ACACIAS I

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, 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 approximate to 19 000 Milky Way LAMOST spectra with APOGEE labels. We report six inferred abundance labels (denoted (l(x)), for 192 NGC 6822 disc stars, precise to 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 l([Fe/H]) /= -0.90 +/- 0.03, l([Mg/Fe])=-0.01 +/- 0.01, l([Mn/Fe])=-0.22 +/- 0.02, l([Al/Fe])=-0.33 +/- 0.03, l[c/Fe]= -0.43 +/- 0.03, l([N/Fe])=0.18 +/- 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. Show more