Tools
Tools
Ciucă, I, Kawata, D, Ting, YS, Grand, RJJ, Miglio, A, Hayden, M, Baba, J, Fragkoudi, F, Monty, S, Buder, S and Freeman, K (2023) Chasing the impact of the Gaia-Sausage-Enceladus merger on the formation of the Milky Way thick disc. Monthly Notices of the Royal Astronomical Society: Letters, 528 (1). L122-L126. ISSN 1745-3925
|
Text
Chasing the impact of the Gaia-Sausage-Enceladus merger on the formation of the Milky Way thick disc.pdf - Published Version Available under License Creative Commons Attribution. Download (1MB) | Preview |
Abstract
We employ our Bayesian Machine Learning framework BINGO (Bayesian INference for Galactic archaeOlogy) to obtain high-quality stellar age estimates for 68 360 red giant and red clump stars present in the 17th data release of the Sloan Digital Sky Survey, the APOGEE-2 high-resolution spectroscopic survey. By examining the denoised age-metallicity relationship of the Galactic disc stars, we identify a drop in metallicity with an increase in [Mg/Fe] at an early epoch, followed by a chemical enrichment episode with increasing [Fe/H] and decreasing [Mg/Fe]. This result is congruent with the chemical evolution induced by an early-epoch gas-rich merger identified in the Milky Way-like zoom-in cosmological simulation Auriga. In the initial phase of the merger of Auriga 18 there is a drop in metallicity due to the merger diluting the metal content and an increase in the [Mg/Fe] of the primary galaxy. Our findings suggest that the last massive merger of our Galaxy, the Gaia-Sausage-Enceladus, was likely a significant gas-rich merger and induced a starburst, contributing to the chemical enrichment and building of the metal-rich part of the thick disc at an early epoch.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | 0201 Astronomical and Space Sciences |
| Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
| Divisions: | Astrophysics Research Institute |
| Publisher: | Oxford University Press (OUP) |
| SWORD Depositor: | A Symplectic |
| Date Deposited: | 23 Sep 2024 15:58 |
| Last Modified: | 23 Sep 2024 16:00 |
| DOI or ID number: | 10.1093/mnrasl/slad033 |
| URI: | https://researchonline.ljmu.ac.uk/id/eprint/24242 |
 |
View Item |