SILVERRUSH. XIV. Lyα Luminosity Functions and Angular Correlation Functions from 20,000 Lyα Emitters at z ∼ 2.2–7.3 from up to 24 deg2 HSC-SSP and CHORUS Surveys: Linking the Postreionization Epoch to the Heart of Reionization
We present luminosity functions (LFs) and angular correlation functions (ACFs) derived from 18,960 Ly α emitters (LAEs) at z = 2.2−7.3 over a wide survey area of ≲24 deg ^2 that are identified in the narrowband data of the HSC-SSP and CHORUS surveys. Confirming the large sample with 241 spectroscop...
Saved in:
| Main Authors: | , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal Supplement Series |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4365/adb1c0 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | We present luminosity functions (LFs) and angular correlation functions (ACFs) derived from 18,960 Ly α emitters (LAEs) at z = 2.2−7.3 over a wide survey area of ≲24 deg ^2 that are identified in the narrowband data of the HSC-SSP and CHORUS surveys. Confirming the large sample with 241 spectroscopically identified LAEs, we determine Ly α LFs and ACFs in the brighter luminosity range down to 0.5 L _⋆ , and confirm that our measurements are consistent with previous studies but offer significantly reduced statistical uncertainties. The improved precision of our ACFs allows us to clearly detect one-halo terms at some redshifts, and provides large-scale bias measurements that indicate host halo masses of ∼10 ^11 M _⊙ over z ≃ 2−7. By comparing our Ly α LF (ACF) measurements with reionization models, we estimate the neutral hydrogen fractions in the intergalactic medium to be x _H _i < 0.05 (= ${0.06}_{-0.03}^{+0.12}$ ) at z = 5.7 and x _H _i = $0.1{5}_{-0.08}^{+0.10}$ ( ${0.21}_{-0.14}^{+0.19}$ ), $0.1{8}_{-0.12}^{+0.14}$ , and $0.7{5}_{-0.13}^{+0.09}$ at z = 6.6, 7.0, and 7.3, respectively. Our findings suggest that the neutral hydrogen fraction remains relatively low, x _H _i ≲ 0.2, at z = 5−7, but increases sharply at z > 7, reaching x _H _i ∼ 0.9 by z ≃ 8−9, as indicated by recent JWST studies. The combination of our results from LAE observations with recent JWST observations suggests that the major epoch of reionization occurred at z ∼ 7−8, likely driven by the emergence of massive sources emitting significant ionizing photons. |
|---|---|
| ISSN: | 0067-0049 |