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arXiv · 2009.03920

An unsupervised method for identifying $X$-enriched stars directly from spectra: Li in LAMOST

Adam Wheeler·Melissa Ness·David W. Hogg
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Abstract

Stars with peculiar element abundances are important markers of chemical enrichment mechanisms. We present a simple method, tangent space projection (TSP), for the detection of $X$-enriched stars, for arbitrary elements $X$, even from blended lines. Our method does not require stellar labels, but instead directly estimates the counterfactual unrenriched spectrum from other unlabelled spectra. As a case study, we apply this method to the $6708~$\AA{} Li doublet in LAMOST DR5, identifying 8,428 Li-enriched stars seamlessly across evolutionary state. We comment on the explanation for Li-enrichement for different subpopulations, including planet accretion, nonstandard mixing, and youth.

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Adam Wheeler, Melissa Ness, David W. Hogg. 2020-09-08. An unsupervised method for identifying $X$-enriched stars directly from spectra: Li in LAMOST. https://doi.org/10.3847/1538-4357/abd544

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