%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 }