Name/Affiliation: Elena Manjavacas (Max Planck Institut fuer Astronomie, Heidelberg)
Towards a complete brown dwarf binary fraction including spectroscopic binaries
The fraction of brown dwarfs binary systems is estimated to be about 20% for L and T spectral classes, nevertheless, due to selection methods, some close binaries (separation smaller than 0."1) and binaries with high excentricity will be missed. Allen et al. 2007 estimates the missing fraction at 6-7%. We used X-Shooter at VLT, to obtain high resolution spectra from 559.5 to 2480 nm of 22 brown dwarfs with peculiar spectra or different spectral type in the visible and near-infrared, which are potentially the best candidates to be close binaries. We compared our spectra with templates of well-classified spectra of mature and young brown dwarfs, as well as companions. Finally, we tested if the BT-Settl sythethic spectra 2010 and 2013 are able to reproduce our spectra in the optical and the near-infrared.