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arXiv · 1011.0430

The HETDEX Pilot Survey. II. The Evolution of the Ly-alpha Escape Fraction from the UV Slope and Luminosity Function of 1.9<z<3.8 LAEs

Guillermo A. Blanc·Joshua Adams·Karl Gebhardt·Gary J. Hill·Niv Drory·Lei Hao·Ralf Bender·Robin Ciardullo·Steven L. Finkelstein·Eric Gawiser·Caryl Gronwall·Ulrich Hopp·Donghui Jeong·Ralf Kelzenberg·Eiichiro Komatsu·Phillip MacQueen·Jeremy D. Murphy·Martin M. Roth·Donald P. Schneider·Joseph Tufts
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Abstract

We study the escape of Ly-alpha photons from Ly-alpha emitting galaxies (LAEs) and the overall galaxy population using a sample of 99 LAEs at 1.9<z<3.8 detected through integral-field spectroscopy of blank fields by the HETDEX Pilot Survey. For 89 LAEs showing counterparts in deep broad-band images we measure the rest-frame UV luminosity and the UV slope, which we use to estimate E(B-V) under the assumption of a constant intrinsic UV slope for LAEs. These two quantities are used to measure the dust-corrected star formation rate (SFR). A comparison between the observed Ly-alpha luminosity and that predicted by the dust-corrected SFR yields the Ly-alpha escape fraction. We also measure the Ly-alpha luminosity function. Integration of the luminosity function provides a measurement of the Ly-alpha luminosity density across our redshift range. We combine our data with that from other surveys at 0.3<z<7.7 to trace the evolution of the Ly-alpha luminosity density. We then compare it to that expected from the star-formation history of the universe in order to characterize the evolution of the Ly-alpha escape fraction of the overall galaxy population [abriged]

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Guillermo A. Blanc, Joshua Adams, Karl Gebhardt, Gary J. Hill, Niv Drory, Lei Hao, Ralf Bender, Robin Ciardullo, Steven L. Finkelstein, Eric Gawiser, Caryl Gronwall, Ulrich Hopp, Donghui Jeong, Ralf Kelzenberg, Eiichiro Komatsu, Phillip MacQueen, Jeremy D. Murphy, Martin M. Roth, Donald P. Schneider, Joseph Tufts. 2010-11-01. The HETDEX Pilot Survey. II. The Evolution of the Ly-alpha Escape Fraction from the UV Slope and Luminosity Function of 1.9<z<3.8 LAEs. https://doi.org/10.1088/0004-637x/736/1/31

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