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dc.contributor.authorGeier, S.
dc.contributor.authorHeber, U.
dc.contributor.authorNapiwotzki, R.
dc.date.accessioned2008-10-03T09:29:40Z
dc.date.available2008-10-03T09:29:40Z
dc.date.issued2008
dc.identifier.citationGeier , S , Heber , U & Napiwotzki , R 2008 , Metal Abundances of Subdwarf B Stars from SPY - a Pattern Emerges . in In: Hot Subdwarf Stars and Related Objects - ASP Conf Series 392 . Astronomical Society of the Pacific , pp. 159-162 .
dc.identifier.isbn978-1-58381-654-7
dc.identifier.isbn978-1-58381-655-4
dc.identifier.otherPURE: 176475
dc.identifier.otherPURE UUID: 97672fde-aca9-4ecd-9942-b624e5b03826
dc.identifier.otherdspace: 2299/2427
dc.identifier.urihttp://hdl.handle.net/2299/2427
dc.descriptionOriginal paper can be found at: http://astrosociety.org/pubs/cs/381.html Copyright ASP
dc.description.abstractThe formation of sdBs is still puzzling, as is the chemical compo- sition of their atmospheres. While helium and other light elements are depleted relative to solar values, heavy elements are highly enriched. Diffusion processes in the hot, radiative atmosphere of these stars are the most likely explanation. Although several attempts were made, it was not yet possible to model all the observed features of sdB atmospheres. A setback of most prior studies was the small sample size. We present a detailed abundance analysis of 68 sdBs. From high resolution spectra obtained with the VLT/UVES instrument in the course of the ESO Supernova Progenitor Survey (SPY) we measured elemental abundances of up to 24 different ions per star. A general trend of enrichment was found with increasing temperature for most of the heavier elements. The lighter elements like carbon, oxygen and nitrogen are depleted irrespective of the temperature. Although there is considerable scatter from one star to another, the general abundance patterns in most sdBs are similar. An interplay between gravitational settling, radiative levitation and weak winds is most likely respon- sible. About 6% of the analysed stars show an enrichment in carbon and helium which cannot be explained in the framework of diffusion alone. Nuclear pro- cessed material must have been transported to the surface. The late hot-flasher scenario may provide a possible explanation for this effect.en
dc.language.isoeng
dc.publisherAstronomical Society of the Pacific
dc.relation.ispartofIn: Hot Subdwarf Stars and Related Objects - ASP Conf Series 392
dc.titleMetal Abundances of Subdwarf B Stars from SPY - a Pattern Emergesen
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
rioxxterms.typeOther
herts.preservation.rarelyaccessedtrue


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