Speaker
Description
In this work, we focused on the conditions at the Cosmic Dawn, before cosmic reionisation. We place new constraints on the fraction of the neutral hydrogen of the intergalactic medium at z = 9.02-14.18, after analysing Lyman-alpha emission (including upper limits) from 94 galaxy sources. Of these sources, there were 91 3σ upper limits and 3 detections. This analysis was done using JWST data for both PRISM and grating measurements, and incorporated both spectrometric and photometric measurements. New spectra from sources such as JADES Goods-North are included, while one anomalous detection from JADES Goods-South was excluded since it exhibited an abnormally high equivalent width (EW). We updated the IGM neutral fraction (x_HI) to be 0.889 (+0.073 / -0.084). Furthermore, from our model, we found a significant distinction between xHI when variable ionised bubble size was considered versus a fixed bubble size.
