Abstract

Contributed Talk - Splinter LowMet

Friday, 13 September 2024, 14:30   (S23)

Metal-poor massive OB stars in the Magellanic Bridge

Elisa Schösser, Varsha Ramachandran, Andreas Sander
ZAH/ ARI, Universität Heidelberg

Until recently, massive stars with metallicities lower than those in the Small Magellanic Cloud (SMC) were only known in compact dwarf galaxies, with observations in such distant locations suffering from limited signal-to-noise ratios and spatial resolution. We discovered three O stars and several early B-type stars in the Magellanic Bridge - a stream of gas and stars connecting the two Magellanic Clouds. Using newly acquired HST UV spectra combined with archival optical spectra, we measured for the first time the inherent iron abundances and characterize the stellar and wind properties of these stars with detailed, non-LTE quantitative spectroscopy. Thereby, we discovered the first nearby massive O stars with a severely sub-SMC metallicity, reaching as low as 0.06 Zsol. Our study provides crucial observational constraints on the mass loss rates, feedback and evolution of massive stars in metal poor environments.