TY - JOUR
T1 - A bright-lensed galaxy at z = 5.4 with strong Ly α emission
AU - McGreer, Ian D.
AU - Clément, Benjamin
AU - Mainali, Ramesh
AU - Stark, Daniel P.
AU - Gronke, Max
AU - Dijkstra, Mark
AU - Fan, Xiaohui
AU - Bian, Fuyan
AU - Frye, Brenda
AU - Jiang, Linhua
AU - Kneib, Jean Paul
AU - Limousin, Marceau
AU - Walth, Gregory
N1 - Publisher Copyright:
© 2018 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society.
PY - 2018/9/1
Y1 - 2018/9/1
N2 - We present a detailed study of an unusually bright, lensed galaxy at z=5.424 discoveredwithin theCFHTLSimaging survey.With an observed flux of iAB =23.0, J141446.82+544631.9 is one of the brightest galaxies known at z > 5. It is characterized by strong Ly α emission, reaching a peak in (observed) flux density of > 10-16 erg s-1 cm-2Å-1. A deep optical spectrum from the Large Binocular Telescope places strong constraints on NV and C IV emission, disfavouring an Active Galactic Nucleus (AGN) source for the emission. However, a detection of the NIV] λ 1486 emission line indicates a hard ionizing continuum, possibly from hot, massive stars. Resolved imaging from HST deblends the galaxy from a foreground interloper; these observations include narrowband imaging of the Ly α emission, which is marginally resolved on approximately fewkpc scales and has EW0 ~ 260 Å. The Ly α emission extends over ~ 2000 km s-1 and is broadly consistent with expanding shell models. Spectral energy distribution fitting that includes Spitzer/IRAC photometry suggests a complex star formation history that includes both a recent burst and an evolved population. J1414+5446 lies 30 arcsec from the centre of a known lensing cluster in the CFHTLS; combined with the foreground contribution, this leads to a highly uncertain estimate for the lensing magnification in the range 5 ≲ μ ≲ 25. Because of its unusual brightness, J1414+5446 affords unique opportunities for detailed study of an individual galaxy near the epoch of re-ionization and a preview of what can be expected from upcoming wide-area surveys that will yield hundreds of similar objects.
AB - We present a detailed study of an unusually bright, lensed galaxy at z=5.424 discoveredwithin theCFHTLSimaging survey.With an observed flux of iAB =23.0, J141446.82+544631.9 is one of the brightest galaxies known at z > 5. It is characterized by strong Ly α emission, reaching a peak in (observed) flux density of > 10-16 erg s-1 cm-2Å-1. A deep optical spectrum from the Large Binocular Telescope places strong constraints on NV and C IV emission, disfavouring an Active Galactic Nucleus (AGN) source for the emission. However, a detection of the NIV] λ 1486 emission line indicates a hard ionizing continuum, possibly from hot, massive stars. Resolved imaging from HST deblends the galaxy from a foreground interloper; these observations include narrowband imaging of the Ly α emission, which is marginally resolved on approximately fewkpc scales and has EW0 ~ 260 Å. The Ly α emission extends over ~ 2000 km s-1 and is broadly consistent with expanding shell models. Spectral energy distribution fitting that includes Spitzer/IRAC photometry suggests a complex star formation history that includes both a recent burst and an evolved population. J1414+5446 lies 30 arcsec from the centre of a known lensing cluster in the CFHTLS; combined with the foreground contribution, this leads to a highly uncertain estimate for the lensing magnification in the range 5 ≲ μ ≲ 25. Because of its unusual brightness, J1414+5446 affords unique opportunities for detailed study of an individual galaxy near the epoch of re-ionization and a preview of what can be expected from upcoming wide-area surveys that will yield hundreds of similar objects.
KW - (Cosmology:) dark ages, re-ionization, first stars
KW - Galaxies: ISM-galaxies: groups: individual: SL2S J141447+544703
KW - Galaxies: high-redshift
KW - Galaxies: individual: CFHTLS J141446.82+544631.9
KW - Gravitational lensing: strong.
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U2 - 10.1093/mnras/sty1411
DO - 10.1093/mnras/sty1411
M3 - Article
AN - SCOPUS:85051479326
SN - 0035-8711
VL - 479
SP - 435
EP - 453
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -