Rights statement: This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Jorryt Matthee, David Sobral, Matthew Hayes, Gabriele Pezzulli, Max Gronke, Daniel Schaerer, Rohan P Naidu, Huub Röttgering, João Calhau, Ana Paulino-Afonso, Sérgio Santos, Ricardo Amorín, The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: what makes a galaxy a Lyman α emitter?, Monthly Notices of the Royal Astronomical Society, Volume 505, Issue 1, July 2021, Pages 1382–1412, https://doi.org/10.1093/mnras/stab1304 is available online at: https://academic.oup.com/mnras/article/505/1/1382/6273158
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - The X-SHOOTER Lyman-$α$ survey at z=2 (XLS-z2) I
T2 - what makes a galaxy a Lyman α emitter?
AU - Matthee, Jorryt
AU - Sobral, David
AU - Hayes, Matthew
AU - Pezzulli, Gabriele
AU - Gronke, Max
AU - Schaerer, Daniel
AU - Naidu, Rohan P.
AU - Röttgering, Huub
AU - Calhau, João
AU - Paulino-Afonso, Ana
AU - Santos, Sérgio
AU - Amorín, Ricardo
N1 - This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Jorryt Matthee, David Sobral, Matthew Hayes, Gabriele Pezzulli, Max Gronke, Daniel Schaerer, Rohan P Naidu, Huub Röttgering, João Calhau, Ana Paulino-Afonso, Sérgio Santos, Ricardo Amorín, The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: what makes a galaxy a Lyman α emitter?, Monthly Notices of the Royal Astronomical Society, Volume 505, Issue 1, July 2021, Pages 1382–1412, https://doi.org/10.1093/mnras/stab1304 is available online at: https://academic.oup.com/mnras/article/505/1/1382/6273158
PY - 2021/7/31
Y1 - 2021/7/31
N2 - We present the first results from the X-SHOOTER Lyman-$\alpha$ survey at $z=2$ (XLS-$z2$). XLS-$z2$ is a deep spectroscopic survey of 35 Lyman-$\alpha$ emitters (LAEs) utilising $\approx90$ hours of exposure time with VLT/X-SHOOTER and covers rest-frame Ly$\alpha$ to H$\alpha$ emission with R$\approx4000$. We present the sample selection, the observations and the data reduction. Systemic redshifts are measured from rest-frame optical lines for 33/35 sources. In the stacked spectrum, our LAEs are characterised by an interstellar medium with little dust, a low metallicity and a high ionisation state. The ionising sources are young hot stars that power strong emission-lines in the optical and high ionisation lines in the UV. The LAEs exhibit clumpy UV morphologies and have outflowing kinematics with blue-shifted SiII absorption, a broad [OIII] component and a red-skewed Ly$\alpha$ line. Typically 30 % of the Ly$\alpha$ photons escape, of which one quarter on the blue side of the systemic velocity. A fraction of Ly$\alpha$ photons escapes directly at the systemic suggesting clear channels enabling a $\approx10$ % escape of ionising photons, consistent with an inference based on MgII. A combination of a low effective HI column density, a low dust content and young star-burst determine whether a star forming galaxy is observed as a LAE. The first is possibly related to outflows and/or a fortunate viewing angle, while we find that the latter two in LAEs are typical for their stellar mass of 10$^9$ M$_{\odot}$.
AB - We present the first results from the X-SHOOTER Lyman-$\alpha$ survey at $z=2$ (XLS-$z2$). XLS-$z2$ is a deep spectroscopic survey of 35 Lyman-$\alpha$ emitters (LAEs) utilising $\approx90$ hours of exposure time with VLT/X-SHOOTER and covers rest-frame Ly$\alpha$ to H$\alpha$ emission with R$\approx4000$. We present the sample selection, the observations and the data reduction. Systemic redshifts are measured from rest-frame optical lines for 33/35 sources. In the stacked spectrum, our LAEs are characterised by an interstellar medium with little dust, a low metallicity and a high ionisation state. The ionising sources are young hot stars that power strong emission-lines in the optical and high ionisation lines in the UV. The LAEs exhibit clumpy UV morphologies and have outflowing kinematics with blue-shifted SiII absorption, a broad [OIII] component and a red-skewed Ly$\alpha$ line. Typically 30 % of the Ly$\alpha$ photons escape, of which one quarter on the blue side of the systemic velocity. A fraction of Ly$\alpha$ photons escapes directly at the systemic suggesting clear channels enabling a $\approx10$ % escape of ionising photons, consistent with an inference based on MgII. A combination of a low effective HI column density, a low dust content and young star-burst determine whether a star forming galaxy is observed as a LAE. The first is possibly related to outflows and/or a fortunate viewing angle, while we find that the latter two in LAEs are typical for their stellar mass of 10$^9$ M$_{\odot}$.
KW - astro-ph.GA
U2 - 10.1093/mnras/stab1304
DO - 10.1093/mnras/stab1304
M3 - Journal article
VL - 505
SP - 1382
EP - 1412
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 1
ER -