The Universe is at Most 88% Neutral at z = 10.6

June 2023 • 2023ApJ...949L..40B

Authors • Bruton, Sean • Lin, Yu-Heng • Scarlata, Claudia • Hayes, Matthew J.

Abstract • Recent observations of GN-z11 with JWST have revealed a Lyα emission line with an equivalent width (EW) of 18 ± 2 Å. At z = 10.6, this galaxy is expected to lie in the heart of reionization. We use a series of inhomogeneous reionization simulations to derive the distribution of the Lyα EW after traveling through the neutral intergalactic medium with varying average neutral gas fraction, x _{H I}. We use these distributions to place an upper limit of x _{H I} < 0.88 at z = 10.6 at 95% confidence level. We compare our upper limit to different reionization history models, which include the recently identified enhancement at the bright end of the luminosity function at z > 8. We find that models in which faint galaxies have a higher escape fraction compared to bright galaxies are favored by the new data.

Links

• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2023ApJ...949L..40B
• PDF https://iopscience.iop.org/article/10.3847/2041-8213/acd5d0/pdf
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2023ApJ...949L..40B
• PREPRINT http://arxiv.org/abs/2303.03419
• ELECTR https://doi.org/10.3847/2041-8213/acd5d0