly at higher redshift and from sources other than quasars (e.g. Ciardi et al. 2003), the mean free path of UV photons in the intergalactic medium is on the or- der of tens of Mpc (Bolton et al. 2004).”
Simulations and Analytic Calculations of Bubble Growth during Hydrogen Reionization (2006, background): “Detailed theoretical modeling (see e.g. Gnedin 2000; Razoumov et al. 2002; Ciardi et al. 2003; Sokasian et al. 2002; Sokasian et al. 2001; Furlanetto et al. 2004b,a; Kohler et al. 2005; Iliev et al. 2005; Mellema et al. 2006) is, however, required to constrain the topology of reionization from…”
Gaseous Galaxy Halos (2012, background): “Constraints on the escape fraction impact both halo gas and the ionization of the IGM as a whole, in particular at higher redshift (e.g., Ciardi et al., 2003; Gnedin, 2000).”
Cosmic reionization by stellar sources: population III stars (2003, methodology): “…the cases with M > 1.0 × 109 h−1 M and M > 0.3 × 109 h−1 M , which are close to the mass resolution of sources in the ‘M3’ and ‘S3’ simulations described by Ciardi et al. (2003b), appear to account for only 53 per cent and 81 per cent of the total star formation rate, respectively, relative to…”
Galactic Chemical Evolution: Carbon through Zinc (2006, methodology): “The re-ionization of the universe at very early epoch as suggested by the WMAP result may require a different population for the first stars (e.g., Ciardi et al. 2003).”
Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Cosmology (2006, unknown): “Since the Kogut et al. (2003) detection of , the physics of reionization has been a subject of extensive theoretical study (Cen 2003; Ciardi et al. 2003; Haiman & Holder 2003; Madau et al. 2004; Oh & Haiman 2003; Venkatesan et al. 2003; Ricotti & Ostriker 2004; Sokasian et al. 2004; Somerville &…”
Fast large volume simulations of the 21-cm signal from the reionization and pre-reionization epochs (2009, background): “…simulation), plus a full radiative transfer code to propagate the ionizing radiation (Gnedin 2000; Razoumov et al. 2002; Sokasian et al. 2003; Ciardi et al. 2003; Kohler et al. 2005; Iliev et al. 2006; Zahn et al. 2007; McQuinn et al. 2007; Shin et al. 2007; Trac & Cen 2007; Baek et al.…”