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Super star clusters in the Galactic Center as revealed by HST-NICMOS

Published online by Cambridge University Press:  25 May 2016

Donald F. Figer
Affiliation:
Department of Physics & Astronomy, University of California, Los Angeles, CA 90095-1562, USA
Sungsoo S. Kim
Affiliation:
Korea Advanced Institute of Science and Technology, Department of Physics, Space Science Laboratory, Daejon, 305-701, Korea
Mark Morris
Affiliation:
Department of Physics & Astronomy, University of California, Los Angeles, CA 90095-1562, USA
Eugene Serabyn
Affiliation:
Jet Propulsion Laboratory, 171–113, 4800 Oak Grove Drive, Pasadena, CA 91109, USA

Abstract

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The three massive clusters in the Galactic Center are not only the most massive young clusters in the Galaxy, but they harbor more Wolf-Rayet stars than any other starburst region in the Local Group. An understanding of their stellar content will be valuable for extending models to starburst regions in other galaxies. We present HST-NICMOS images, luminosity functions, and color-magnitude diagrams of two of these: the Quintuplet and Arches clusters. The images allow the detection of stars over 6 magnitudes fainter than ever before and reveal previously undetected multiple star systems. For the first time, we clearly identify the main sequence in the Quintuplet cluster, and we extend earlier detections of the main sequence in the Arches cluster to Minitial < 10 M. We estimate that the Arches cluster has an initial mass function slope which is greater than the Salpeter value. Given their stellar content, the Galactic Center clusters provide both the best nearby examples of super star clusters and the best nearby locale in which to investigate WR phenomena in starburst galaxies and galactic nuclei. We discuss the content of the Galactic Center clusters, with a particular emphasis on how they compare to other massive clusters of the local group. We expect that many of the massive stars in the Galactic Center will soon evolve to become WR stars, and eventually become supernovae at a rate of ∼ 1 per 20 000 years for the next several Myr. We note that our preliminary N-body simulations suggest that such dense clusters are short-lived in the strong tidal field of the Galactic Center, consistent with the fact that no older dense clusters are seen in the central 50 pc. This implies a star formation rate of 5(10−3) M yr−1 in the Galactic Center.

Type
Part 4. Wolf-Rayet stars and other hot massive stars in the Galactic Center and in Local Group giant H II regions (individual stars)
Copyright
Copyright © Astronomical Society of the Pacific 1999 

References

Cotera, A.S., Erickson, E.F., Colgan, S.W.J., Simpson, J.P., Allen, D.A., Burton, M.G. 1996, ApJ 461, 750 Google Scholar
Cotera, A.S., Simpson, J.P., Erickson, E.F., Colgan, S.W.J., Burton, M.G., Allen, D.A. 1999, ApJ 510, 747 Google Scholar
Figer, D.F. 1995, PhD Thesis, University of California, Los Angeles Google Scholar
Figer, D.F., McLean, I. S., & Morris, M. 1999a, ApJ 514, 202 Google Scholar
Figer, D.F., Morris, M., Kim, S.S., Serabyn, E. 1999b, in: Falcke, H., Cotera, A., Duschl, W., Melia, F., Rieke, M. (eds.), The Central Parsecs of the Galaxy, ASP-CS in press Google Scholar
Figer, D.F. et al. 1999c, in preparation Google Scholar
Genzel, R., Thatte, N., Krabbe, A., Kroker, H., Tacconi-Garman, 1996, ApJ 472, 153 Google Scholar
Kim, S.S., et al. 1999, in preparation Google Scholar
MacKenty, J.W., et al. 1997, NICMOS Instrument Handbook, V2.0 (Baltimore: STScI)Google Scholar
Meynet, G. 1995, A&A 298, 767 Google Scholar
Meynet, G., Maeder, A., Schaller, G., Schaerer, D., Charbonnel, C. 1994, A&AS 103, 97 Google Scholar
Mezger, P.G., Duschl, W.J., Zylka, R. 1996, The A&A Rev. 7, 289 Google Scholar
Morris, M. 1993, ApJ, 408, 496 Google Scholar
Nagata, T., Woodward, C.E., Shure, M., Kobayashi, N. 1995, AJ 109, 1676 Google Scholar
Serabyn, E., Shupe, D., Figer, D.F. 1998, Nature 394, 448 Google Scholar
Serabyn, E., Shupe, D., Figer, D.F. 1999, in: Falcke, H., Cotera, A., Duschl, W., Melia, F., Rieke, M. (eds.), The Central Parsecs of the Galaxy, ASP-CS in press Google Scholar
Stetson, P. 1987, PASP 99, 191 Google Scholar