A new method based on Markov chains for deriving SB2 orbits directly
  from their spectra
  We present a new method to derive orbital elements of double-lined
spectroscopic binaries (SB2). The aim is to have accurate orbital parameters of
a selection of SB2 in order to prepare the exploitation of astrometric Gaia
observations. Combined with our results, they should allow one to measure the
mass of each star with a precision of better than 1%. The new method presented
here consists of using the spectra at all epochs simultaneously to derive the
orbital elements without templates. It is based on a Markov chain including a
new method for disentangling the spectra.
