2006/09/30 by I. Hunter, P. L. Dufton, S. J. Smartt +6 · 12 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Chemical composition #Effective temperature #Galaxy #Large Magellanic Cloud #Metallicity #Small Magellanic Cloud #Spectral line #Stars #Stellar classification #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20066148
published as Astron.Astrophys.466:277-300,2007 · A&A accepted. 32 pages, 14 figures reduced in quality. Replaced version updated with correct masses for LMC objects. Full quality version and online data available at http://star.pst.qub.ac.uk/~ih/
openalex publication_date 2006/10/04 · arxiv created 2006/11/20 · arxiv updated 2014/10/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present an analysis of high-resolution FLAMES spectra of approximately 50 early B-type stars in three young clusters at different metallicities, NGC 6611 in the Galaxy, N 11 in the Large Magellanic Cloud (LMC) and NGC 346 in the Small Magellanic Cloud (SMC). Using the tlusty non-LTE model atmospheres code, atmospheric parameters and photospheric abundances (C, N, O, Mg and Si) of each star have been determined. These results represent a significant improvement on the number of Magellanic Cloud B-type stars with detailed and homogeneous estimates of their atmospheric parameters and chemical compositions. The relationships between effective temperature and spectral type are discussed for all three metallicity regimes, with the effective temperature for a given spectral type increasing as one moves to a lower metallicity regime. Additionally the difficulties in estimating the microturbulent velocity and the anomalous values obtained, particularly in the lowest metallicity regime, are discussed. Our chemical composition estimates are compared with previous studies, both stellar and interstellar with, in general, encouraging agreement being found. Abundances in the Magellanic Clouds relative to the Galaxy are discussed and we also present our best estimates of the base-line chemical composition of the LMC and SMC as derived from B-type stars. Additionally we discuss the use of nitrogen as a probe of the evolutionary history of stars, investigating the roles of rotational mixing, mass-loss, blue loops and binarity on the observed nitrogen abundances and making comparisons with stellar evolutionary models where possible.