Inside the bubble: exploring the environments of reionisation-era Lyman- α emitting galaxies with JADES and FRESCO
Author
Witstok, J.Smit, R.
Saxena, A.
Jones, G.C.
Helton, J.M.
Sun, F.
Maiolino, R.
Kumari, N.
Stark, D.P.
Bunker, A.J.
Arribas, S.
Baker, W.M.
Bhatawdekar, R.
Boyett, K.
Cameron, A.J.
Carniani, S.
Charlot, S.

Chevallard, J.
Curti, M.
Curtis-Lake, E.
Eisenstein, D.J.
Endsley, R.
Hainline, K.
Ji, Z.
Johnson, B.D.
Looser, T.J.
Nelson, E.
Perna, M.
Rix, H.-W.
Robertson, B.E.
Sandles, L.
Scholtz, J.
Simmonds, C.
Tacchella, S.
Übler, H.

Williams, C.C.
Willmer, C.N.A.
Willott, C.
Affiliation
Steward Observatory, University of ArizonaIssue Date
2024-01-31
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EDP SciencesCitation
A&A 682, A40 (2024)Journal
Astronomy and AstrophysicsRights
© The Authors 2024. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present a study of the environments of 17 Lyman-α emitting galaxies (LAEs) in the reionisation-era (5.8 < z < 8) identified by JWST/NIRSpec as part of the JWST Advanced Deep Extragalactic Survey (JADES). Unless situated in sufficiently (re)ionised regions, Lyman-α emission from these galaxies would be strongly absorbed by neutral gas in the intergalactic medium (IGM). We conservatively estimate sizes of the ionised regions required to reconcile the relatively low Lyman-α velocity offsets (Γ vLyα < 300kms-1) with moderately high Lyman-α escape fractions (fesc,Lyα > 5%) observed in our sample of LAEs, suggesting the presence of ionised hydrogen along the line of sight towards at least eight out of 17 LAEs. We find minimum physical 'bubble'sizes of the order of Rion ∼ 0.1- 1pMpc are required in a patchy reionisation scenario where ionised bubbles containing the LAEs are embedded in a fully neutral IGM. Around half of the LAEs in our sample are found to coincide with large-scale galaxy overdensities seen in FRESCO at z ∼ 5.8- 5.9 and z ∼ 7.3, suggesting Lyman-α transmission is strongly enhanced in such overdense regions, and underlining the importance of LAEs as tracers of the first large-scale ionised bubbles. Considering only spectroscopically confirmed galaxies, we find our sample of UV-faint LAEs (MUV ≳ -20mag) and their direct neighbours are generally not able to produce the required ionised regions based on the Lyman-α transmission properties, suggesting lower-luminosity sources likely play an important role in carving out these bubbles. These observations demonstrate the combined power of JWST multi-object and slitless spectroscopy in acquiring a unique view of the early Universe during cosmic reionisation via the most distant LAEs. © The Authors 2024.Note
Open access articleISSN
0004-6361Version
Final Published Versionae974a485f413a2113503eed53cd6c53
10.1051/0004-6361/202347176
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Except where otherwise noted, this item's license is described as © The Authors 2024. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License.