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dc.contributor.authorSpitoni, Emanuele
dc.contributor.authorVincenzo, F.
dc.contributor.authorMatteucci, Francesca
dc.contributor.authorRomano, D.
dc.date.accessioned2017-08-07T15:27:46Z
dc.date.available2017-08-07T15:27:46Z
dc.date.issued2016-05-21
dc.identifier.citationSpitoni , E , Vincenzo , F , Matteucci , F & Romano , D 2016 , ' Are ancient dwarf satellites the building blocks of the Galactic halo? ' , Monthly Notices of the Royal Astronomical Society , vol. 458 , no. 3 , pp. 2541-2552 . https://doi.org/10.1093/mnras/stw519
dc.identifier.issn0035-8711
dc.identifier.otherPURE: 11927471
dc.identifier.otherPURE UUID: 598ab7a7-37ef-4709-b2e4-4711414590b8
dc.identifier.otherArXiv: http://arxiv.org/abs/1603.00344v1
dc.identifier.otherScopus: 84964767243
dc.identifier.urihttp://hdl.handle.net/2299/19164
dc.descriptionThis article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. ©: 2016 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
dc.description.abstractAccording to the current cosmological cold dark matter paradigm, the Galactic halo could have been the result of the assemblage of smaller structures. Here we explore the hypothesis that the classical and ultra-faint dwarf spheroidal satellites of the Milky Way have been the building blocks of the Galactic halo by comparing their [α/Fe] and [Ba/Fe] versus [Fe/H] patterns with the ones observed in Galactic halo stars. The α elements deviate substantially from the observed abundances in the Galactic halo stars for [Fe/H] values larger than −2 dex, while they overlap for lower metallicities. On the other hand, for the [Ba/Fe] ratio, the discrepancy is extended at all [Fe/H] values, suggesting that the majority of stars in the halo are likely to have been formed in situ. Therefore, we suggest that [Ba/Fe] ratios are a better diagnostic than [α/Fe] ratios. Moreover, for the first time we consider the effects of an enriched infall of gas with the same chemical abundances as the matter ejected and/or stripped from dwarf satellites of the Milky Way on the chemical evolution of the Galactic halo. We find that the resulting chemical abundances of the halo stars depend on the assumed infall time-scale, and the presence of a threshold in the gas for star formation. In particular, in models with an infall time-scale for the halo around 0.8 Gyr coupled with a threshold in the surface gas density for the star formation (4 M pc−2), and the enriched infall from dwarf spheroidal satellites, the first halo stars formed show [Fe/H]>−2.4 dex. In this case, to explain [α/Fe] data for stars with [Fe/H]<−2.4 dex, we need stars formed in dSph systems.en
dc.format.extent12
dc.language.isoeng
dc.relation.ispartofMonthly Notices of the Royal Astronomical Society
dc.rights/dk/atira/pure/core/openaccesspermission/open
dc.subjectISM: abundances
dc.subjectGalaxy: abundances
dc.subjectGalaxy: evolution
dc.subjectGalaxy: halo
dc.titleAre ancient dwarf satellites the building blocks of the Galactic halo?en
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.description.statusPeer reviewed
dc.relation.schoolSchool of Physics, Astronomy and Mathematics
dc.description.versiontypeFinal Published version
dcterms.dateAccepted2016-02-29
rioxxterms.versionAM
rioxxterms.versionVoR
rioxxterms.versionofrecordhttps://doi.org/10.1093/mnras/stw519
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue
herts.rights.accesstypeopenAccess


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