A high resolution spectral atlas of brown dwarfs*
Universität Göttingen, Institut für Astrophysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany e-mail: [Ansgar.Reiners;derek]@astro.physik.uni-goettingen.de
2 Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany
3 Centre de Recherche Astrophysique de Lyon, UMR 5574: CNRS, Université de Lyon, École Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France
Accepted: 8 July 2007
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 Hα up to the near infrared at 1 μm. We present spectral details of ultra-cool atmospheres at very high resolution () 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.
Key words: line: identification / stars: low-mass, brown dwarfs / stars: atmospheres
© ESO, 2007