The unmixed debris of Gaia-Sausage/Enceladus in the form of a pair of halo stellar overdensities
- In the first billion years after its formation, the galaxy underwent several mergers with dwarf satellites of various masses. The debris of Gaia-Sausage/Enceladus (GSE), the galaxy responsible for the last significant merger of the Milky Way, dominates the inner halo and has been suggested to be the progenitor of both the Hercules-Aquila Cloud (HAC) and Virgo Overdensity (VOD). We combine SEGUE, APOGEE, Gaia, and StarHorse distances to characterize the chemodynamical properties and verify the link between HAC, VOD, and GSE. We find that the orbital eccentricity distributions of the stellar overdensities and GSE are comparable. We also find that they have similar, strongly peaked, metallicity distribution functions, reinforcing the hypothesis of common origin. Furthermore, we show that HAC and VOD are indistinguishable from the prototypical GSE population within all chemical-abundance spaces analyzed. All these evidences combined provide a clear demonstration that the GSE merger is the main progenitor of the stellar populations foundIn the first billion years after its formation, the galaxy underwent several mergers with dwarf satellites of various masses. The debris of Gaia-Sausage/Enceladus (GSE), the galaxy responsible for the last significant merger of the Milky Way, dominates the inner halo and has been suggested to be the progenitor of both the Hercules-Aquila Cloud (HAC) and Virgo Overdensity (VOD). We combine SEGUE, APOGEE, Gaia, and StarHorse distances to characterize the chemodynamical properties and verify the link between HAC, VOD, and GSE. We find that the orbital eccentricity distributions of the stellar overdensities and GSE are comparable. We also find that they have similar, strongly peaked, metallicity distribution functions, reinforcing the hypothesis of common origin. Furthermore, we show that HAC and VOD are indistinguishable from the prototypical GSE population within all chemical-abundance spaces analyzed. All these evidences combined provide a clear demonstration that the GSE merger is the main progenitor of the stellar populations found within these halo overdensities.…
Author details: | Hélio D. PerottoniORCiD, Guilherme LimbergORCiD, João A. S. AmaranteORCiD, Silvia RossiORCiD, Anna B. A. QueirozORCiDGND, Rafael M. SantucciORCiD, Angeles Pérez-VillegasORCiD, Cristina ChiappiniORCiD |
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DOI: | https://doi.org/10.3847/2041-8213/ac88d6 |
ISSN: | 2041-8205 |
ISSN: | 2041-8213 |
Title of parent work (English): | Astrophysical journal letters |
Publisher: | IOP Publishing |
Place of publishing: | Bristol |
Publication type: | Article |
Language: | English |
Date of first publication: | 2022/08/26 |
Publication year: | 2022 |
Release date: | 2024/06/21 |
Volume: | 936 |
Issue: | 1 |
Article number: | L2 |
Number of pages: | 7 |
Funding institution: | FAPESP [2015/50374-0, 2014/18100-4, 2018/21250-9, 2021/10429-0];; European Research Council (ERC) under the European Union [852839];; CAPES; CNPq [30667/2020-7]; DGAPA-PAPIIT [IA103122] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie |
Peer review: | Referiert |
Publishing method: | Open Access / Gold Open-Access |
License (German): | CC-BY - Namensnennung 4.0 International |