Skip to main content Accessibility help
×
Home
Hostname: page-component-559fc8cf4f-d5zgf Total loading time: 0.246 Render date: 2021-03-01T15:02:57.216Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": false, "newCiteModal": false, "newCitedByModal": true }

Hot stars in the Galactic Center

Published online by Cambridge University Press:  25 May 2016

Andreas Eckart
Affiliation:
Max Planck Institut für extraterrestrische Physik, D-85740, Garching, Germany
Thomas Ott
Affiliation:
Max Planck Institut für extraterrestrische Physik, D-85740, Garching, Germany
Reinhard Genzel
Affiliation:
Max Planck Institut für extraterrestrische Physik, D-85740, Garching, Germany
Dieter Lutz
Affiliation:
Max Planck Institut für extraterrestrische Physik, D-85740, Garching, Germany

Abstract

The central parsec of our Galaxy is powered by a cluster of young massive hot stars which formed a few million years ago. Within that cluster the seven most luminous (L >105.75 L) and moderately hot (T < 104.5 K) blue supergiants contribute half of the ionizing luminosity of that region. These stars probably formed when a dense cloud fell into the center < 107 years ago, was highly compressed there, and became gravitationally unstable. Over six years of high spatial resolution, near-infrared imaging and spectroscopy have made it possible to carry out a detailed investigation of the stars in the central cluster and its enclosed mass. As one result of a detailed variability study of the central cluster stars we found that the bright He I star IRS 16SW is a short-period variable with a period of ∼9.72 days. It is most likely an eclipsing binary with a lower mass limit of 100 solar masses. Line of sight velocities and proper motions have been measured for these hot stars (as well as ∼200 other stars) down to separations of less than five light days from the compact radio source Sgr A* at the dynamic center of the Milky Way. These confirmed measurements imply the presence of a central dark mass of 2.6 × 106 solar masses. The dark mass at the center of the Milky Way is currently the most compelling case for a massive black hole. Simple physical considerations show that this dark mass cannot consist of a stable cluster of stars, stellar remnants, substellar condensations or a degenerate gas of elementary particles but that at least 103 to 105 solar masses must be in the form of a massive black hole associated with Sgr A* itself.

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

Allen, D.A., Hyland, A.R., Hillier, D.J. 1990, MNRAS 244, 706 Google Scholar
Backer, D.C. 1996, in: Blitz, L. & Teuben, P. (eds.), Unsolved Problems of the Milky Way, Proc. IAU Symp. No. 169 (Kluwer: Dordrecht), p. 193 CrossRefGoogle Scholar
Balick, B., Brown, R.L. 1974, ApJ 194, 265 CrossRefGoogle Scholar
Blum, R.D., Sellgren, K., DePoy, D.L. 1995, ApJ 440, L17 CrossRefGoogle Scholar
Cotera, A.S., Erickson, E.F., Colgan, S.W.J., Simpson, J.P., Allen, D.A., Burton, M.G. 1996, ApJ 461, 750 CrossRefGoogle Scholar
Eckart, A., Genzel, R., Krabbe, A., Hofmann, R., van der Werf, P.P., Drapatz, S. 1992, Nature 335, 526 CrossRefGoogle Scholar
Eckart, A., Genzel, R., Hofmann, R., Sams, B., Tacconi-Garman, L.E. 1995, ApJ 445, L26 CrossRefGoogle Scholar
Eckart, A., Genzel, R. 1996, Nature 383, 415 CrossRefGoogle Scholar
Eckart, A., Genzel, R. 1997, MNRAS 284, 576 CrossRefGoogle Scholar
Figer, D.F., McLean, I.S., Morris, M. 1995, ApJ 447, L29 CrossRefGoogle Scholar
Figer, D.F., Najarro, F., Morris, M., McLean, I.S., Geballe, T.R., Ghez, A., Langer, N. 1998, ApJ 506, 384 CrossRefGoogle Scholar
Forrest, W.J., Shure, M.A., Pipher, J.L., Woodward, C.A. 1987, in: Backer, D. (ed.), The Galactic Center, AIP-CP 155, 153 Google Scholar
Genzel, R., Townes, C.H. 1987, ARAA 25, 377 CrossRefGoogle Scholar
Genzel, R., Thatte, N., Krabbe, A., Eckart, A., Kroker, H. Tacconi-Garman, L.E. 1996, ApJ 472, 153 CrossRefGoogle Scholar
Genzel, R., Eckart, A., Ott, T., Eisenhauer, F. 1997, MNRAS 291, 219 CrossRefGoogle Scholar
Ghez, A., Klein, B., Morris, M., Becklin, E. 1998, ApJ 509, 678 CrossRefGoogle Scholar
de Graauw, Th., Haser, L.N., Beintema, D.A., van der Hucht, K.A., et al. 1996, A&A 315, L49 Google Scholar
Greenhill, L.J., Jiang, D.R., Moran, J.M., Reid, M.J., Lo, K.Y., Claussen, M.J. 1995, ApJ 440, 619 CrossRefGoogle Scholar
Haller, J.W., Rieke, M.J., Rieke, G.H., Tamblyn, P., Close, L., Melia, F. 1996, ApJ 456, 194 CrossRefGoogle Scholar
Krabbe, A., Genzel, R., Drapatz, S., Rotaciuc, V. 1991, ApJ 382, L19 CrossRefGoogle Scholar
Krabbe, A., Genzel, R., Eckart, A., Najarro, F., Lutz, D., Cameron, M., Kroker, H., Tacconi-Garman, L.E., Thatte, N., Weitzel, L., Drapatz, S., Geballe, T., Sternberg, A., Kudritzki, R. 1995, ApJ 447, L95 CrossRefGoogle Scholar
Krichbaum, T.P., Graham, D.A., Witzel, A., Greve, A., Wink, J.E., Grewing, M., Colomer, F., de Vicente, P., Gómez-González, J., Baudry, A., Zensus, J.A. 1998, A&A 335, L106 Google Scholar
Lacy, J.H., Baas, F., Townes, C.H., Geballe, T.R. 1979, ApJ 227, L17 CrossRefGoogle Scholar
Lacy, J.H., Townes, C.H., Geballe, T.R., Hollenbach, D. 1980, ApJ 241,132 CrossRefGoogle Scholar
Lacy, J.H., Townes, C.H., Hollenbach, D.J. 1982, ApJ 262, 120 CrossRefGoogle Scholar
Lester, D.F., Dinerstein, H.L., Werner, M.W., Watson, D.M., Genzel, R., Storey, J.W.V. 1987, ApJ 320, 573 CrossRefGoogle Scholar
Lutz, D., Feuchtgruber, H., Genzel, R., et al. 1996, A&A 315, L269 Google Scholar
Lynden-Bell, D., Rees, M. 1971, MNRAS 152, 461 CrossRefGoogle Scholar
Maoz, E. 1995, ApJ 447, L91 CrossRefGoogle Scholar
Menten, K.M., Reid, M., Eckart, A., Genzel, R. 1997, ApJ 475, L111 CrossRefGoogle Scholar
Myoshi, M, Moran, J.M., Hernstein, J., Greenhill, L.J., Nakai, N., Diamond, P., Inoue, M. 1995, Nature 373, 127 CrossRefGoogle Scholar
Nagata, T., Woodward, C.E., Shure, M., Pipher, J.L., Okuda, H. 1990, ApJ 351, 83 CrossRefGoogle Scholar
Najarro, F., Hillier, D.J., Kudritzki, R.P., Krabbe, A., Genzel, R., Lutz, D., Drapatz, S., Geballe, T.R. 1994, A&A 285, 573 Google Scholar
Najarro, F., Krabbe, A., Genzel, R., Lutz, D., Kudritzki, R.P., Hillier, D.J. 1997, A&A 325, 700 Google Scholar
Okuda, H., Shibai, H., Nagakawa, T., Matsuhara, H., Kobayashi, Y., Kaifu, N., Nagata, T., Gatley, I., Geballe, T.R. 1990, ApJ 351, 89 CrossRefGoogle Scholar
Ott, T., Eckart, A., Genzel, R. 1999, ApJ submitted Google Scholar
Ramirez, S.V., Sellgren, K., Carr, J., Balachandran, S., Blum, R.D., Terndrup, D. 1997, BAAS 191, #107.05 Google Scholar
Rieke, G.H., Rieke, M.J. 1988, ApJ 330, L33 CrossRefGoogle Scholar
Rieke, M.J. 1996, ApJ 456, 206 Google Scholar
Schaerer, D., Meynet, G., Maeder, A., Schaller, G. 1993, A&AS 98, 523 Google Scholar
Schaller, G., Schaerer, D., Meynet, G., Maeder, A. 1992, A&AS 96, 269 Google Scholar
Sellgren, K., McGinn, M.T., Becklin, E., Hall, D.N.B. 1990, ApJ 359, 112 CrossRefGoogle Scholar
Sellgren, K., Carr, J.S., Balachandran, S.C. 1997, in: Sofue, Y. (ed.), The Central Regions of the Galaxy and Galaxies, Proc. IAU Symp. No. 184 (Dordrecht: Kluwer), p. 21.Google Scholar
Serabyn, E., Lacy, J. 1985, ApJ 293, 445 CrossRefGoogle Scholar
Serabyn, E., Shupe, D., Figer, D.F. 1998, Nature 394, 448 CrossRefGoogle Scholar
Shields, J.C., Ferland, G.J. 1994, ApJ 258, 134 Google Scholar
Tamblyn, P., Rieke, G.H., Hanson, M.M., Close, L.M., McCarthy, D.W., Rieke, M.J. 1996, ApJ 456, 206 CrossRefGoogle Scholar
Wollman, E.R., Geballe, T.R., Lacy, J.H., Townes, C.H., Rank, D.M. 1977, ApJ 218, L103 CrossRefGoogle Scholar
Yusef-Zadeh, F., Wardle, M., Cotton, W., Walker, C., Zhao, J.-H., Melia, F. 1993, ApJ 405, 584 CrossRefGoogle Scholar

Full text views

Full text views reflects PDF downloads, PDFs sent to Google Drive, Dropbox and Kindle and HTML full text views.

Total number of HTML views: 0
Total number of PDF views: 48 *
View data table for this chart

* Views captured on Cambridge Core between September 2016 - 1st March 2021. This data will be updated every 24 hours.

Access

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Hot stars in the Galactic Center
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

Hot stars in the Galactic Center
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

Hot stars in the Galactic Center
Available formats
×
×

Reply to: Submit a response


Your details


Conflicting interests

Do you have any conflicting interests? *