As part of our search for young M dwarfs within 25 pc , we acquired high-resolution spectra of 185 low-mass stars compiled by the NStars project that have strong X-ray emission .
By cross-correlating these spectra with radial velocity standard stars , we are sensitive to finding multi-lined spectroscopic binaries .
We find a low-mass spectroscopic binary fraction of 16 % consisting of 27 SB2s , 2 SB3s and 1 SB4 , increasing the number of known low-mass SBs by 50 % and proving that strong X-ray emission is an extremely efficient way to find M-dwarf SBs .
WASP photometry of 23 of these systems revealed two low-mass EBs , bringing the count of known M dwarf EBs to 15 .
BD -22 5866 , the SB4 , is fully described in ( ) and CCDM J04404+3127 B consists of a two mid-M stars orbiting each other every 2.048 days .
WASP also provided rotation periods for 12 systems , and in the cases where the synchronization time scales are short , we used P _ { rot } to determine the true orbital parameters .
For those with no P _ { rot } , we use differential radial velocities to set upper limits on orbital periods and semi-major axes .
More than half of our sample has near-equal-mass components ( q > 0.8 ) .
This is expected since our sample is biased towards tight orbits where saturated X-ray emission is due to tidal spin-up rather than stellar youth .
Increasing the samples of M dwarf SBs and EBs is extremely valuable in setting constraints on current theories of stellar multiplicity and evolution scenarios for low-mass multiple systems .