Stellar feedback in a clumpy galaxy at z 3.4

Journal
Date Issued
2021
Author(s)
Iani, E.
•
•
Vernet, J.
•
Richard, J.
•
Gronke, M.
•
Harrison, C. M.
•
Arrigoni-Battaia, F.
•
Rodighiero, G.
•
Burkert, A.
•
Behrendt, M.
•
Chen, Chian-Chou
•
Emsellem, E.
•
Fensch, J.
•
Hibon, P.
•
Hilker, M.
•
Le Floc'h, E.
•
Mainieri, V.
•
Swinbank, A. M.
•
Valentino, F.
•
•
Zwaan, M. A.
DOI
Abstract
Giant star-forming regions (clumps) are widespread features of galaxies at z ≍ 1-4. Theory predicts that they can play a crucial role in galaxy evolution, if they survive to stellar feedback for >50 Myr. Numerical simulations show that clumps' survival depends on the stellar feedback recipes that are adopted. Up to date, observational constraints on both clumps' outflows strength and gas removal time-scale are still uncertain. In this context, we study a line-emitting galaxy at redshift z ≃ 3.4 lensed by the foreground galaxy cluster Abell 2895. Four compact clumps with sizes ≲280 pc and representative of the low-mass end of clumps' mass distribution (stellar masses ≲2 × 108 M⊙) dominate the galaxy morphology. The clumps are likely forming stars in a starbursting mode and have a young stellar population (~10 Myr). The properties of the Lyman-α (Lyα) emission and nebular far-ultraviolet absorption lines indicate the presence of ejected material with global outflowing velocities of ~200-300 km s-1. Assuming that the detected outflows are the consequence of star formation feedback, we infer an average mass loading factor (η) for the clumps of ~1.8-2.4 consistent with results obtained from hydrodynamical simulations of clumpy galaxies that assume relatively strong stellar feedback. Assuming no gas inflows (semiclosed box model), the estimates of η suggest that the time-scale over which the outflows expel the molecular gas reservoir (≃7 × 108 M⊙) of the four detected low-mass clumps is ≲50 Myr.
Volume
507
Issue
3
Start page
3830
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2021MNRAS.507.3830I
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open.access
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