Searching for r-process-enhanced stars in the LAMOST Survey I: The Method

TL;DR

This paper introduces a new method to identify r-process-enhanced stars in the LAMOST survey by matching observed spectra to synthetic templates around the Eu II line, resulting in a sample of 13 candidates for further study.

Contribution

The paper presents a novel spectral matching technique to efficiently find r-process-enhanced star candidates in medium-resolution spectroscopic data.

Findings

Identified 13 metal-poor r-process-enhanced star candidates from LAMOST data.

Developed a spectral matching method around Eu II line at 6645.1 Å.

Outlined plans for extending the method to larger samples and other spectral lines.

Abstract

The abundance patterns of $r$-process-enhanced stars contain key information required to constrain the astrophysical site(s) of $r$-process nucleosynthesis, and to deepen our understanding of the chemical evolution of our Galaxy. In order to expand the sample of known $r$-process-enhanced stars, we have developed a method to search for candidates in the LAMOST medium-resolution ($R \sim 7500$) spectroscopic survey by matching the observed spectra to synthetic templates around the Eu II line at 6645.1 AA. We obtain a sample of 13 metal-poor ($-2.35<{\rm [Fe/H]}<-0.91$) candidates from 12,209 unique stars with 32,774 medium-resolution spectra. These candidates will be further studied by high-resolution follow-up observations in the near future. Extensions of this effort to include larger samples of stars, in particular at lower metallicity, using the strength of the Ba II line at 6496.9 AA, are described.