Binary stars from long-term obs. of the Gal. center

This survey is based primarily on over a decade of adaptive optics-fed integral-field spectroscopy (R~4000), obtained as part of the Galactic Center Orbits Initiative at Keck Observatory, and it has a limiting K'-band magnitude of 15.8, which is at least 4mag deeper than previous spectroscopic searches for binaries at larger radii within the central nuclear star cluster.

From this primary data set, over 600 new radial velocities are extracted and reported, increasing by a factor of 3 the number of such measurements. We find no significant periodic signals in our sample of 28 stars, of which 16 are massive, young (main-sequence B) stars and 12 are low-mass, old (M and K giant) stars. Using Monte Carlo simulations, we derive upper limits on the intrinsic binary star fraction for the young star population at 47% (at 95% confidence) located ~20mpc from the black hole.