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dc.contributor.authorReindl, Nicolept_BR
dc.contributor.authorRauch, Thomaspt_BR
dc.contributor.authorWerner, Klauspt_BR
dc.contributor.authorKepler, Souza Oliveirapt_BR
dc.contributor.authorGänsicke, Borispt_BR
dc.contributor.authorFusillo, Nicola Pietro Gentilept_BR
dc.date.accessioned2015-09-18T01:58:20Zpt_BR
dc.date.issued2014pt_BR
dc.identifier.issn0004-6361pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/126954pt_BR
dc.description.abstractWe report on the identification of 22 new cool DO-type white dwarfs (WDs) detected in data release 10 (DR10) of the Sloan Digital Sky Survey (SDSS). Among them, we found one more member of the so-called hot-wind DO WDs, which show ultrahigh excitation absorption lines. Our non-LTE model atmosphere analyses of these objects and two not previously analyzed hot-wind DO WDs, revealed effective temperatures and gravities in the ranges Teff =45−80 kK and log g=7.50−8.75. In eight of the spectra we found traces of C (0.001−0.01, by mass). Two of these are the coolest DO WDs ever discovered that still show a considerable amount of C in their atmospheres. This is in strong contradiction with diffusion calculations, and probably, similar to what is proposed for DBWDs, a weak mass-loss is present in DO WDs. One object is the most massive DO WD discovered so far with a mass of 1.07 M if it is an ONe-WD or 1.09 M if it is a CO-WD. We furthermore present the mass distribution of all known hot non-DA (pre-) WDs and derive the hot DA to non-DA ratio for the SDSS DR7 spectroscopic sample. The mass distribution of DO WDs beyond the wind limit strongly deviates from the mass distribution of the objects before the wind limit. We address this phenomenon by applying different evolutionary input channels. We argue that the DO WD channel may be fed by about 13% by post-extreme-horizontal branch stars and that PG1159 stars and O(He) stars may contribute in a similar extent to the non-DA WD channel.en
dc.format.mimetypeapplication/pdfpt_BR
dc.language.isoengpt_BR
dc.relation.ispartofAstronomy and astrophysics. Les Ulis. Vol. 572 (Dec. 2014), A117, 12 p.pt_BR
dc.rightsOpen Accessen
dc.subjectAtmosferas estelarespt_BR
dc.subjectStars: abundancesen
dc.subjectStars: evolutionen
dc.subjectEvolucao estelarpt_BR
dc.subjectEstrelas gigantespt_BR
dc.subjectStars: AGB and post-AGBen
dc.subjectWhite dwarfsen
dc.subjectMapeamentos astronômicospt_BR
dc.subjectAnãs brancaspt_BR
dc.subjectDifusãopt_BR
dc.titleAnalysis of cool DO-type white dwarfs from the Sloan Digital Sky Survey data release 10pt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb000972447pt_BR
dc.type.originEstrangeiropt_BR


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