LBT/LUCI SPECTROSCOPIC OBSERVATIONS of z≃7 Galaxies GALAXIES

Fuyan Bian, Daniel P Stark, Xiaohui Fan, Linhua Jiang, Benjamin Clément, Eiichi Egami, Brenda Louise Frye, Richard F. Green, Ian D. McGreer, Zheng Cai

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We present deep near-infrared spectroscopic observations of 13 luminous z ≃ 7 Lyman break galaxies (LBGs) (MUV ≃ -21) and a z ≃ 9.6 lensed LBG candidate, MACS1149-JD1, using the LBT/LUCI spectrograph in the multi-object mode and long-slit mode, respectively. The z ∼ 7 galaxies are selected in one of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/WIDE survey observations, the UKIRT Infrared Deep Sky Survey Ultra Deep Survey field, and MACS1159-JD1 is selected from the Cluster Lensing And Supernova survey with Hubble survey observations. With ∼ 4-5 hr integrations, the LBT spectra are sensitive to Ly α emission, with rest-frame equivalent width greater than 55 ł (EW0 > 55 ł) at z ≃ 7 and 90 (EW0 > 90 ł) at z ∼ 9.5. No Ly α emission is observed in any of the z ≃ 7 LBGs. After correcting the spectroscopic incompleteness, our measurements place an upper limit on the Ly α emission fraction o XLya (EW0 > 55 ł, z ≃ 7) < 9.8% in luminous LBGs at z ≃ 7. This result is consistent with the lack of Lyα emission in z >7 LBGs in previous studies. Together with other measurements of the Lyα emission fraction in LBGs at z ≃7, this study puts a strong constraint on the fraction of luminous z ≃ 7 LBGs with large EWX<inf>Lyα</inf>, X (EW <inf>0</inf>55 ł, z ≃ 7) 2.6<sup>+ 3.2</sup><inf>-2.6</inf> %. We estimate the expected Lyα emission fraction at z≃7 by extrapolating the evolution of the fraction at low redshifts and find that the observed Lyα emission fraction is lower than the expected Lyα emission fraction at the 89% significance?level, consistent with expectations if Lyα emission in z≃7 LBGs has been suppressed by neutral hydrogen in the intergalactic medium or optically thick absorbers around the galaxies. We do not find any strong Lyα emission feature at the redshift range of z≃7.3-9.7 in the MACSJ1159-JD1 spectrum, either. This is consistent with the conclusion that Lyα emission in the galaxy has been highly suppressed.

Original languageEnglish (US)
Article number108
JournalAstrophysical Journal
Volume806
Issue number1
DOIs
StatePublished - Jun 10 2015

Fingerprint

galaxies
near infrared
intergalactic media
field survey
spectrographs
slits
supernovae
absorbers
assembly
hydrogen
estimates

Keywords

  • cosmology: observations
  • galaxies: evolution
  • galaxies: high-redshift

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

LBT/LUCI SPECTROSCOPIC OBSERVATIONS of z≃7 Galaxies GALAXIES. / Bian, Fuyan; Stark, Daniel P; Fan, Xiaohui; Jiang, Linhua; Clément, Benjamin; Egami, Eiichi; Frye, Brenda Louise; Green, Richard F.; McGreer, Ian D.; Cai, Zheng.

In: Astrophysical Journal, Vol. 806, No. 1, 108, 10.06.2015.

Research output: Contribution to journalArticle

Bian, F, Stark, DP, Fan, X, Jiang, L, Clément, B, Egami, E, Frye, BL, Green, RF, McGreer, ID & Cai, Z 2015, 'LBT/LUCI SPECTROSCOPIC OBSERVATIONS of z≃7 Galaxies GALAXIES', Astrophysical Journal, vol. 806, no. 1, 108. https://doi.org/10.1088/0004-637X/806/1/108
Bian, Fuyan ; Stark, Daniel P ; Fan, Xiaohui ; Jiang, Linhua ; Clément, Benjamin ; Egami, Eiichi ; Frye, Brenda Louise ; Green, Richard F. ; McGreer, Ian D. ; Cai, Zheng. / LBT/LUCI SPECTROSCOPIC OBSERVATIONS of z≃7 Galaxies GALAXIES. In: Astrophysical Journal. 2015 ; Vol. 806, No. 1.
@article{b856c9d7e604425c8ea85fb5085fbe10,
title = "LBT/LUCI SPECTROSCOPIC OBSERVATIONS of z≃7 Galaxies GALAXIES",
abstract = "We present deep near-infrared spectroscopic observations of 13 luminous z ≃ 7 Lyman break galaxies (LBGs) (MUV ≃ -21) and a z ≃ 9.6 lensed LBG candidate, MACS1149-JD1, using the LBT/LUCI spectrograph in the multi-object mode and long-slit mode, respectively. The z ∼ 7 galaxies are selected in one of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/WIDE survey observations, the UKIRT Infrared Deep Sky Survey Ultra Deep Survey field, and MACS1159-JD1 is selected from the Cluster Lensing And Supernova survey with Hubble survey observations. With ∼ 4-5 hr integrations, the LBT spectra are sensitive to Ly α emission, with rest-frame equivalent width greater than 55 ł (EW0 > 55 ł) at z ≃ 7 and 90 (EW0 > 90 ł) at z ∼ 9.5. No Ly α emission is observed in any of the z ≃ 7 LBGs. After correcting the spectroscopic incompleteness, our measurements place an upper limit on the Ly α emission fraction o XLya (EW0 > 55 ł, z ≃ 7) < 9.8{\%} in luminous LBGs at z ≃ 7. This result is consistent with the lack of Lyα emission in z >7 LBGs in previous studies. Together with other measurements of the Lyα emission fraction in LBGs at z ≃7, this study puts a strong constraint on the fraction of luminous z ≃ 7 LBGs with large EWXLyα, X (EW 055 ł, z ≃ 7) 2.6+ 3.2-2.6 {\%}. We estimate the expected Lyα emission fraction at z≃7 by extrapolating the evolution of the fraction at low redshifts and find that the observed Lyα emission fraction is lower than the expected Lyα emission fraction at the 89{\%} significance?level, consistent with expectations if Lyα emission in z≃7 LBGs has been suppressed by neutral hydrogen in the intergalactic medium or optically thick absorbers around the galaxies. We do not find any strong Lyα emission feature at the redshift range of z≃7.3-9.7 in the MACSJ1159-JD1 spectrum, either. This is consistent with the conclusion that Lyα emission in the galaxy has been highly suppressed.",
keywords = "cosmology: observations, galaxies: evolution, galaxies: high-redshift",
author = "Fuyan Bian and Stark, {Daniel P} and Xiaohui Fan and Linhua Jiang and Benjamin Cl{\'e}ment and Eiichi Egami and Frye, {Brenda Louise} and Green, {Richard F.} and McGreer, {Ian D.} and Zheng Cai",
year = "2015",
month = "6",
day = "10",
doi = "10.1088/0004-637X/806/1/108",
language = "English (US)",
volume = "806",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - LBT/LUCI SPECTROSCOPIC OBSERVATIONS of z≃7 Galaxies GALAXIES

AU - Bian, Fuyan

AU - Stark, Daniel P

AU - Fan, Xiaohui

AU - Jiang, Linhua

AU - Clément, Benjamin

AU - Egami, Eiichi

AU - Frye, Brenda Louise

AU - Green, Richard F.

AU - McGreer, Ian D.

AU - Cai, Zheng

PY - 2015/6/10

Y1 - 2015/6/10

N2 - We present deep near-infrared spectroscopic observations of 13 luminous z ≃ 7 Lyman break galaxies (LBGs) (MUV ≃ -21) and a z ≃ 9.6 lensed LBG candidate, MACS1149-JD1, using the LBT/LUCI spectrograph in the multi-object mode and long-slit mode, respectively. The z ∼ 7 galaxies are selected in one of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/WIDE survey observations, the UKIRT Infrared Deep Sky Survey Ultra Deep Survey field, and MACS1159-JD1 is selected from the Cluster Lensing And Supernova survey with Hubble survey observations. With ∼ 4-5 hr integrations, the LBT spectra are sensitive to Ly α emission, with rest-frame equivalent width greater than 55 ł (EW0 > 55 ł) at z ≃ 7 and 90 (EW0 > 90 ł) at z ∼ 9.5. No Ly α emission is observed in any of the z ≃ 7 LBGs. After correcting the spectroscopic incompleteness, our measurements place an upper limit on the Ly α emission fraction o XLya (EW0 > 55 ł, z ≃ 7) < 9.8% in luminous LBGs at z ≃ 7. This result is consistent with the lack of Lyα emission in z >7 LBGs in previous studies. Together with other measurements of the Lyα emission fraction in LBGs at z ≃7, this study puts a strong constraint on the fraction of luminous z ≃ 7 LBGs with large EWXLyα, X (EW 055 ł, z ≃ 7) 2.6+ 3.2-2.6 %. We estimate the expected Lyα emission fraction at z≃7 by extrapolating the evolution of the fraction at low redshifts and find that the observed Lyα emission fraction is lower than the expected Lyα emission fraction at the 89% significance?level, consistent with expectations if Lyα emission in z≃7 LBGs has been suppressed by neutral hydrogen in the intergalactic medium or optically thick absorbers around the galaxies. We do not find any strong Lyα emission feature at the redshift range of z≃7.3-9.7 in the MACSJ1159-JD1 spectrum, either. This is consistent with the conclusion that Lyα emission in the galaxy has been highly suppressed.

AB - We present deep near-infrared spectroscopic observations of 13 luminous z ≃ 7 Lyman break galaxies (LBGs) (MUV ≃ -21) and a z ≃ 9.6 lensed LBG candidate, MACS1149-JD1, using the LBT/LUCI spectrograph in the multi-object mode and long-slit mode, respectively. The z ∼ 7 galaxies are selected in one of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/WIDE survey observations, the UKIRT Infrared Deep Sky Survey Ultra Deep Survey field, and MACS1159-JD1 is selected from the Cluster Lensing And Supernova survey with Hubble survey observations. With ∼ 4-5 hr integrations, the LBT spectra are sensitive to Ly α emission, with rest-frame equivalent width greater than 55 ł (EW0 > 55 ł) at z ≃ 7 and 90 (EW0 > 90 ł) at z ∼ 9.5. No Ly α emission is observed in any of the z ≃ 7 LBGs. After correcting the spectroscopic incompleteness, our measurements place an upper limit on the Ly α emission fraction o XLya (EW0 > 55 ł, z ≃ 7) < 9.8% in luminous LBGs at z ≃ 7. This result is consistent with the lack of Lyα emission in z >7 LBGs in previous studies. Together with other measurements of the Lyα emission fraction in LBGs at z ≃7, this study puts a strong constraint on the fraction of luminous z ≃ 7 LBGs with large EWXLyα, X (EW 055 ł, z ≃ 7) 2.6+ 3.2-2.6 %. We estimate the expected Lyα emission fraction at z≃7 by extrapolating the evolution of the fraction at low redshifts and find that the observed Lyα emission fraction is lower than the expected Lyα emission fraction at the 89% significance?level, consistent with expectations if Lyα emission in z≃7 LBGs has been suppressed by neutral hydrogen in the intergalactic medium or optically thick absorbers around the galaxies. We do not find any strong Lyα emission feature at the redshift range of z≃7.3-9.7 in the MACSJ1159-JD1 spectrum, either. This is consistent with the conclusion that Lyα emission in the galaxy has been highly suppressed.

KW - cosmology: observations

KW - galaxies: evolution

KW - galaxies: high-redshift

UR - http://www.scopus.com/inward/record.url?scp=84935000199&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84935000199&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/806/1/108

DO - 10.1088/0004-637X/806/1/108

M3 - Article

AN - SCOPUS:84935000199

VL - 806

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 108

ER -