Early Results from GLASS-JWST. XXII. Rest-frame UV–Optical Spectral Properties of Lyα Emitting Galaxies at 3 < z < 6

Namrata Roy; Alaina Henry; Tommaso Treu; Tucker Jones; Gonzalo Prieto-Lyon; Charlotte Mason; Tim Heckman; Themiya Nanayakkara; Laura Pentericci; Sara Mascia; Maruša Bradač; Eros Vanzella; Claudia Scarlata; Kit Boyett; Michele Trenti; Xin Wang

doi:10.3847/2041-8213/acdbce

The Astrophysical Journal Letters (Jan 2023)

Early Results from GLASS-JWST. XXII. Rest-frame UV–Optical Spectral Properties of Lyα Emitting Galaxies at 3 < z < 6

Namrata Roy,
Alaina Henry,
Tommaso Treu,
Tucker Jones,
Gonzalo Prieto-Lyon,
Charlotte Mason,
Tim Heckman,
Themiya Nanayakkara,
Laura Pentericci,
Sara Mascia,
Maruša Bradač,
Eros Vanzella,
Claudia Scarlata,
Kit Boyett,
Michele Trenti,
Xin Wang

Affiliations

Namrata Roy: ORCiD; Center for Astrophysical Sciences, Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA ; [email protected]
Alaina Henry: ORCiD; Center for Astrophysical Sciences, Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA ; [email protected]; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Tommaso Treu: ORCiD; Department of Physics and Astronomy, University of California , Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095, USA
Tucker Jones: ORCiD; Department of Physics and Astronomy, University of California Davis , 1 Shields Avenue, Davis, CA 95616, USA
Gonzalo Prieto-Lyon: ORCiD; Cosmic Dawn Center (DAWN), Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, DK-2200 Copenhagen N, Denmark
Charlotte Mason: ORCiD; Cosmic Dawn Center (DAWN), Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, DK-2200 Copenhagen N, Denmark
Tim Heckman: ORCiD; Center for Astrophysical Sciences, Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA ; [email protected]
Themiya Nanayakkara: ORCiD; Centre for Astrophysics and Supercomputing, Swinburne University of Technology , PO Box 218, Hawthorn, VIC 3122, Australia
Laura Pentericci: ORCiD; INAF—Osservatorio Astronomico di Roma , via di Frascati 33, I-00078 Monte Porzio Catone, Italy
Sara Mascia: ORCiD; INAF—Osservatorio Astronomico di Roma , via di Frascati 33, I-00078 Monte Porzio Catone, Italy
Maruša Bradač: ORCiD; Department of Physics and Astronomy, University of California Davis , 1 Shields Avenue, Davis, CA 95616, USA; University of Ljubljana , Department of Mathematics and Physics, Jadranska ulica 19, SI-1000 Ljubljana, Slovenia
Eros Vanzella: ORCiD; INAF—OAS , Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, via Gobetti 93/3, I-40129 Bologna, Italy
Claudia Scarlata: ORCiD; School of Physics and Astronomy, University of Minnesota , Minneapolis, MN 55455, USA
Kit Boyett: ORCiD; School of Physics, University of Melbourne , Parkville 3010, VIC, Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia
Michele Trenti: ORCiD; School of Physics, University of Melbourne , Parkville 3010, VIC, Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia
Xin Wang: ORCiD; School of Astronomy and Space Science, University of Chinese Academy of Sciences (UCAS) , Beijing 100049, People’s Republic of China; National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China; Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University , Beijing 102206, People’s Republic of China

DOI: https://doi.org/10.3847/2041-8213/acdbce
Journal volume & issue: Vol. 952, no. 1
p. L14

Abstract

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Ly α emission is possibly the best indirect diagnostic of Lyman continuum (LyC) escape since the conditions that favor the escape of Ly α photons are often the same that allow for the escape of LyC photons. In this work, we present the rest-frame UV–optical spectral characteristics of 11 Ly α emitting galaxies at 3 < z < 6—the redshift range that optimizes between intergalactic medium attenuation effects and temporal proximity to the epoch of reionization. From a combined analysis of JWST/NIRSpec and MUSE data, we present the Ly α escape fraction and study its correlation with other physical properties of galaxies that might facilitate Ly α escape. We find that our galaxies have low masses (80% of the sample with ${\mathrm{log}}_{10}\ {M}_{\star }\lt 9.5\ {M}_{\odot }$ ), compact sizes (median R _e ∼ 0.7 kpc), low dust content, moderate [O iii ]/[O ii ] flux ratios (mean ∼ 6.8 ± 1.2), and moderate Ly α escape fractions (mean ${f}_{\mathrm{esc}}^{\mathrm{Ly}\alpha }\ \sim $ 0.11). Our sample shows characteristics that are broadly consistent with low-redshift galaxies with Ly α emission, which are termed as “analogs” of the high-redshift population. We predict the LyC escape fraction in our sample to be low (0.03–0.07), although larger samples in the postreionization epoch are needed to confirm these trends.

Published in The Astrophysical Journal Letters

ISSN: 2041-8205 (Print); 2041-8213 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/2041-8205

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