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Profile picture Diane Feuillet

Diane Feuillet

Researcher

Profile picture Diane Feuillet

A comparative analysis of the chemical compositions of Gaia-Enceladus/Sausage and Milky Way satellites using APOGEE

Author

  • Laura Fernandes
  • Clinton C. Mason
  • Danny Horta
  • Ricardo P. Schiavon
  • Christian Hayes
  • Sten Hasselquist
  • Diane Feuillet
  • Rachael L. Beaton
  • Henrik Jönsson
  • Shobhit Kisku
  • Ivan Lacerna
  • Jianhui Lian
  • Dante Minniti
  • Sandro Villanova
Show all

Summary, in English

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.

Department/s

  • Lund Observatory - Has been reorganised
  • eSSENCE: The e-Science Collaboration

Publishing year

2023-03-01

Language

English

Pages

3611-3622

Publication/Series

Monthly Notices of the Royal Astronomical Society

Volume

519

Issue

3

Document type

Journal article

Publisher

Oxford University Press

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • galaxies: abundances
  • galaxies: dwarf
  • galaxies: Local Group
  • galaxies: Magellanic Clouds

Status

Published

ISBN/ISSN/Other

  • ISSN: 0035-8711