Stellar feedback in a clumpy galaxy at z ∼ 3.4

Iani, E; Zanella, A; Vernet, J; Richard, J; Gronke, M; Harrison, CM; 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, AM; Valentino, F; Vanzella, E; Zwaan, MA

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.

Citation

Iani, E., Zanella, A., Vernet, J., Richard, J., Gronke, M., Harrison, C., …Zwaan, M. (2021). Stellar feedback in a clumpy galaxy at z ∼ 3.4. Monthly Notices of the Royal Astronomical Society, 507(3), 3830-3848. https://doi.org/10.1093/mnras/stab2376

• Journal Article Type: Article
• Acceptance Date: Jul 27, 2021
• Online Publication Date: Aug 3, 2021
• Publication Date: 2021-11
• Deposit Date: Dec 7, 2021
• Publicly Available Date: Dec 7, 2021
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 507
• Issue: 3
• Pages: 3830-3848
• DOI: https://doi.org/10.1093/mnras/stab2376