Chemical abundance analysis of three α-poor, metal-poor stars in the ultrafaint dwarf galaxy Horologium I
dc.contributor.author | Nagasawa, Daniel Q. | pt_BR |
dc.contributor.author | Santiago, Basilio Xavier | pt_BR |
dc.contributor.author | Yanny, Brian | pt_BR |
dc.date.accessioned | 2018-05-17T02:26:15Z | pt_BR |
dc.date.issued | 2018 | pt_BR |
dc.identifier.issn | 0004-637X | pt_BR |
dc.identifier.uri | http://hdl.handle.net/10183/178349 | pt_BR |
dc.description.abstract | We present chemical abundance measurements of three stars in the ultrafaint dwarf galaxy Horologium I, a Milky Way satellite discovered by the Dark Energy Survey. Using high-resolution spectroscopic observations, we measure the metallicity of the three stars, as well as abundance ratios of several α-elements, iron-peak elements, and neutron-capture elements. The abundance pattern is relatively consistent among all three stars, which have a low average metallicity of [Fe/H]∼−2.6 and are not α-enhanced ([α/Fe]∼0.0). This result is unexpected when compared to other low-metallicity stars in the Galactic halo and other ultrafaint dwarfs and suggests the possibility of a different mechanism for the enrichment of Hor I compared to other satellites. We discuss possible scenarios that could lead to this observed nucleosynthetic signature, including extended star formation, enrichment by a Population III supernova, and or an association with the Large Magellanic Cloud. | en |
dc.format.mimetype | application/pdf | pt_BR |
dc.language.iso | eng | pt_BR |
dc.relation.ispartof | The astrophysical journal. Bristol. Vol. 852, no. 2 (Jan. 2018), 99, 16 p. | pt_BR |
dc.rights | Open Access | en |
dc.subject | Galaxies: abundances | en |
dc.subject | Galáxias | pt_BR |
dc.subject | Composicao estelar | pt_BR |
dc.subject | Galaxies: dwarf | en |
dc.subject | Stars: abundances | en |
dc.subject | Metalicidade | pt_BR |
dc.subject | Nucleosíntese | pt_BR |
dc.subject | Stars: chemically peculiar | en |
dc.subject | Grande Nuvem de Magalhães | pt_BR |
dc.subject | Supporting material: machine-readable table | en |
dc.title | Chemical abundance analysis of three α-poor, metal-poor stars in the ultrafaint dwarf galaxy Horologium I | pt_BR |
dc.type | Artigo de periódico | pt_BR |
dc.identifier.nrb | 001061780 | pt_BR |
dc.type.origin | Estrangeiro | pt_BR |
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