abbreviated We present a census of Ly\alpha\ emission at $z\gtrsim7$
utilizing deep near infrared HST grism spectroscopy from the first six
completed clusters of the Grism Lens-Amplified Survey from Space (GLASS). In
24/159 photometrically selected galaxies we detect emission lines consistent
with Ly\alpha\ in the GLASS spectra. Based on the distribution of
signal-to-noise ratios and on simulations we expect the completeness and the
purity of the sample to be 40-100% and 60-90%, respectively. For the objects
without detected emission lines we show that the observed (not corrected for
lensing magnification) 1$\sigma$ flux limits reaches
$5\times10^-18$erg/s/cm$^2$ per position angle over the full wavelength
range of GLASS (0.8-1.7$\mu$m). Based on the conditional probability of
Ly\alpha\ emission measured from the ground at $z\sim7$ we would have expected
12-18 Ly\alpha\ emitters. This is consistent with the number of detections,
within the uncertainties, confirming the drop in Ly\alpha\ emission with
respect to $z\sim6$. These candidates include a promising source at $z=8.1$.
The spatial extent of Ly\alpha\ in a deep stack of the most convincing
Ly\alpha\ emitters with $z\rangle=7.2$ is consistent with that of the
rest-frame UV continuum. Extended Ly$\alpha$ emission, if present, has a
surface brightness below our detection limit, consistent with the properties of
lower redshift comparison samples. From the stack we estimate upper limits on
rest-frame UV emission line ratios and find $f_CIV /
f_Ly$\alpha$ 0.32$ and $f_CIII /
f_Ly$\alpha$ 0.23$ in good agreement with other values
published in the literature.
Description
[1511.04205] The Grism Lens-Amplified Survey from Space (GLASS). III. A census of Ly\alpha\ Emission at $z\gtrsim$7 from HST Spectroscopy
%0 Generic
%1 schmidt2015grism
%A Schmidt, K. B.
%A Treu, T.
%A Bradač, M.
%A Vulcani, B.
%A Huang, K. H.
%A Hoag, A.
%A Maseda, M.
%A Guaita, L.
%A Pentericci, L.
%A Brammer, G. B.
%A Dijkstra, M.
%A Dressler, A.
%A Fontana, A.
%A Henry, A. L.
%A Jones, T. A.
%A Mason, C.
%A Trenti, M.
%A Wang, X.
%D 2015
%K emission high-z lya
%T The Grism Lens-Amplified Survey from Space (GLASS). III. A census of
Ly\alpha\ Emission at $z\gtrsim$7 from HST Spectroscopy
%U http://arxiv.org/abs/1511.04205
%X abbreviated We present a census of Ly\alpha\ emission at $z\gtrsim7$
utilizing deep near infrared HST grism spectroscopy from the first six
completed clusters of the Grism Lens-Amplified Survey from Space (GLASS). In
24/159 photometrically selected galaxies we detect emission lines consistent
with Ly\alpha\ in the GLASS spectra. Based on the distribution of
signal-to-noise ratios and on simulations we expect the completeness and the
purity of the sample to be 40-100% and 60-90%, respectively. For the objects
without detected emission lines we show that the observed (not corrected for
lensing magnification) 1$\sigma$ flux limits reaches
$5\times10^-18$erg/s/cm$^2$ per position angle over the full wavelength
range of GLASS (0.8-1.7$\mu$m). Based on the conditional probability of
Ly\alpha\ emission measured from the ground at $z\sim7$ we would have expected
12-18 Ly\alpha\ emitters. This is consistent with the number of detections,
within the uncertainties, confirming the drop in Ly\alpha\ emission with
respect to $z\sim6$. These candidates include a promising source at $z=8.1$.
The spatial extent of Ly\alpha\ in a deep stack of the most convincing
Ly\alpha\ emitters with $z\rangle=7.2$ is consistent with that of the
rest-frame UV continuum. Extended Ly$\alpha$ emission, if present, has a
surface brightness below our detection limit, consistent with the properties of
lower redshift comparison samples. From the stack we estimate upper limits on
rest-frame UV emission line ratios and find $f_CIV /
f_Ly$\alpha$ 0.32$ and $f_CIII /
f_Ly$\alpha$ 0.23$ in good agreement with other values
published in the literature.
@misc{schmidt2015grism,
abstract = {[abbreviated] We present a census of Ly\alpha\ emission at $z\gtrsim7$
utilizing deep near infrared HST grism spectroscopy from the first six
completed clusters of the Grism Lens-Amplified Survey from Space (GLASS). In
24/159 photometrically selected galaxies we detect emission lines consistent
with Ly\alpha\ in the GLASS spectra. Based on the distribution of
signal-to-noise ratios and on simulations we expect the completeness and the
purity of the sample to be 40-100% and 60-90%, respectively. For the objects
without detected emission lines we show that the observed (not corrected for
lensing magnification) 1$\sigma$ flux limits reaches
$5\times10^{-18}$erg/s/cm$^{2}$ per position angle over the full wavelength
range of GLASS (0.8-1.7$\mu$m). Based on the conditional probability of
Ly\alpha\ emission measured from the ground at $z\sim7$ we would have expected
12-18 Ly\alpha\ emitters. This is consistent with the number of detections,
within the uncertainties, confirming the drop in Ly\alpha\ emission with
respect to $z\sim6$. These candidates include a promising source at $z=8.1$.
The spatial extent of Ly\alpha\ in a deep stack of the most convincing
Ly\alpha\ emitters with $\langle z\rangle=7.2$ is consistent with that of the
rest-frame UV continuum. Extended Ly$\alpha$ emission, if present, has a
surface brightness below our detection limit, consistent with the properties of
lower redshift comparison samples. From the stack we estimate upper limits on
rest-frame UV emission line ratios and find $f_\textrm{CIV} /
f_\textrm{Ly${\alpha}$} \lesssim 0.32$ and $f_\textrm{CIII]} /
f_\textrm{Ly$\alpha$} \lesssim 0.23$ in good agreement with other values
published in the literature.},
added-at = {2015-11-16T19:39:18.000+0100},
author = {Schmidt, K. B. and Treu, T. and Bradač, M. and Vulcani, B. and Huang, K. H. and Hoag, A. and Maseda, M. and Guaita, L. and Pentericci, L. and Brammer, G. B. and Dijkstra, M. and Dressler, A. and Fontana, A. and Henry, A. L. and Jones, T. A. and Mason, C. and Trenti, M. and Wang, X.},
biburl = {https://www.bibsonomy.org/bibtex/21e99303ad9dcf7e0d1c846664b8d06d4/miki},
description = {[1511.04205] The Grism Lens-Amplified Survey from Space (GLASS). III. A census of Ly\alpha\ Emission at $z\gtrsim$7 from HST Spectroscopy},
interhash = {019b0d900cfbe5b451adcd46bcbd820c},
intrahash = {1e99303ad9dcf7e0d1c846664b8d06d4},
keywords = {emission high-z lya},
note = {cite arxiv:1511.04205Comment: Accepted for publication in ApJ, 23 pages, 11 figures, 6 tables},
timestamp = {2015-11-16T19:39:18.000+0100},
title = {The Grism Lens-Amplified Survey from Space (GLASS). III. A census of
Ly\alpha\ Emission at $z\gtrsim$7 from HST Spectroscopy},
url = {http://arxiv.org/abs/1511.04205},
year = 2015
}