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dc.contributor.authorNorris, John
dc.contributor.authorBessell, Michael
dc.contributor.authorYong, David
dc.contributor.authorChristlieb, Norbert
dc.contributor.authorBarklem, Paul
dc.contributor.authorAsplund, Martin
dc.contributor.authorMurphy, Michael
dc.contributor.authorBeers, Timothy
dc.contributor.authorFrebel, Anna
dc.contributor.authorRyan, Sean G.
dc.date.accessioned2013-08-05T10:33:15Z
dc.date.available2013-08-05T10:33:15Z
dc.date.issued2013-01
dc.identifier.citationNorris , J , Bessell , M , Yong , D , Christlieb , N , Barklem , P , Asplund , M , Murphy , M , Beers , T , Frebel , A & Ryan , S G 2013 , ' The Most Metal-poor Stars. I : Discovery, Data and Atmospheric Parameters ' , The Astrophysical Journal , vol. 762 , 25 . https://doi.org/10.1088/0004-637X/762/1/25
dc.identifier.issn0004-637X
dc.identifier.otherPURE: 2153263
dc.identifier.otherPURE UUID: 8fd652b6-3254-43ca-8523-1c9fcb7e931a
dc.identifier.otherScopus: 84871316047
dc.identifier.urihttp://hdl.handle.net/2299/11290
dc.description.abstractWe report the discovery of 34 stars in the Hamburg/ESO Survey for metal-poor stars and the Sloan Digital Sky Survey that have [Fe/H] <~ -3.0. Their median and minimum abundances are [Fe/H] = -3.1 and -4.1, respectively, while 10 stars have [Fe/H] < -3.5. High-resolution, high signal-to-noise spectroscopic data—equivalent widths and radial velocities—are presented for these stars, together with an additional four objects previously reported or currently being investigated elsewhere. We have determined the atmospheric parameters, effective temperature (T eff), and surface gravity (log g), which are critical in the determination of the chemical abundances and the evolutionary status of these stars. Three techniques were used to derive these parameters. Spectrophotometric fits to model atmosphere fluxes were used to derive T eff, log g, and an estimate of E(B - V); Hα, Hβ, and Hγ profile fitting to model atmosphere results provided the second determination of T eff and log g; and finally, we used an empirical T eff-calibrated Hδ index, for the third, independent T eff determination. The three values of T eff are in good agreement, although the profile fitting may yield systematically cooler T eff values, by ~100 K. This collective data set will be analyzed in future papers in the present series to utilize the most metal-poor stars as probes of conditions in the early universe.en
dc.language.isoeng
dc.relation.ispartofThe Astrophysical Journal
dc.rightsOpen
dc.subjectearly universe, Galaxy: formation, Galaxy: halo, stars: abundances, stars: fundamental parameters
dc.titleThe Most Metal-poor Stars. I : Discovery, Data and Atmospheric Parametersen
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.contributor.institutionScience & Technology Research Institute
dc.contributor.institutionCentre for Astrophysics Research
dc.description.statusPeer reviewed
dc.relation.schoolSchool of Physics, Astronomy and Mathematics
dc.description.versiontypeFinal Accepted Version
dcterms.dateAccepted2013-01
rioxxterms.versionAM
rioxxterms.versionofrecordhttps://doi.org/10.1088/0004-637X/762/1/25
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue
herts.rights.accesstypeOpen


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