Stellar feedback in a clumpy galaxy at z similar to 3.4

Iani, E.; Zanella, A.; 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.; Vanzella, E. und Zwaan, M. A. (2021): Stellar feedback in a clumpy galaxy at z similar to 3.4. In: Monthly Notices of the Royal Astronomical Society, Bd. 507, Nr. 3: S. 3830-3848

Abstract

Giant star-forming regions (clumps) are widespread features of galaxies at z approximate to 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 similar or equal to 3.4 lensed by the foreground galaxy cluster Abell 2895. Four compact clumps with sizes less than or similar to 280 pc and representative of the low-mass end of clumps' mass distribution (stellar masses less than or similar to 2 x 10(8) M-circle dot) dominate the galaxy morphology. The clumps are likely forming stars in a starbursting mode and have a young stellar population (similar to 10 Myr). The properties of the Lyman-alpha (Ly alpha) emission and nebular far-ultraviolet absorption lines indicate the presence of ejected material with global outflowing velocities of similar to 200-300 km s(-1). Assuming that the detected outflows are the consequence of star formation feedback, we infer an average mass loading factor (eta) for the clumps of similar to 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 n suggest that the time-scale over which the outflows expel the molecular gas reservoir (similar or equal to 7 x 10(8 )M(circle dot)) of the four detected low-mass clumps is less than or similar to 50 Myr.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-8711
• Sprache: Englisch