Zusammenfassung
We report the definite spectroscopic identification of 41 OB supergiants,
giants and main sequence stars in the central parsec of the Galaxy. Detection
of their absorption lines have become possible with the high spatial and
spectral resolution and sensitivity of the adaptive optics integral field
spectrometer SPIFFI/SINFONI on the ESO VLT. Several of these OB stars appear to
be helium and nitrogen rich. Almost all of the ~80 massive stars now known in
the central parsec (central arcsecond excluded) reside in one of two somewhat
thick (<|h|/R>~0.14) rotating disks. These stellar disks have fairly sharp
inner edges (R~1") and surface density profiles that scale as R^-2. We do not
detect any OB stars outside the central 0.5 pc. The majority of the stars in
the clockwise system appear to be on almost circular orbits, whereas most of
those in the `counter-clockwise' disk appear to be on eccentric orbits. Based
on its stellar surface density distribution and dynamics we propose that IRS
13E is an extremely dense cluster (core density > 3x10^8 sunmass/pc^3), which
has formed in the counter-clockwise disk. The stellar contents of both systems
are remarkably similar, indicating a common age of ~6+/-2 Myr. The K-band
luminosity function of the massive stars suggests a top-heavy mass function and
limits the total stellar mass contained in both disks to ~1.5x10^4 sunmass. Our
data strongly favor in situ star formation from dense gas accretion disks for
the two stellar disks. This conclusion is very clear for the clockwise disk and
highly plausible for the counter-clockwise system.
Nutzer