Chemical Analysis of the Brightest Star of the Cetus II Ultrafaint Dwarf Galaxy Candidate

We present a detailed chemical abundance analysis of the brightest star in the ultrafaint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra. For this star, DES J011740.53-173053, abundances or upper limits of 18 elements from carbon to europium are derived. Its chemica...

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Detalles Bibliográficos
Autores: Webber, K. B., Hansen, T. T., Marshall, J. L., Simon, J. D., Pace, A. B., Mutlu-Pakdil, B., Drlica-Wagner, A., Martínez-Vázquez, C. E., Aguena, M., Allam, S. S., Alves, O., Bertin, E., Brooks, D., Carnero Rosell, A., Carretero, J., da Costa, L. N., De Vicente, J., Doel, P., Ferrero, I., Friedel, D., Frieman, J., García-Bellido Capdevila, Juan, Giannini, G., Gruen, D., Gruendl, R. A., Hinton, S. R., Hollowood, D. L., Honscheid, Klaus, Kuehn, K., Mena-Fernández, J., Menanteau, F., Miquel, R., Ogando, R. L.C., Pereira, M. E.S., Pieres, A., Plazas Malagón, A. A., Sánchez, E., Santiago, B., Smith, J. Allyn, Smith, M., Suchyta, E., Tarle, Gregory, To, C., Weaverdyck, N., Yanny, B.
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/713419
Acceso en línea:http://hdl.handle.net/10486/713419
https://dx.doi.org/10.3847/1538-4357/ad0385
Access Level:acceso abierto
Palabra clave:Galaxies
stellar parameters
brightest star
Física
Descripción
Sumario:We present a detailed chemical abundance analysis of the brightest star in the ultrafaint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra. For this star, DES J011740.53-173053, abundances or upper limits of 18 elements from carbon to europium are derived. Its chemical abundances generally follow those of other UFD galaxy stars, with a slight enhancement of the α-elements (Mg, Si, and Ca) and low neutron-capture element (Sr, Ba, and Eu) abundances supporting the classification of Cetus II as a likely UFD. The star exhibits lower Sc, Ti, and V abundances than Milky Way (MW) halo stars with similar metallicity. This signature is consistent with yields from a supernova originating from a star with a mass of ∼11.2 M ⊙. In addition, the star has a potassium abundance of [K/Fe] = 0.81, which is somewhat higher than the K abundances of MW halo stars with similar metallicity, a signature that is also present in a number of UFD galaxies. A comparison including globular clusters and stellar stream stars suggests that high K is a specific characteristic of some UFD galaxy stars and can thus be used to help classify objects as UFD galaxies

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