Photospheric properties and fundamental parameters of M dwarfs

TL;DR

This study uses high-resolution H-band spectra to determine fundamental parameters of M dwarfs, improving understanding of their atmospheres and validating atmospheric models, which is crucial for stellar and galactic evolution studies.

Contribution

It provides a detailed spectroscopic analysis of M dwarfs using APOGEE data to derive their fundamental parameters and validate atmospheric models.

Findings

Accurate measurements of Teff, log g, and [Fe/H] for M dwarfs.

Validation of BT-settl atmospheric models against high-resolution spectra.

Insights into dust formation and metal depletion in M dwarf atmospheres.

Abstract

M dwarfs are an important source of information when studying and probing the lower end of the Hertzsprung-Russell (HR) diagram, down to the hydrogen-burning limit. Being the most numerous and oldest stars in the galaxy, they carry fundamental information on its chemical history. The presence of molecules in their atmospheres, along with various condensed species, complicates our understanding of their physical properties and thus makes the determination of their fundamental stellar parameters more challenging and difficult. The aim of this study is to perform a detailed spectroscopic analysis of the high-resolution H-band spectra of M dwarfs in order to determine their fundamental stellar parameters and to validate atmospheric models. The present study will also help us to understand various processes, including dust formation and depletion of metals onto dust grains in M dwarf atmospheres. The high spectral resolution also provides a unique opportunity to constrain other chemical and physical processes that occur in a cool atmosphere The high-resolution APOGEE spectra of M dwarfs, covering the entire H-band, provide a unique opportunity to measure their fundamental parameters. We have performed a detailed spectral synthesis by comparing these high-resolution H-band spectra to that of the most recent BT-settl model and have obtained fundamental parameters such as effective temperature, surface gravity, and metallicity (Teff, log g and [Fe/H]) respectively.