Observational Evidence for a Compact Dark Mass at the Galactic Center
Chapter in Spiral Galaxies in the Near-IR, Springer Nature (1996) 117-123
The nature of nuclear starbursts: M82
Chapter in Spiral Galaxies in the Near-IR, Springer Nature (1996) 328-330
The stellar cluster at the center of the Galaxy
ASTR SOC P 98 (1996) 386-387
The nuclear cluster of the milky way: Star formation and velocity dispersion in the central 0.5 parsec
Astrophysical Journal 447:2 (1995) L95-L99
Abstract:
We report the first results of an extensive new study of the Galactic center stellar cluster. The central parsec is powered by a cluster of about two dozen luminous and helium-rich blue supergiants/Wolf-Rayet stars (Teff i 20,000-30,000 K) with ZAMS masses up to -100 MQ. The most likely scenario for the formation of the massive stars is a small star formation burst between 3 X 106 and 7 X 106 years ago. In this scenario the Galactic center is presently in a short-lived, post-main-sequence 鈥渨ind phase.鈥 In addition, there is evidence for another star formation event about 108 years ago, as well as for recently formed massive stars that may have been transported into the central core along with orbiting gas streamers. The radial velocity dispersion of 35 early- and late-type stars with distances of 1"-12" from Sgr A* is 154 卤 19 km s-1. Our new results strongly favor the existence of a central dark mass of -3 X 106 M鈯 (density > 108.5 M鈯 pc-3, M/L > 10 M鈯/L鈯) within 0.14 pc of the dynamic center. 漏 1995 The American Astronomical Society.3D - A new generation imaging spectrometer
P SOC PHOTO-OPT INS 2475 (1995) 172-183