A Flux-limited Sample of z ~ 1 Lyα Emitting Galaxies in the Chandra Deep Field South

Type Journal Article
Names A. J. Barger, L. L. Cowie, I. G. B. Wold
Publication The Astrophysical Journal
Volume 749
Issue 2
Pages 106
Date April 1, 2012
URL http://adsabs.harvard.edu/abs/2012ApJ...749..106B
Library Catalog NASA ADS
Abstract We describe a method for obtaining a flux-limited sample of Lyα emitters from Galaxy Evolution Explorer (GALEX) grism data. We show that the multiple GALEX grism images can be converted into a three-dimensional (two spatial axes and one wavelength axis) data cube. The wavelength slices may then be treated as narrowband images and searched for emission-line galaxies. For the GALEX NUV grism data, the method provides a Lyα flux-limited sample over the redshift range z = 0.67-1.16. We test the method on the Chandra Deep Field South field, where we find 28 Lyα emitters with faint continuum magnitudes (NUV > 22) that are not present in the GALEX pipeline sample. We measure the completeness by adding artificial emitters and measuring the fraction recovered. We find that we have an 80% completeness above a Lyα flux of 10–15 erg cm–2 s–1. We use the UV spectra and the available X-ray data and optical spectra to estimate the fraction of active galactic nuclei in the selection. We report the first detection of a giant Lyα blob at z < 1, though we find that these objects are much less common at z = 1 than at z = 3. Finally, we compute limits on the z ~ 1 Lyα luminosity function and confirm that there is a dramatic evolution in the luminosity function over the redshift range z = 0-1. Based in part on data obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non Hubble Space Telescope data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts. This research used the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency.
Tags GALAXIES: EVOLUTION, cosmology: observations, galaxies: active, galaxies: distances and redshifts, galaxies: starburst
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