Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-26T04:44:56.407Z Has data issue: false hasContentIssue false

Diameter and Proper Motion of Sgr A

Published online by Cambridge University Press:  25 May 2016

D. C. Backer*
Affiliation:
Astronomy Department & Radio Astronomy Laboratory University of California Berkeley, CA 94720 USA

Abstract

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.

The best hypothesis for the energy source of the compact, nonthermal radio source in the center of our galaxy, Sagittarius A (Sgr A), is accretion onto a massive black hole from winds emanating from nearby luminous stars. The hole mass, accretion rate, and ultimate fate of accreted matter are uncertain. In this report I give a summary of recent critical observations. The interpretation of these results supports this general hypothesis, and begins to place constraints on model parameters. If so, then Sgr A is a miniature version of extragalactic AGNs in a quiescent state.

Type
Chapter 3: What is the Nature of the Center of the Galaxy?
Copyright
Copyright © Kluwer 1996 

References

Alberdi, A., Lara, L., Marcaide, J.M., Elosegui, P., et al. (1993) Astron. Astrophys. , 277, pp. L1–4.Google Scholar
Backer, D. C., & Sramek, R. A. (1987) AIP Conf. Proc. , 155, pp. 163–5.Google Scholar
Backer, D. C. (1988) AIP Conf. Proc. , 174, pp. 111–6.Google Scholar
Backer, D.C., Zensus, J.A., Kellermann, K.I., Reid, M., et al. (1993) Science , 262, pp. 1414–16.CrossRefGoogle Scholar
Backer, D. C. (1994) in Nuclei of Normal Galaxies : Lessons from the Galactic Center , ed. Harris, A. & Genzel, R., [Kluwer: Dordrecht], in press.Google Scholar
Carlstrom, J.E., Lay, O.P., & Hills, R.E. (1993), BAAS , 25, pp. 859.Google Scholar
Eckart, A., Genzel, R., Hofmann, R., Sams, B.J., et al. (1993) Astrophys. J. , 407, pp. L77–80.Google Scholar
Falcke, H., Biermann, P.L., Duschl, W.J., & Mezger, P.G. (1993) Astron. Astrophys. , 270, pp. 102–6.Google Scholar
Frail, D.A., Diamond, P.J., Cordes, J.M., & van Langevelde, H.J. (1994) Astrophys. J. , 427, pp. L43–6.Google Scholar
Genzel, R., Hollenbach, D., & Townes, C.H. (1994) Rep. on Progr. in Physics , 57, pp. 417–79.Google Scholar
Goldreich, P., & Sridhar, S. (1994) Astrophys. J. , in press.Google Scholar
Goldwurm, A., Cordler, B., Paul, J., Ballet, J., et al. (1994) Nature , 371, pp. 589–91.Google Scholar
Higdon, J.C. (1984) Astrophys. J. , 285, pp. 109–23.CrossRefGoogle Scholar
Higdon, J.C. (1986) Astrophys. J. , 309, pp. 342–61.Google Scholar
Jauncey, D.L., Tzioumis, A.K., Preston, R.A., Meier, D.L., et al. (1989) Astron. J. , 98, pp. 44–8.Google Scholar
Krichbaum, T.P., Witzel, A., Graham, D.A., Standke, K.J., et al. (1993) Astron. Astrophys. , 275, pp. 375–89.Google Scholar
Krichbaum, T. (1994) in Nuclei of Normal Galaxies: Lessons from the Galactic Center , ed. Harris, A. & Genzel, R., [Kluwer : Dordrecht], in press.Google Scholar
Lo, K.Y., Backer, D.C., Ekers, R.D., Kellermann, K.I., et al. (1985) Nature , 315, pp. 124–6.CrossRefGoogle Scholar
Lo, K.Y., Backer, D.C., Kellermann, K.I., Reid, M., et al. (1993) Nature , 362, pp. 38–40.CrossRefGoogle Scholar
Melia, F., Jokipii, J.R., Narayanan, A. (1992) Astrophys. J. , 395, pp. L87–90.Google Scholar
Melia, F. (1992) Astrophys. J. , 387, pp. L25–8.Google Scholar
Melia, F. (1994) Astrophys. J. , 426, pp. 577–85.Google Scholar
Ozernoi, L. (1989) in Proc of IAU Symp. No. 136 , ed. Morris, M., [Kluwer: Dordrecht], pp. 555–66.Google Scholar
Ozernoi, L. (1993) AIP Conf. Proc. , 278, 6972.Google Scholar
Ozernoi, L. 1994, in Nuclei of Normal Galaxies: Lessons from the Galactic Center , ed. Harris, A. & Genzel, R., [Kluwer: Dordrecht], in press.Google Scholar
Rees, M. (1987) AIP Conf. Proc. , 83, pp. 166–76.Google Scholar
Reynolds, S.P., & McKee, C.F. (1980) Astrophys. J. , 239, pp. 893–7.Google Scholar
Rogers, A.E.E., Doeleman, S., Wright, M.C.H., Bower, G.C., Backer, D.C. et al. (1994) Astrophys. J. , 434, L59–62.Google Scholar
Ruffert, M., & Melia, F. (1994) Astron. Astrophys. , 288, pp. L29–32.Google Scholar
Sellgren, K., McGinn, M.T., Becklin, E.E., Hall, D.N.B. (1990) Astrophys. J. , 359, pp. 112–20.Google Scholar
Sunyaev, R., et al. (1991) Sov. Astr. Lett. , 17, 42–5.Google Scholar
van Langevelde, H.J., Frail, D.A., Cordes, J.M., & Diamond, P.J. (1992) Astrophys. J. , 396, pp. 686–95.Google Scholar
Wright, M.C.H., & Backer, D.C. (1993) Astrophys. J. , 417, pp. 560–4.Google Scholar
Yusef-Zadeh, F., Cotton, W., Wardle, M., Melia, F., & Roberts, D.A. (1994) Astrophys. J. , 434, L63–6.Google Scholar
Zylka, R., Mezger, P.G., & Lesch, H. (1992), Astron. Astrophys. , 261, pp. 119–29.Google Scholar