Due to its proximity , the Milky Way nuclear star cluster provides us with a wealth of data not available in other galactic nuclei .
In particular , with adaptive optics , we can observe the detailed properties of individual stars , which can offer insight into the origin and evolution of the cluster .
We summarize work on the central parsec of the Galactic center based on imaging and spectroscopic observations at the Keck and Gemini telescopes .
These observations include stellar positions in two dimension and the velocity in three dimensions .
Spectroscopic observations also enable measurements of the physical properties of individual stars , such as the spectral type and in some cases the effective temperature , metallicity , and surface gravity .
We present a review of our latest measurements of the density profiles and luminosity functions of the young and old stars in this region .
These observations show a complex stellar population with a young ( 4-6 Myr ) compact star cluster in the central 0.5 pc embedded in an older and much more massive nuclear star cluster .
Surprisingly , the old late-type giants do not show a cusp profile as long been expected from theoretical work .
The solution to the missing cusp problem may offer us insight into the dynamical evolution of the cluster .
Finally , we also discuss recent work on the metallicity of stars in this region and how they might be used to trace their origin .
The nuclear star cluster shows a large variation in metallicity ( [ M/Fe ] ) .
The majority of the stars have higher than solar metallicity , with about 6 % having [ M/Fe ] < -0.5 .
These observations indicate that the NSC was not built from the globular clusters that we see today .
The formation of the nuclear star cluster is more likely from the inward migration of gas originating in the disk of the Milky Way