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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We investigate the impact of field-to-field variation, deriving from cosmicvariance, in measured Lyman-$\alpha$ emitter (LAE) luminosity functions (LFs)and this variation's impact on inferences of the neutral fraction of theintergalactic medium (IGM) during reionization. We post-process a z=7 IGMsimulation to populate the dark matter halos with LAEs. These LAEs haverealistic UV magnitudes, Ly$\alpha$ fluxes, and Ly$\alpha$ line profiles. Wecalculate the attenuation of Ly$\alpha$ emission in universes with varying IGMneutral fraction, $\bar{\rm{x}}_{\rm{HI}}$. In a $\bar{\rm{x}}_{\rm{HI}}=0.3$simulation, we perform 100 realizations of a mock 2 square degree survey with aredshift window $\Delta z = 0.5$ and flux limit$\rm{f}_{Ly\alpha}>1\times10^{-17}\:\rm{ergs}\:\: \rm{s}^{-1} \: \rm{cm}^{-2}$;such a survey is typical in depth and volume of the largest LAE surveysconducted today. For each realization, we compute the LAE LF and use it torecover the input $\bar{\rm{x}}_{\rm{HI}}$. Comparing the inferred values of$\bar{\rm{x}}_{\rm{HI}}$ across the ensemble of the surveys, we find thatcosmic variance, deriving from large-scale structure and variation in theneutral gas along the sightline, imposes a floor in the uncertainty of $\Delta\bar{\rm{x}}_{\rm{HI}} \sim 0.2$ when $\bar{\rm{x}}_{\rm{HI}}$ $=0.3$. Weexplore mitigation strategies to decrease this uncertainty, such as increasingthe volume, decreasing the flux limit, or probing the volume with manyindependent fields. Increasing the area and/or depth of the survey does notmitigate the uncertainty, but composing a survey with many independent fieldsis effective. This finding highlights the best strategy for LAE surveys aimingat constraining $\bar{\rm{x}}_{\rm{HI}}$ of the universe during reionization.

The Impact of Cosmic Variance on Inferences of Global Neutral Fraction Derived from Ly$\alpha$ Luminosity Functions During Reionization