TY - JOUR
T1 - Jades: The production and escape of ionizing photons from faint Lyman-alpha emitters in the epoch of reionization
AU - Saxena, Aayush
AU - Bunker, Andrew J.
AU - Jones, Gareth C.
AU - Stark, Daniel P.
AU - Cameron, Alex J.
AU - Witstok, Joris
AU - Arribas, Santiago
AU - Baker, William M.
AU - Baum, Stefi
AU - Bhatawdekar, Rachana
AU - Bowler, Rebecca
AU - Boyett, Kristan
AU - Carniani, Stefano
AU - Charlot, Stephane
AU - Chevallard, Jacopo
AU - Curti, Mirko
AU - Curtis-Lake, Emma
AU - Eisenstein, Daniel J.
AU - Endsley, Ryan
AU - Hainline, Kevin
AU - Helton, Jakob M.
AU - Johnson, Benjamin D.
AU - Kumari, Nimisha
AU - Looser, Tobias J.
AU - Maiolino, Roberto
AU - Rieke, Marcia
AU - Rix, Hans-Walter
AU - Robertson, Brant E.
AU - Sandles, Lester
AU - Simmonds, Charlotte
AU - Smit, Renske
AU - Tacchella, Sandro
AU - Williams, Christina C.
AU - Willmer, Christopher N. A.
AU - Willott, Chris
N1 - © The Authors 2024. This is Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
PY - 2024/4/5
Y1 - 2024/4/5
N2 - We present the properties of 17 faint Ly$\alpha$ emitting galaxies (LAEs) at $z>5.8$ from the JWST Advanced Deep Extragalactic Survey (JADES) in the Hubble Ultra Deep Field/GOODS-S. These LAEs span a redshift range $z\approx5.8-8.0$ and a UV magnitude range $M_{UV}\approx-17$ to $-20.6$, with the Ly$\alpha$ equivalent width (EW) in the range $\approx 25-350$ \AA. The detection of other rest-optical emission lines in the spectra of these LAEs enables the determination of accurate systemic redshifts and Ly{\alpha} velocity offsets, as well as the physical and chemical composition of their stars and interstellar media. These faint LAEs are consistent with metal-poor systems with high ionization parameters, similar to the general galaxy population at $z>6$. We measured an average ionizing photon production efficiency, log($\xi_\rm{ion}$/erg$^{-1}$ Hz) $\approx25.57$ across our LAEs, which does not evolve strongly with redshift. We report an anti-correlation between the Ly$\alpha$ escape fraction (f_\rm{esc}) and the velocity offset from systemic redshift, consistent with model expectations. We further find that the strength and velocity offset of Ly$\alpha$ are neither correlated with galaxy spectroscopic properties nor with $\xi_\rm{ion}$. We find a decrease in $f_\rm{esc}$(Ly$\alpha$) with redshift, indicative of decreasing sizes of ionized bubbles around LAEs at high redshifts. We used a range of galaxy properties to predict Lyman continuum $f_\rm{esc}$ for our LAEs, finding that the ionizing photon output into the intergalactic medium remains roughly constant across the observed Ly$\alpha$ EW, showing a mild increase at fainter M$_{UV}$ and at higher redshifts. We derived correlations between the ionizing photon output from LAEs and $M_{UV}$, Ly$\alpha$ EW and redshifts, which can be used to constrain the ionizing photon contribution of LAEs at $z > 6$ towards cosmic reionization.
AB - We present the properties of 17 faint Ly$\alpha$ emitting galaxies (LAEs) at $z>5.8$ from the JWST Advanced Deep Extragalactic Survey (JADES) in the Hubble Ultra Deep Field/GOODS-S. These LAEs span a redshift range $z\approx5.8-8.0$ and a UV magnitude range $M_{UV}\approx-17$ to $-20.6$, with the Ly$\alpha$ equivalent width (EW) in the range $\approx 25-350$ \AA. The detection of other rest-optical emission lines in the spectra of these LAEs enables the determination of accurate systemic redshifts and Ly{\alpha} velocity offsets, as well as the physical and chemical composition of their stars and interstellar media. These faint LAEs are consistent with metal-poor systems with high ionization parameters, similar to the general galaxy population at $z>6$. We measured an average ionizing photon production efficiency, log($\xi_\rm{ion}$/erg$^{-1}$ Hz) $\approx25.57$ across our LAEs, which does not evolve strongly with redshift. We report an anti-correlation between the Ly$\alpha$ escape fraction (f_\rm{esc}) and the velocity offset from systemic redshift, consistent with model expectations. We further find that the strength and velocity offset of Ly$\alpha$ are neither correlated with galaxy spectroscopic properties nor with $\xi_\rm{ion}$. We find a decrease in $f_\rm{esc}$(Ly$\alpha$) with redshift, indicative of decreasing sizes of ionized bubbles around LAEs at high redshifts. We used a range of galaxy properties to predict Lyman continuum $f_\rm{esc}$ for our LAEs, finding that the ionizing photon output into the intergalactic medium remains roughly constant across the observed Ly$\alpha$ EW, showing a mild increase at fainter M$_{UV}$ and at higher redshifts. We derived correlations between the ionizing photon output from LAEs and $M_{UV}$, Ly$\alpha$ EW and redshifts, which can be used to constrain the ionizing photon contribution of LAEs at $z > 6$ towards cosmic reionization.
KW - astro-ph.GA
U2 - 10.1051/0004-6361/202347132
DO - 10.1051/0004-6361/202347132
M3 - Article
SN - 0004-6361
VL - 684
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A84
ER -