| Full text | |
| Author(s): |
Limberg, Guilherme
;
Souza, Stefano O.
;
Perez-Villegas, Angeles
;
Rossi, Silvia
;
Perottoni, Helio D.
;
Santucci, Rafael M.
Total Authors: 6
|
| Document type: | Journal article |
| Source: | ASTROPHYSICAL JOURNAL; v. 935, n. 2, p. 16-pg., 2022-08-01. |
| Abstract | |
We combine spectroscopic, photometric, and astrometric information from APOGEE data release 17 and Gaia early data release 3 to perform a self-consistent characterization of Gaia-Sausage/Enceladus (GSE), the remnant of the last major merger experienced by the Milky Way, considering stars and globular clusters (GCs) altogether. Our novel set of chemodynamical criteria to select genuine stars of GSE yields a metallicity distribution function with a median [Fe/H] of -1.22 and 0.23 dex dispersion. Stars from GSE present an excess of [Al/Fe] and [Mg/Mn] (also [Mg/Fe]) in comparison to surviving Milky Way dwarf satellites, which can be explained by differences in star formation efficiencies and timescales between these systems. However, stars from Sequoia, another proposed accreted halo substructure, essentially overlap the GSE footprint in all analyzed chemical-abundance spaces, but present lower metallicities. Among the probable GCs of GSE with APOGEE observations available, we find no evidence for atypical [Fe/H] spreads with the exception of omega Centauri (omega Cen). Under the assumption that omega Cen is a stripped nuclear star cluster, we estimate the stellar mass of its progenitor to be M-star approximate to 1.3 x 10(9) M-circle dot, well within literature expectations for GSE. This leads us to envision GSE as the best available candidate for the original host galaxy of omega Cen. We also take advantage of Gaia's photometry and APOGEE metallicities as priors to determine fundamental parameters for eight high-probability (>70%) GC members of GSE via statistical isochrone fitting. Finally, the newly determined ages and APOGEE [Fe/H] values are utilized to model the age-metallicity relation of GSE. (AU) | |
| FAPESP's process: | 15/50374-0 - Mosaic: the multi-object spectrograph for the ESO Extremely Large Telescope |
| Grantee: | Silvia Cristina Fernandes Rossi |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 14/18100-4 - Stellar populations in the Milky Way: bulge, halo, disk and star forming regions; instrumentation for high resolution spectroscopy |
| Grantee: | Beatriz Leonor Silveira Barbuy |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 18/22044-3 - Bulge globular clusters: relics of the early formation of the galaxy |
| Grantee: | Stefano Oliveira de Souza |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| FAPESP's process: | 21/10429-0 - The chemodynamical structure of the ancient galactic halo |
| Grantee: | Guilherme Limberg |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |