Spencer Fuller - Academia.edu (original) (raw)
Uploads
Papers by Spencer Fuller
The Astrophysical Journal, 2019
During reionization, the intergalactic medium is heated impulsively by supersonic ionization fron... more During reionization, the intergalactic medium is heated impulsively by supersonic ionization fronts (I-fronts). The peak gas temperatures behind the I-fronts, T reion , are a key uncertainty in models of the thermal history after reionization. Here we use high-resolution radiative transfer simulations to study the parameter space of T reion. We show that T reion is only mildly sensitive to the spectrum of incident radiation over most of the parameter space, with temperatures set primarily by I-front speeds. We also explore what current models of reionization predict for T reion by measuring I-front speeds in cosmological radiative transfer simulations. We find that the post-I-front temperatures evolve toward hotter values as reionization progresses. Temperatures of T reion = 17, 000−22, 000 K are typical during the first half of reionization, but T reion = 25, 000 − 30, 000 K may be achieved near the end of this process if I-front speeds reach ∼ 10 4 km/s as found in our simulations. Shorter reionization epochs lead to hotter T reion. We discuss implications for z > 5 Lyα forest observations, which potentially include sight lines through hot, recently reionized patches of the Universe. Interpolation tables from our parameter space study are made publicly available, along with a simple fit for the dependence of T reion on the I-front speed.
The Astrophysical Journal, 2019
During reionization, the intergalactic medium is heated impulsively by supersonic ionization fron... more During reionization, the intergalactic medium is heated impulsively by supersonic ionization fronts (I-fronts). The peak gas temperatures behind the I-fronts, T reion , are a key uncertainty in models of the thermal history after reionization. Here we use high-resolution radiative transfer simulations to study the parameter space of T reion. We show that T reion is only mildly sensitive to the spectrum of incident radiation over most of the parameter space, with temperatures set primarily by I-front speeds. We also explore what current models of reionization predict for T reion by measuring I-front speeds in cosmological radiative transfer simulations. We find that the post-I-front temperatures evolve toward hotter values as reionization progresses. Temperatures of T reion = 17, 000−22, 000 K are typical during the first half of reionization, but T reion = 25, 000 − 30, 000 K may be achieved near the end of this process if I-front speeds reach ∼ 10 4 km/s as found in our simulations. Shorter reionization epochs lead to hotter T reion. We discuss implications for z > 5 Lyα forest observations, which potentially include sight lines through hot, recently reionized patches of the Universe. Interpolation tables from our parameter space study are made publicly available, along with a simple fit for the dependence of T reion on the I-front speed.