Cosmic Reionization On Computers. Properties of the Post-reionization IGM

TL;DR

This paper compares observational data of the post-reionization intergalactic medium with CROC simulations, highlighting areas of agreement and discrepancy in spectral properties, especially regarding opacity and peak distributions.

Contribution

It provides a detailed comparison between observational tests and high-resolution simulations of the post-reionization IGM, identifying specific mismatches and their potential causes.

Findings

Simulations match the gap distribution reasonably well.

Good match for the distribution of peak heights.

Simulations show more opacity than observed.

Abstract

We present a comparison between several observational tests of the post-reionization IGM and the numerical simulations of reionization completed under the Cosmic Reionization On Computers (CROC) project. The CROC simulations match the gap distribution reasonably well, and also provide a good match for the distribution of peak heights, but there is a notable lack of wide peaks in the simulated spectra and the flux PDFs are poorly matched in the narrow redshift interval 5.5<z<5.7, with the match at other redshifts being significantly better, albeit not exact. Both discrepancies are related: simulations show more opacity than the data.