BibTeX

@article{2311.16238v1,
Author        = {Huanqing Chen and Joshua Speagle and Keir K. Rogers},
Title         = {Learning Reionization History from Quasars with Simulation-Based
  Inference},
Eprint        = {2311.16238v1},
ArchivePrefix = {arXiv},
PrimaryClass  = {astro-ph.CO},
Abstract      = {Understanding the entire history of the ionization state of the intergalactic
medium (IGM) is at the frontier of astrophysics and cosmology. A promising
method to achieve this is by extracting the damping wing signal from the
neutral IGM. As hundreds of redshift $z>6$ quasars are observed, we anticipate
determining the detailed time evolution of the ionization fraction with
unprecedented fidelity. However, traditional approaches to parameter inference
are not sufficiently accurate. We assess the performance of a simulation-based
inference (SBI) method to infer the neutral fraction of the universe from
quasar spectra. The SBI method adeptly exploits the shape information of the
damping wing, enabling precise estimations of the neutral fraction
$\left<x_{\rm HI}\right>_{\rm v}$ and the wing position $w_p$. Importantly, the
SBI framework successfully breaks the degeneracy between these two parameters,
offering unbiased estimates of both. This makes the SBI superior to the
traditional method using a pseudo-likelihood function. We anticipate that SBI
will be essential to determine robustly the ionization history of the Universe
through joint inference from the hundreds of high-$z$ spectra we will observe.},
Year          = {2023},
Month         = {Nov},
Url           = {http://arxiv.org/abs/2311.16238v1},
File          = {2311.16238v1.pdf}
}