A signature of the donor star in the extra-galactic X-ray binary LMC X−2
A signature of the donor star in the extra-galactic X-ray binary LMC X−2
Two nights of phase-resolved medium-resolution Very Large Telescope spectroscopy of the extra-galactic low-mass X-ray binary LMC X−2 have revealed a 0.32 ± 0.02 d spectroscopic period in the radial velocity curve of the He iiλ4686 emission line that we interpret as the orbital period. However, similar to previous findings, this …