AAS 195th Meeting, January 2000
Session 62. Sgr A* and Milky Way
Oral, Thursday, January 13, 2000, 2:00-3:30pm, Regency VII

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[62.02] Keck/NIRSPEC Spectroscopy of Stars Near Sgr A*

D.F. Figer (STScI), E.E. Becklin, M. Morris, I.S. McLean (UCLA), J.R. Graham, A.M. Gilbert (UC Berkeley), J.E. Larkin (UCLA), N.A. Levenson (JHU), H.I. Teplitz (GSFC)

We present moderate (R approx 2,700) and high resolution (R approx 22,000) 2.0-2.4 um spectroscopy of the central 0.1 square arcseconds of the Galaxy obtained with NIRSPEC on the Keck II telescope. The composite spectra do not have any features attributable to the brightest stars in the central cluster, i.e. after background subtraction, WCO < 2 Å. This stringent limit, and previously reported photometry, lead us to conclude that the majority, if not all, of the stars are hotter than typical red giants, and are likely OB main sequence stars. In addition, we preview several other Galactic Center programs initiated with NIRSPEC which address the following topics: 1) the accelerations of stars around the central black hole, 2) the velocities of ionized gas in the central parsec, 3) the extent of the main sequence population and star formation history in the central parsec, 4) the mass magnitude relation and IMF in the Arches cluster, 5) the nature of the MIR sources in the central parsec and Quintuplet clusters, 6) the physical parameters of stellar atmosphere/winds of super luminous stars (Pistol Star), and 7) the metallicity in the GC as inferred from observations of red supergiants, red giants, and hot stars. We present a survey of these data, including a high resolution slit scan movie of the central parsec, and show how they can be used to vastly improve the current state of the art in the related science topics.


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