A comparative analysis of the chemical compositions of Gaia-Enceladus/Sausage and Milky Way satellites using APOGEE
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Fecha
2023-03
Profesor/a Guía
Facultad/escuela
Idioma
en
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Editor
Oxford University Press
Nombre de Curso
Licencia CC
CC BY 4.0 Attribution 4.0 International Deed
Licencia CC
https://creativecommons.org/licenses/by/4.0/
Resumen
We use data from the 17th data release of the Apache Point Observatory Galactic Evolution Experiment (APOGEE 2) to contrast the chemical composition of the recently discovered Gaia Enceladus/Sausage system (GE/S) to those of 10 Milky Way (MW) dwarf satellite galaxies: LMC, SMC, Boötes I, Carina, Draco, Fornax, Sagittarius, Sculptor, Sextans, and Ursa Minor. Our main focus is on the distributions of the stellar populations of those systems in the [Mg/Fe]-[Fe/H] and [Mg/Mn]-[Al/Fe] planes, which are commonly employed in the literature for chemical diagnosis and where dwarf galaxies can be distinguished from in situ populations. We show that, unlike MW satellites, a GE/S sample defined purely on the basis of orbital parameters falls almost entirely within the locus of 'accreted' stellar populations in chemical space, which is likely caused by an early quenching of star formation in GE/S. Due to a more protracted history of star formation, stars in the metal-rich end of the MW satellite populations are characterized by lower [Mg/Mn] than those of their GE/S counterparts. The chemical compositions of GE/S stars are consistent with a higher early star formation rate (SFR) than MW satellites of comparable and even higher mass, suggesting that star formation in the early universe was strongly influenced by other parameters in addition to mass. We find that the direction of the metallicity gradient in the [Mg/Mn]-[Al/Fe] plane of dwarf galaxies is an indicator of the early SFR of the system. © 2022 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
Notas
Indexación: Scopus
Palabras clave
Galaxies: Abundances, Galaxies: Dwarf, Galaxies: Local Group, Galaxies: Magellanic Clouds
Citación
Monthly Notices of the Royal Astronomical Society. Volume 519, Issue 3, Pages 3611 - 3622. 1 March 2023
DOI
10.1093/mnras/stac3543