Zusammenfassung
We probe what constraints for the global ionized hydrogen fraction the Void
Probability Function (VPF) clustering can give for the Lyman-Alpha Galaxies in
the Epoch of Reionization (LAGER) narrowband survey as a function of area.
Neutral hydrogen acts like a fog for Lyman-alpha emission, and measuring the
drop in the luminosity function of Lyman-$\alpha$ emitters (LAEs) has been used
to constrain the ionization fraction in narrowband surveys. However, the
clustering of LAEs is independent from the luminosity function's inherent
evolution, and can offer additional constraints for reionization under
different models. The VPF measures how likely a given circle is to be empty. It
is a volume-averaged clustering statistic that traces the behavior of higher
order correlations, and its simplicity offers helpful frameworks for planning
surveys.
Using the Jensen2014 simulations of LAEs within various amount of
ionized intergalactic medium, we predict the behavior of the VPF in one
(301x150.5x30 Mpc$^3$), four (5.44$10^6$ Mpc$^3$), or eight (1.1$\times
10^7$ Mpc$^3$) fields of LAGER imaging. We examine the VPF at 5 and 13
arcminutes, corresponding to the minimum scale implied by the LAE density and
the separation of the 2D VPF from random, and the maximum scale from the
8-field 15.5 deg$^2$ LAGER area. We find that even a single DECam field of
LAGER (2-3 deg$^2$) could discriminate between mostly neutral vs. ionized.
Additionally, we find four fields allows the distinction between 30, 50, and 95
percent ionized; and that eight fields could even distinguish between 30, 50,
73, and 95 percent ionized.
Nutzer