MK-like spectral classification for hot subdwarf stars with LAMOST spectra

TL;DR

This paper develops an MK-like spectral classification system for 1224 hot subdwarf stars using LAMOST DR9 spectra, categorizing them based on spectral line features and relating these to atmospheric parameters.

Contribution

It introduces a new spectral classification scheme for hot subdwarfs based on low-resolution spectra and standard line comparisons, expanding classification methods for these stars.

Findings

Stars categorized into four spectral groups: He-normal, He-weak, He-strong C, He-strong.

Relationships established between spectral classifications and atmospheric parameters.

Spectral line characteristics effectively used for classification and parameter estimation.

Abstract

An MK-like spectral classification has been conducted for 1224 hot subdwarf stars with LAMOST DR9 low-resolution spectra. The whole sample was divided into four categories according to the spectral line characteristics: He-normal, He-weak, He-strong C and He-strong. Each selected spectrum was assigned a spectral class, a luminosity class and an helium class by comparing the line depth and width with standard spectra selected in LAMOST. Relationships between atmospheric parameters and spectral classification were also presented.