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ABSTRACT The element abundances of local group galaxies connect enrichment mechanisms to galactic properties and serve to contextualize the Milky Way’s abundance distributions. Individual stellar spectra in nearby galaxies can be extracted from integral field unit (IFU) data, and provide a means to take an abundance census of the local group. We introduce a programme that leverages $R=1800$, $$\mathrm{SNR}=15$$, IFU resolved spectra from the multi unit spectroscopic explorer . We deploy the data-driven modelling approach for labelling stellar spectra with stellar parameters and abundances, of The Cannon, on resolved stars in NGC 6822. We construct our model for The Cannon using $$\approx$$19 000 Milky Way lamost spectra with apogee labels. We report six inferred abundance labels (denoted $$\ell _\mathrm{X}$$), for 192 NGC 6822 disc stars, precise to $$\approx$$0.15 dex. We validate our generated spectral models provide a good fit to the data, including at individual atomic line features. We infer mean abundances of $$\ell _\mathrm{[Fe/H]} = -0.90 \pm 0.03$$, $$\ell _\mathrm{[Mg/Fe]} = -0.01 \pm 0.01$$, $$\ell _\mathrm{[Mn/Fe]} = -0.22 \pm 0.02$$, $$\ell _\mathrm{[Al/Fe]} = -0.33 \pm 0.03$$, $$\ell _\mathrm{[C/Fe]} =-0.43 \pm 0.03$$, $$\ell _\mathrm{[N/Fe]} =0.18 \pm 0.03$$. These abundance labels are similar to those of dwarf galaxies observed by apogee, and the lower enhancements for NGC 6822 compared to the Milky Way are consistent with expectations. This approach supports a new era in extragalactic archaeology of characterizing the local group enrichment diversity using low-resolution, low signal to noise ratio IFU resolved spectra. Furthermore, we conclude that it is feasible to build a model based on spectra observed with one instrument and apply it to spectra obtained with another.
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This content will become publicly available on May 1, 2026
Barium Abundances from the LAMOST Medium-Resolution Survey Stellar Spectra
Abstract Based on a template-matching method, we estimate the barium (Ba) abundances for stellar spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Medium-Resolution Spectroscopic Survey (MRS). The Ba abundances of 198,011 stars have been determined from MRS spectra with signal-to-noise ratios (S/N) > 40 combined with the stellar atmospheric parameters from the LAMOST Low-Resolution Spectroscopic Survey DR9 by the LAMOST Stellar Parameter Pipeline. The uncertainties in the Ba abundances from the LAMOST MRS spectra are less than 0.3 dex when S/N exceeds 40, which align closely with the results based on the high-resolution UVES spectra from the Gaia-ESO survey obtained by spectral synthesis. Further analysis of Ba abundances from repeated observations of the same stars reveals that random errors related to spectral quality remain below 0.3 dex at the same S/N, with a systematic overestimation for the low-S/N spectra. This extensive sample of stellar Ba abundances will enhance studies of thes-,i-, andr-processes, and deepen our understanding of the chemical-evolution history of the Milky Way.
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- Award ID(s):
- 1927130
- PAR ID:
- 10649103
- Publisher / Repository:
- IOPScience
- Date Published:
- Journal Name:
- The Astrophysical Journal Supplement Series
- Volume:
- 278
- Issue:
- 1
- ISSN:
- 0067-0049
- Page Range / eLocation ID:
- 23
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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