M dwarf Stars - The By-Product of X-Ray Selected AGN Candidates

TL;DR

This paper characterizes X-ray loud M dwarfs, identifying their spectral types, metallicity classes, and distribution patterns, which are important for understanding their contamination in quasar surveys.

Contribution

It provides the first low dispersion spectra for 16 M dwarfs and analyzes their metallicity and distribution, aiding in the identification of X-ray active M dwarfs in surveys.

Findings

Spectral types and distances of 22 M dwarfs determined.

Metallicity classes distinguished using {zet}TiO/CaH parameter.

Distribution patterns in X-ray to bolometric luminosity ratios analyzed.

Abstract

X-ray loud M dwarfs are a major source of by-product (contamination) in the X-ray band of the multiwavelength quasar survey (MWQS). As a by-product, the low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16 sources are taken for the first time. The spectral types and distance of the sample are given based on spectral indices CaH2, CaH3, and TiO5. The parameter {\zeta}TiO/CaH is calculated to make the metallicity class separation among dwarfs, subdwarfs and extreme subdwarfs. We also discuss the distributions in the diagrams of Log(Lx/Lbol) versus spectral type and infrared colors.