000008065 001__ 8065
000008065 005__ 20260313095606.0
000008065 0247_ $$2DOI$$a10.1051/0004-6361/202452784 
000008065 037__ $$aSCART-2026-0138
000008065 100__ $$aBrands, Sarah A.
000008065 245__ $$aX-Shooting ULLYSES: Massive stars at low metallicity: XII. Clumped winds of O-type (super)giants in the Large Magellanic Cloud
000008065 260__ $$c2025
000008065 520__ $$aContext. Mass loss governs the evolution of massive stars and shapes the stellar surroundings. To quantify the impact of the stellar winds, we need to know the exact mass-loss rates; however, empirical constraints on the rates are hampered by limited knowledge of their small-scale wind structure, also referred to as 'wind clumping'. Aims. We aim to improve empirical constraints on the mass loss of massive stars by investigating the clumping properties of their winds, in particular, the relation between stellar parameters and wind structure. Methods. We analysed the optical and ultraviolet spectra of 25 O-type giants and supergiants in the Large Magellanic Cloud, using the model atmosphere code FASTWIND and a genetic algorithm. We derived the stellar and wind parameters, including detailed clumping properties, such as the amount of clumping, the density of the interclump medium, velocity─porosity of the medium, and wind turbulence. Results. We obtained stellar and wind parameters for 24 of our sample stars and found that the winds are highly clumped, with an average clumping factor of <fcl> = 33 14, an interclump density factor of <fic> = 0.2 0.1, and moderate-to-strong velocity-porosity effects of <fvel> = 0.6 0.2. The scatter around the average values of the wind-structure parameters is large. With the exception of a significant, positive correlation between the interclump density factor and mass loss, we find no dependence of clumping parameters on the mass-loss rate or stellar properties. Conclusions. In the luminosity range we investigate here, the empirical and theoretical mass-loss rates both have a scatter of about 0.5 dex (or a factor 3). Within this uncertainty, the empirical rates and theoretical predictions are in agreement. The origin of the scatter of the empirically inferred mass-loss rates requires further investigation. It is possible that our description of wind clumping is still not sufficient to capture effects of the structured wind, which could contribute to the scatter.
000008065 594__ $$aNO
000008065 700__ $$aBacks, Frank
000008065 700__ $$ade Koter, Alex
000008065 700__ $$aPuls, Joachim
000008065 700__ $$aCrowther, Paul A. 
000008065 700__ $$aSana, Hugues
000008065 700__ $$aTramper, Frank
000008065 700__ $$aKaper, Lex
000008065 700__ $$aSundqvist, Jon O.
000008065 700__ $$aBestenlehner, Joachim M.  
000008065 700__ $$aDriessen, Florian A. 
000008065 700__ $$aErba, Christiana
000008065 700__ $$aHawcroft, Calum
000008065 700__ $$aHerrero, Artemio
000008065 700__ $$aJohn Hillier, D.
000008065 700__ $$aIgnace, Richard
000008065 700__ $$aLefever, Roel R.
000008065 700__ $$aDylan Kee, N.
000008065 700__ $$aKubátová, Brankica
000008065 700__ $$aMahy, Laurent 
000008065 700__ $$aMoffat, Anthony F. J.
000008065 700__ $$aNajarro, Francisco
000008065 700__ $$aPrinja, Raman K.
000008065 700__ $$aRamachandran, Varsha
000008065 700__ $$aSander, Andreas A. C.
000008065 700__ $$aVink, Jorick S. 
000008065 773__ $$c36$$nA54$$pAstronomy & Astrophysics$$y2025
000008065 8560_ $$flaurent.mahy@ksb-orb.be
000008065 8564_ $$s7419847$$uhttps://publi2-as.oma.be/record/8065/files/aa52784-24.pdf
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000008065 905__ $$apublished in
000008065 980__ $$aREFERD