A Large Sample of Am Candidates from LAMOST Data Release 1

TL;DR

This paper identifies 3537 Am star candidates from LAMOST DR1 data using spectral line indices, providing a valuable, fainter extension to existing catalogs of chemically peculiar stars.

Contribution

It introduces an empirical method to select Am candidates from low-resolution spectra and compiles a large, faint sample for further research.

Findings

Identified 3537 Am candidates from over 30,000 stars.

Am candidates are generally fainter than those in previous catalogs.

Provided a publicly available list with 10 relevant parameters.

Abstract

We present a sample of metallic-line star (Am) candidates from the Large sky Area Multi-Object fiber Spectroscopic Telescope Data Release one (LAMOST DR1). According to the characteristic of under-abundance of calcium and overabundance of iron element of Am stars, we propose an empirical separation curve derived from line indices of Ca II K-line and iron lines we choose for low resolution spectra. 3537 Am candidates are ultimately selected from more than 30,000 stars which are classified as A-type or early-F stars by both LAMOST pipeline and visual inspection. Then we make some analysis on this sample and finally provide a list of these Am candidates with 10 relevant parameters. Comparing with other catalogues, Am candidates selected from LAMOST DR1 are much fainter on the whole. Obviously, our list is an important complementary to already known bright Am catalogues, and it offers valuable material for the research on this type of chemically peculiar stars.