Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-26T02:52:22.944Z Has data issue: false hasContentIssue false
  • English
  • Français

Is There a Compact Central Mass Concentration in Our Galaxy?

Published online by Cambridge University Press:  25 May 2016

Charles H. Townes
Charles H. Townes*
Affiliation:
University of California at Berkeley Berkeley, CA 94720

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Since the center of our own galaxy is the closest region of this type, it should provide a proving ground for our understanding of such regions. And fortunately, recent developments in radio, infrared, and x-ray astronomy allow us to look at the center of our galaxy in considerable detail – a privilege not possible in the visible region because of the rather dense dust clouds surrounding it. We find there many complex and interesting phenomena, including evidence for a compact central mass of a few million solar masses from the dynamics of stars and gases. However, its existence has been doubted because the radiant energy coming from the very center is much less than normal theoretical expectations for a black hole of such a mass. This discrepancy has led to speculation whether the velocity measurements could be misleading, whether the concentrated mass is in some form other than the expected black hole, whether the radiation might be taking place in an exotic form, being directed away from us or happening to be low at the moment, or whether our theories of such radiation are as yet incomplete. The general characteristics of the very central region of our galaxy will be reviewed along with the dynamic evidence for a large concentrated mass and comparison of the radiation it emits with that of various theoretical models.

Type
Chapter 3: What is the Nature of the Center of the Galaxy?
Information
Symposium - International Astronomical Union , Volume 169: Unsolved Problems of the Milky Way , 1996 , pp. 149 - 168
Copyright
Copyright © Kluwer 1996 

References

Aitken, D.K., Gezari, S., Smith, C.H., McCaughrean, M., and Roche, P.F. (1991) Ap.J., Vol. 380, pp. 419 CrossRefGoogle Scholar
Backer, D.H. private communication Google Scholar
Brown, G.E. and Bethe, H.A. 1994, to be published Google Scholar
Eckart, A., Genzel, R., Hofmann, R., Sams, B.J. and Tacconi-Garman, L.E. 1993, Ap.J., 407, L77.CrossRefGoogle Scholar
Eckart, A., Genzel, R., and Tacconi-Garman, L.E. 1994, private communication Google Scholar
Falcke, H., Biermann, P.L., Duschl, W.J., and Mezger, P.G. 1993, Astr. Ap., 270, 102 Google Scholar
Ford, H., Harms, R., Tsvetanov, Z., Davidson, A., Kriss, G., Bohlin, R., Hartig, G., Dressel, L., Kochbar, A.K., and Morgan, B. 1994, to be published Google Scholar
Genzel, R. Hollenbach, D., and Townes, C.H. 1994, Reports of Progress in Physics Google Scholar
Goodman, J. and Lee, H.M. 1989, Ap.J. 337, 84 CrossRefGoogle Scholar
Güsten, R., Genzel, R., Wright, M.C.H., Jaffe, D.T., Stutski, J., and Harris, A.I. 1987, Ap.J., 318, 124 CrossRefGoogle Scholar
Haller, J.W. 1992, Ph.D. Thesis, Univ. of Arizona Google Scholar
Haller, J.W., Rieke, M.J., and Rieke, G.H. 1992, BAAS, 24, 1178 Herbst, T.M., Beckwith, S.V.W., Forrest, W.J., and Pipher, J.L. 1993, A.J. 105, 956 Google Scholar
Jackson, J.M., Geis, N., Genzel, R., Harris, A.I., Madden, S., Poglitsch, A., Stacey, G.J., and Townes, C.H. 1993, Ap.J. 402, 173 CrossRefGoogle Scholar
Jansky, K.G. 1932, Proc. I.R.E. 20, 1920 CrossRefGoogle Scholar
Kormendy, J. 1993, Ann. Rev. Astr. Ap. Google Scholar
Kormendy, J., and Richstone, D. 1992, Ap.J. 393, 559 CrossRefGoogle Scholar
Lacy, J.H., Townes, C.H., and Hollenbach, D.J. 1982, Ap.J. 262, 120 CrossRefGoogle Scholar
Lauer, T.R. 1994, to be published Google Scholar
Lee, H.M. 1994, MNRAS, to be published Google Scholar
Melia, F. 1992, Ap.J., 387, L25 CrossRefGoogle Scholar
Morris, M. 1993, Ap.J., 408,496 CrossRefGoogle Scholar
Morris, M. and Yusef-Zadeh, F. 1987, AIP Conference Proceedings 155, ed. Backer, D.C. 127 Google Scholar
Ozernoy, L.M. 1989, The Galactic Center, ed. Morris, M., Kluwer (Dordrecht), 555 CrossRefGoogle Scholar
Rees, M.J. 1988, Nature 333, 523 CrossRefGoogle Scholar
Rieke, G.H. and Rieke, M.J. 1988, Ap.J. 330, L33 CrossRefGoogle Scholar
Roberts, D.A. and Goss, W.M. 1993, Ap.J. (Suppl.), 86, 133 CrossRefGoogle Scholar
Rogers, A.E.E., Doeleman, S., Wright, M.C.H., Bower, G.C., Backer, D.C., Padin, S., Phillips, J.A., Emerson, D.T., Greenhill, L., Moran, J.M., and Kellermann, K.I. 1994, Ap.J., to be published Google Scholar
Ruffert, M., and Melia, F. 1994, private communication Google Scholar
Sellgren, K., McGinn, M.T., Becklin, E.E., and Hall, D.N.B 1990, Ap.J. 359, 112 CrossRefGoogle Scholar
Serabyn, E. and Lacy, J.H. 1985, Ap.J. 293, 445 CrossRefGoogle Scholar
Serabyn, E., Lacy, J.H., Townes, C.H., and Bharat, R. 1988, Ap.J. 326, 171 CrossRefGoogle Scholar
Sunyaev, R.A., Markevitch, M., and Pavlinsky, J. 1993, Ap.J., 407, 606 CrossRefGoogle Scholar