TY - JOUR
T1 - Statistical correlation between the distribution of Lyα emitters and intergalactic medium HI at z ∼ 2.2 mapped by the subaru/hyper suprime-cam
AU - Liang, Yongming
AU - Kashikawa, Nobunari
AU - Cai, Zheng
AU - Fan, Xiaohui
AU - Xavier Prochaska, J.
AU - Shimasaku, Kazuhiro
AU - Tanaka, Masayuki
AU - Uchiyama, Hisakazu
AU - Ito, Kei
AU - Shimakawa, Rhythm
AU - Nagamine, Kentaro
AU - Shimizu, Ikkoh
AU - Onoue, Masafusa
AU - Toshikawa, Jun
N1 - Funding Information:
This work was supported in part by the Graduate University for Advanced Studies, SOKENDAI. This work is based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. This paper makes use of software developed for the Large Synoptic Survey Telescope. We thank the LSST Project for making their code available as free software athttp://dm.lsst.org.
Funding Information:
Numerical simulations were carried out on the Cray XC50 at the Center for Computational Astrophysics, National Astronomical Observatory of Japan, and the OCTOPUS at the Cybermedia Center, Osaka University as part of the HPCI system Research Project (hp180063, hp190050). This work is supported in part by JSPS KAKENHI grant No. JP17H01111, 19H05810 (K.N.). K.N. acknowledges the travel support from the Kavli IPMU, World Premier Research Center Initiative (WPI), where part of this work was conducted.
Publisher Copyright:
© 2021. The American Astronomical Society. All rights reserved.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/1/20
Y1 - 2021/1/20
N2 - The correlation between neutral hydrogen (H I) in the intergalactic medium (IGM) and galaxies attracts great interest. We select four fields that include several coherently strong Lyα absorption systems at z ∼ 2.2 detected using background quasars from the whole SDSS/(e) Baryon Oscillation Spectroscopic Survey (BOSS) database. Deep narrowband and g-band imaging are performed using the Hyper Suprime-Cam on the Subaru Telescope. We select 2642 Lyα emitter (LAE) candidates at z = 2.177 ± 0.023 down to the Lyα luminosity of LLyα ≈ 2 × 1042 erg s−1 to construct the galaxy overdensity maps, covering an effective area of 5.39 deg2. Combining the sample with the Lyα absorption estimated from 64 (e) BOSS quasar spectra, we find a moderate to strong correlation between the LAE overdensity δLAE and the effective optical depth τLoS in lines of sight, with P value = 0.09% or <0.01% when the field containing a significant quasar overdensity is included or excluded. Cross-correlation analysis also clearly suggests that up to 4 ± 1 pMpc, LAEs tend to cluster in regions rich in H I gas, as indicated by the high τLoS, and avoid the low τLoS regions where the H I gas is deficient. By averaging the τLoS as a function of the projected distance (d) to LAEs, we find a 30% excess signal at 2σ level at d < 200 pkpc, indicating the dense H I in the circumgalactic medium, and a tentative excess at 400 < d < 600 pkpc in the IGM regime, corroborating the cross-correlation signal detected at about 0.5 pMpc. These statistical analyses suggest that galaxy−IGM H I correlations exist on scales ranging from several hundred pkpc to several pMpc at z ∼ 2.2.
AB - The correlation between neutral hydrogen (H I) in the intergalactic medium (IGM) and galaxies attracts great interest. We select four fields that include several coherently strong Lyα absorption systems at z ∼ 2.2 detected using background quasars from the whole SDSS/(e) Baryon Oscillation Spectroscopic Survey (BOSS) database. Deep narrowband and g-band imaging are performed using the Hyper Suprime-Cam on the Subaru Telescope. We select 2642 Lyα emitter (LAE) candidates at z = 2.177 ± 0.023 down to the Lyα luminosity of LLyα ≈ 2 × 1042 erg s−1 to construct the galaxy overdensity maps, covering an effective area of 5.39 deg2. Combining the sample with the Lyα absorption estimated from 64 (e) BOSS quasar spectra, we find a moderate to strong correlation between the LAE overdensity δLAE and the effective optical depth τLoS in lines of sight, with P value = 0.09% or <0.01% when the field containing a significant quasar overdensity is included or excluded. Cross-correlation analysis also clearly suggests that up to 4 ± 1 pMpc, LAEs tend to cluster in regions rich in H I gas, as indicated by the high τLoS, and avoid the low τLoS regions where the H I gas is deficient. By averaging the τLoS as a function of the projected distance (d) to LAEs, we find a 30% excess signal at 2σ level at d < 200 pkpc, indicating the dense H I in the circumgalactic medium, and a tentative excess at 400 < d < 600 pkpc in the IGM regime, corroborating the cross-correlation signal detected at about 0.5 pMpc. These statistical analyses suggest that galaxy−IGM H I correlations exist on scales ranging from several hundred pkpc to several pMpc at z ∼ 2.2.
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U2 - 10.3847/1538-4357/abcd93
DO - 10.3847/1538-4357/abcd93
M3 - Article
AN - SCOPUS:85100978316
VL - 907
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 3
ER -