Sulphur and iron abundances in halo stars

Simple item page
dc.creatorNissen, P. E.
dc.creatorChen, Y. Q.
dc.creatorAsplund, M.
dc.creatorPettini, M.
dc.date2002-07-08
dc.date.accessioned2026-07-07T02:04:12Z
dc.date.available2026-07-07T02:04:12Z
dc.descriptionFrom equivalent widths of the SI lines at 8694 A, Israelian & Rebolo (2001) and Takada-Hidai et al. (2002) have derived a surprisingly high sulphur-to-iron ratio ([S/Fe] = 0.5 to 0.7) in six halo stars with [Fe/H] ~ -2.0 suggesting perhaps that hypernovae made a significant contribution to the formation of elements in the early Galaxy. To investigate this problem we have used high-resolution spectra obtained with the ESO VLT/UVES spectrograph to determine the S/Fe ratio in 19 main-sequence and subgiant stars ranging in [Fe/H] from -3.2 to -0.7. The sulphur abundances are determined from SI lines at 8694 A and 9212 - 9237 A, and the iron abundances from about 20 FeII lines. S/Fe ratios as derived from 1D model atmospheres are presented and possible 3D effects are discussed. The initial results from our survey do not confirm the high values of [S/Fe] quoted above; instead we find that the ratio [S/Fe] remains constant at about 0.35 dex for metallicities -3 < [Fe/H] -1.
dc.description10 pages, 4 figures, 2 tables. To appear in proceedings of IAU Symp. 210, "Modelling of Stellar Atmospheres", ASP Conference Series, 2002, Eds. N. Piskunov, W.W. Weiss and D.F. Gray
dc.identifierhttps://arxiv.org/abs/astro-ph/0207163
dc.identifierhttp://arxiv.org/abs/astro-ph/0207163
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/4664
dc.subjectAstrophysics
dc.titleSulphur and iron abundances in halo stars
dc.typetext

Files

Collections

arXiv