Spectral analysis of high resolution near-infrared spectra of ultra cool dwarfs

TL;DR

This paper analyzes high-resolution near-infrared spectra of ultra cool dwarfs, utilizing new and existing molecular line lists to model spectral features and assess the accuracy of molecular and atomic data.

Contribution

It introduces a spectral analysis method for ultra cool dwarfs using a new water vapour line list and evaluates the accuracy of FeH and CrH line lists in spectral modeling.

Findings

Good fit for Mn I line with reliable oscillator strength

FeH and water lines dominate observed features

Uncertainty in atomic line parameters limits spectral analysis

Abstract

We present an analysis of high resolution spectra in the J band of five ultra cool dwarfs from M6 to L0. A new ab initio water vapour line list and existing line lists of FeH and CrH were used for spectra modelling. We find a good fit for the Mn I 12899.76 A line. This feature is one of the few for which we have a reliable oscillator strength. Other atomic features are present but most of the observed features are FeH and water lines. While we are uncertain about the quality of many of the atomic line parameters, the FeH and CrH line lists predict a number of features which are not apparent in our observed spectra. We infer that the main limiting factor in our spectral analysis is the FeH and CrH molecular spectra.