Details

Autor(en) / Beteiligte

• McGreer, Ian D
• Clément, Benjamin
• Mainali, Ramesh
• Stark, Daniel P
• Gronke, Max
• Dijkstra, Mark
• Fan, Xiaohui
• Bian, Fuyan
• Frye, Brenda
• Jiang, Linhua
• Kneib, Jean-Paul
• Limousin, Marceau
• Walth, Gregory

Titel

A bright lensed galaxy at z = 5.4 with strong Lyα emission

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2018-09

Ort / Verlag

Blackwell Publishing

Erscheinungsjahr

2018

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• We present a detailed study of an unusually bright, lensed galaxy at z = 5.424 discovered within the CFHTLS imaging survey. With an observed flux ofiAB =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 >10−16erg 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] λ1486 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 few kpc 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.