A high resolution spectral atlas of brown dwarfs

TL;DR

This paper provides a high-resolution spectral atlas of brown dwarfs, enabling detailed analysis of ultra-cool atmospheres and comparison with atmospheric models to identify both successes and discrepancies in current understanding.

Contribution

It offers the first high-resolution optical spectral atlas of brown dwarfs, covering spectral details from Hα to 1 μm and comparing observations with atmospheric models.

Findings

Molecular features from VO and CaH are well modeled.

Atomic features from Cs and Rb are well modeled.

Discrepancies exist in TiO, CrH, water, Na, and K features.

Abstract

We present a UVES/VLT high resolution atlas of three L dwarfs and one T dwarf system, spectral classes at which most of the objects are brown dwarfs. Our atlas covers the optical region from H$\alpha$ up to the near infrared at 1 $\mu$m. We present spectral details of ultra-cool atmospheres at very high resolution ($R \sim 33 000$) and compare the spectra to model calculations. Our comparison shows that molecular features from VO and CaH, and atomic features from Cs and Rb are reasonably well fit by current models. On the other hand, features due to TiO, CrH, and water, and atomic Na and K reveal large discrepancies between model calculations and our observations.