Oral Presentation

Field Variance in LAE-IGM HI Correlation at Cosmic Noon Mapped by Subaru/HSC

Author(s): Yongming Liang (SOKENDAI/NAOJ) et al.

Presenter: Yongming Liang (SOKENDAI/NAOJ)

The correlation between HI in the intergalactic medium (IGM) and galaxies now attracts great interest. We have found a positive and moderate LAE-IGM HI correlation based on a 5.4 deg^2 narrowband survey targeting IGM HI overdense regions suggested by grouping IGM HI absorbers (Liang et al. 2021). Compared with simulations, this relation provides us with an instructive probe to unveil the mechanisms that play dominant roles in pristine HI gas assembly and galaxy formation. However, lines-of-sight from a specific field enclosing the clustering quasars within (40 cMpc)^3 are found to significantly alter this relation's trend, which addresses the importance of a larger sample for discussing possible field variance. Therefore, we include the latest z=2.2 LAE catalog surveyed over the areas of 20 deg^2 from the Subaru HSC-SSP into the correlation analysis. With the HSC-SSP sample, whose size is as large as four times that in our previous study, we find the slope of the relation is flatter in general fields. This confirms the dependence of the variance in LAE-IGM HI correlation on large-scale HI environment.