We present a flux-limited sample of $z\sim0.3$ Ly$\alpha$ emitters (LAEs)
from Galaxy Evolution Explorer (GALEX) grism spectroscopic data. The published
GALEX $z\sim0.3$ LAE sample is pre-selected from continuum-bright objects and
thus is biased against high equivalent width (EW) LAEs. We remove this
continuum pre-selection and compute the EW distribution and the luminosity
function of the Ly$\alpha$ emission line directly from our sample. We examine
the evolution of these quantities from $z\sim0.3$ to $2.2$ and find that the EW
distribution shows little evidence for evolution over this redshift range. As
shown by previous studies, the Ly$\alpha$ luminosity density from star-forming
galaxies declines rapidly with declining redshift. However, we find that the
decline in Ly$\alpha$ luminosity density from $z=2.2$ to $z=0.3$ may simply
mirror the decline seen in the H$\alpha$ luminosity density from $z=2.2$ to
$z=0.4$, implying little change in the volumetric Ly$\alpha$ escape fraction.
Finally, we show that the observed Ly$\alpha$ luminosity density from AGNs is
comparable to the observed Ly$\alpha$ luminosity density from star-forming
galaxies at $z=0.3$. We suggest that this significant contribution from AGNs to
the total observed Ly$\alpha$ luminosity density persists out to $z\sim2.2$.
Description
[1709.06092] A Faint Flux-Limited Lyman Alpha Emitter Sample at $z\sim0.3$
%0 Generic
%1 wold2017faint
%A Wold, Isak G. B.
%A Finkelstein, Steven L.
%A Barger, Amy J.
%A Cowie, Lennox L.
%A Rosenwasser, Benjamin
%D 2017
%K Lya evolution function luminosity
%T A Faint Flux-Limited Lyman Alpha Emitter Sample at $z\sim0.3$
%U http://arxiv.org/abs/1709.06092
%X We present a flux-limited sample of $z\sim0.3$ Ly$\alpha$ emitters (LAEs)
from Galaxy Evolution Explorer (GALEX) grism spectroscopic data. The published
GALEX $z\sim0.3$ LAE sample is pre-selected from continuum-bright objects and
thus is biased against high equivalent width (EW) LAEs. We remove this
continuum pre-selection and compute the EW distribution and the luminosity
function of the Ly$\alpha$ emission line directly from our sample. We examine
the evolution of these quantities from $z\sim0.3$ to $2.2$ and find that the EW
distribution shows little evidence for evolution over this redshift range. As
shown by previous studies, the Ly$\alpha$ luminosity density from star-forming
galaxies declines rapidly with declining redshift. However, we find that the
decline in Ly$\alpha$ luminosity density from $z=2.2$ to $z=0.3$ may simply
mirror the decline seen in the H$\alpha$ luminosity density from $z=2.2$ to
$z=0.4$, implying little change in the volumetric Ly$\alpha$ escape fraction.
Finally, we show that the observed Ly$\alpha$ luminosity density from AGNs is
comparable to the observed Ly$\alpha$ luminosity density from star-forming
galaxies at $z=0.3$. We suggest that this significant contribution from AGNs to
the total observed Ly$\alpha$ luminosity density persists out to $z\sim2.2$.
@misc{wold2017faint,
abstract = {We present a flux-limited sample of $z\sim0.3$ Ly$\alpha$ emitters (LAEs)
from Galaxy Evolution Explorer (GALEX) grism spectroscopic data. The published
GALEX $z\sim0.3$ LAE sample is pre-selected from continuum-bright objects and
thus is biased against high equivalent width (EW) LAEs. We remove this
continuum pre-selection and compute the EW distribution and the luminosity
function of the Ly$\alpha$ emission line directly from our sample. We examine
the evolution of these quantities from $z\sim0.3$ to $2.2$ and find that the EW
distribution shows little evidence for evolution over this redshift range. As
shown by previous studies, the Ly$\alpha$ luminosity density from star-forming
galaxies declines rapidly with declining redshift. However, we find that the
decline in Ly$\alpha$ luminosity density from $z=2.2$ to $z=0.3$ may simply
mirror the decline seen in the H$\alpha$ luminosity density from $z=2.2$ to
$z=0.4$, implying little change in the volumetric Ly$\alpha$ escape fraction.
Finally, we show that the observed Ly$\alpha$ luminosity density from AGNs is
comparable to the observed Ly$\alpha$ luminosity density from star-forming
galaxies at $z=0.3$. We suggest that this significant contribution from AGNs to
the total observed Ly$\alpha$ luminosity density persists out to $z\sim2.2$.},
added-at = {2017-09-20T11:53:14.000+0200},
author = {Wold, Isak G. B. and Finkelstein, Steven L. and Barger, Amy J. and Cowie, Lennox L. and Rosenwasser, Benjamin},
biburl = {https://www.bibsonomy.org/bibtex/29ad26ea2934ae75a119ed9ed5d18edf5/miki},
description = {[1709.06092] A Faint Flux-Limited Lyman Alpha Emitter Sample at $z\sim0.3$},
interhash = {d9739ab65c01448f0f6228f444a9a82a},
intrahash = {9ad26ea2934ae75a119ed9ed5d18edf5},
keywords = {Lya evolution function luminosity},
note = {cite arxiv:1709.06092Comment: 27 pages, 19 figures, accepted for publication in ApJ},
timestamp = {2017-09-20T11:53:14.000+0200},
title = {A Faint Flux-Limited Lyman Alpha Emitter Sample at $z\sim0.3$},
url = {http://arxiv.org/abs/1709.06092},
year = 2017
}