Spectroscopic binaries from LAMOST MRS. I.

The training set consists of a large set of mock spectra of single stars and binaries synthesized based on the MIST stellar evolutionary model and ATLAS9 atmospheric model. Our model reaches a novel theoretic false-positive rate by adding a proper penalty on the negative sample (e.g., 0.12% and 0.16% for the blue/red arm when the penalty parameter {Lambda}=16).

Tests show that the performance is as expected and favors FGK-type main-sequence (MS) binaries with high mass ratio (q>=0.7) and large radial velocity separation ({Delta}v>=50km/s). Although the real false-positive rate cannot be estimated reliably, validating on eclipsing binaries identified from Kepler light curves indicates that our model predicts low binary probabilities at eclipsing phases (0, 0.5, and 1.0) as expected.