English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We examine the evolution of the phase diagram of the low-densityintergalactic medium (IGM) during the Epoch of Reionization in simulation boxeswith varying reionization histories from the Cosmic Reionization on Computersproject. The PDF of gas temperature at fixed density exhibits two clear modes:a warm and cold temperature mode, corresponding to the gas inside and outsideof ionized bubbles. We find that the transition between the two modes is"universal" in the sense that its timing is accurately parameterized by thevalue of the volume-weighted neutral fraction for any reionization history.This "universality" is more complex than just a reflection of the fact thationized gas is warm and neutral gas is cold: it holds for the transition at afixed value of gas density, and gas at different densities transitions from thecold to the warm mode at different values of the neutral fraction, reflecting anon-trivial relationship between the ionization history, the evolving gasdensity PDF, and the spectrum of ionizing radiation. Furthermore, the"emergence" of the tight temperature-density relation in the warm mode is alsoapproximately "universally" controlled by the volume-weighted neutral fractionfor any reionization history. In particular, the "emergence" of thetemperature-density relation (as quantified by the rapid decrease in its width)occurs when the neutral fraction is $10^{-4}\lesssim X_\mathrm{HI}\lesssim10^{-3}$ for any reionization history. Our results indicate that theneutral fraction is a primary quantity controlling the various properties ofthe temperature-density relation, regardless of reionization history.

Emergence of the Temperature-Density Relation in the Low Density Intergalactic Medium