Systematic Identification of LAEs for Visible Exploration and Reionization Research Using Subaru HSC (SILVERRUSH). I. Program strategy and clustering properties of ̃2000 Lyα emitters at z = 67 over the 0.30.5 Gpc^{2} survey area
Abstract
We present the SILVERRUSH program strategy and clustering properties investigated with ̃2000 Lyα emitters (LAEs) at z = 5.7 and 6.6 found in the early data of the Hyper SuprimeCam (HSC) Subaru Strategic Program survey exploiting the carefully designed narrowband filters. We derive angular correlation functions with the unprecedentedly large samples of LAEs at z = 67 over the large total area of 1421 deg^{2} corresponding to 0.30.5 comoving Gpc^{2}. We obtain the average largescale bias values of b_{avg} = 4.1 ± 0.2 (4.5 ± 0.6) at z = 5.7 (z = 6.6) for ≳ L* LAEs, indicating a weak evolution of LAE clustering from z = 5.7 to 6.6. We compare the LAE clustering results with two independent theoretical models that suggest an increase of an LAE clustering signal by the patchy ionized bubbles at the epoch of reionization (EoR), and estimate the neutral hydrogen fraction to be x_{H I}=0.15^{+0.15}_{0.15} at z = 6.6. Based on the halo occupation distribution models, we find that the ≳ L* LAEs are hosted by darkmatter halos with an average mass of log (< M_h > /M_☉ ) =11.1^{+0.2}_{0.4} (10.8^{+0.3}_{0.5}) at z = 5.7 (6.6) with a Lyα duty cycle of 1% or less, where the results of z = 6.6 LAEs may be slightly biased, due to the increase of the clustering signal at the EoR. Our clustering analysis reveals the lowmass nature of ≳ L* LAEs at z = 67, and that these LAEs probably evolve into massive superL* galaxies in the presentday universe.
 Publication:

Publications of the Astronomical Society of Japan
 Pub Date:
 January 2018
 DOI:
 10.1093/pasj/psx074
 arXiv:
 arXiv:1704.07455
 Bibcode:
 2018PASJ...70S..13O
 Keywords:

 cosmology: observations;
 galaxies: formation;
 galaxies: highredshift;
 Astrophysics  Astrophysics of Galaxies;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 16 pages, 10 figures. Accepted for publication in PASJ special issue