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arXiv · 1606.03526

An Ultraluminous Lyman Alpha Emitter with a Blue Wing at z=6.6

E. M. Hu·L. L. Cowie·A. Songaila·A. J. Barger·B. Rosenwasser·I. Wold
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Abstract

We report the detection of the most luminous high-redshift Lyman Alpha Emitting galaxy (LAE) yet seen, with log L(Ly alpha) = 43.9 ergs/s. The galaxy -- COSMOS Lyman alpha 1, or COLA1 -- was detected in a search for ultra-luminous LAEs with Hyper Suprime-Cam on the Subaru telescope. It was confirmed to lie at z = 6.593 based on a Lyman alpha line detection obtained from followup spectroscopy with the DEIMOS spectrograph on Keck2. COLA1 is the first very high-redshift LAE to show a multi-component Lyman alpha line profile with a blue wing, which suggests that it could lie in a highly ionized region of the intergalactic medium and could have significant infall. If this interpretation is correct, then ultra-luminous LAEs like COLA1 offer a unique opportunity to determine the properties of the HII regions around these galaxies which will help in understanding the ionization of the z ~ 7 intergalactic medium.

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E. M. Hu, L. L. Cowie, A. Songaila, A. J. Barger, B. Rosenwasser, I. Wold. 2016-06-11. An Ultraluminous Lyman Alpha Emitter with a Blue Wing at z=6.6. https://doi.org/10.3847/2041-8205/825/1/l7

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