SCORCH. II. Radiation-hydrodynamic Simulations of Reionization with Varying Radiation Escape Fractions

• Published in: The Astrophysical Journal
• Main Authors: Doussot, Aristide, Trac, Hy, Cen, Renyue
• Other Authors: Laboratoire de Physique Théorique de l'ENS École Normale Supérieure (LPTENS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: cosmology: theory; dark ages; reionization; first stars; galaxies: high-redshift; large-scale structure of universe; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; South Pole; South pole
• Online Access: https://hal.science/hal-01974887; https://doi.org/10.3847/1538-4357/aaef75

International audience In the Simulations and Constructions of the Reionization of Cosmic Hydrogen project, we present new radiation-hydrodynamic simulations with updated high-redshift galaxy populations and varying radiation escape fractions. The simulations are designed to have fixed Thomson optical depth τ ≈ 0.06, consistent with recent Planck observations, and similar midpoints of reionization 7.5 ≲ z ≲ 8.0, but with different ionization histories. The galaxy luminosity functions and ionizing photon production rates in our model are in good agreement with recent HST observations. Adopting a power-law form for the radiation escape fraction , we simulate the cases for a 8 = 0, 1, and 2 and find a 8 ≲ 2 in order to end reionization in the range of 5.5 ≲ z ≲ 6.5 to be consistent with Lyα forest observations. At fixed τ and as the power-law slope a 8 increases, the reionization process starts earlier but ends later with a longer duration Δz and the decreased redshift asymmetry Az. We find a range of durations 3.9 ≲ Δz ≲ 4.6 that is currently in tension with the upper limit Δz < 2.8 inferred from a recent joint analysis of Planck and South Pole Telescope observations.