Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-23T11:20:26.566Z Has data issue: false hasContentIssue false

Nuclear Star Clusters

Published online by Cambridge University Press:  31 March 2017

Nadine Neumayer*
Affiliation:
Max-Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany email: [email protected]
Rights & Permissions [Opens in a new window]

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 centers of galaxies host two distinct, compact components: massive black holes and nuclear star clusters. Nuclear star clusters are the densest stellar systems in the universe, with masses of ~ 107M and sizes of ~ 5pc. They are almost ubiquitous at the centres of nearby galaxies with masses similar to, or lower than the Milky Way. Their occurrence both in spirals and dwarf elliptical galaxies appears to be a strong function of total galaxy light or mass. Nucleation fractions are up to 100% for total galaxy magnitudes of MB = −19mag or total galaxy luminosities of about LB = 1010L and falling nucleation fractions for both smaller and higher galaxy masses. Although nuclear star clusters are so common, their formation mechanisms are still under debate. The two main formation scenarios proposed are the infall and subsequent merging of star clusters and the in-situ formation of stars at the center of a galaxy. Here, I review the state-of-the-art of nuclear star cluster observations concerning their structure, stellar populations and kinematics. These observations are used to constrain the proposed formation scenarios for nuclear star clusters. Constraints from observations show, that likely both cluster infall and in-situ star formation are at work. The relative importance of these two mechanisms is still subject of investigation.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2017 

References

Agarwal, M. & Milosavljević, M. 2011, ApJ, 729, 35 Google Scholar
Antonini, F. 2013, ApJ, 763, 62 CrossRefGoogle Scholar
Antonini, F., Barausse, E., & Silk, J. 2015, ApJLetters, 806, L8 Google Scholar
Arca-Sedda, M. & Capuzzo-Dolcetta, R. 2014, MNRAS, 444, 3738 CrossRefGoogle Scholar
Bartko, H., Martins, F., Trippe, S., et al. 2010, ApJ, 708, 834 Google Scholar
Böker, T., Laine, S., van der Marel, R. P., et al. 2002, AJ, 123, 1389 Google Scholar
Böker, T., Sarzi, M., McLaughlin, D. E., et al. 2004, AJ, 127, 105 Google Scholar
Capuzzo-Dolcetta, R. 1993, ApJ, 415, 616 CrossRefGoogle Scholar
Carollo, C. M., Stiavelli, M., & Mack, J. 1998, AJ, 116, 68 CrossRefGoogle Scholar
Carson, D. J., Barth, A. J., Seth, A. C., et al. 2015, AJ, 149, 170 CrossRefGoogle Scholar
Côté, P., Piatek, S., Ferrarese, L., et al. 2006, ApJS, 165, 57 Google Scholar
De Lorenzi, F., Hartmann, M., Debattista, V., et al. 2013, MNRAS, 429, 2974 Google Scholar
Do, T., Lu, J. R., Ghez, A. M., et al. 2013, ApJ, 764, 154 CrossRefGoogle Scholar
den Brok, M., Peletier, R. F., Seth, A., et al. 2014, MNRAS, 445, 2385 Google Scholar
den Brok, M., Seth, A. C., Barth, A. J., et al. 2015, ApJ, 809, 101 CrossRefGoogle Scholar
Evstigneeva, E. A., Gregg, M. D., Drinkwater, M. J., & Hilker, M. 2007, AJ, 133, 1722 Google Scholar
Feldmeier, A., Neumayer, N., Seth, A., et al. 2014, A&A, 570, A2 Google Scholar
Feldmeier-Krause, A., Neumayer, N., Schödel, R., et al. 2015, A&A, 584, A2 Google Scholar
Georgiev, I. Y & Böker, T. 2014, MNRAS, 441, 3570 Google Scholar
Gnedin, O. Y., Ostriker, J. P., & Tremaine, S. 2014, ApJ, 785, 71 CrossRefGoogle Scholar
Hartmann, M., Debattista, V. P., Seth, A., et al. 2011, MNRAS, 418, 2697 Google Scholar
Koleva, M., Prugniel, P., de Rijcke, S., & Zeilinger, W. W. 2011, MNRAS, 417, 1643 Google Scholar
Lotz, J. M., Miller, B. W., & Ferguson, H. C. 2004, ApJ, 613, 262 CrossRefGoogle Scholar
Lyubenova, M., van den Bosch, R. C. E., Côté, P., et al. 2013, MNRAS, 431, 3364 CrossRefGoogle Scholar
Milosavljević, M. 2004, ApJL 605, L13 Google Scholar
Misgeld, I. & Hilker, M. 2011, MNRAS, 414, 3699 Google Scholar
Neumayer, N., Walcher, C. J., Andersen, D., et al. 2011, MNRAS, 413, 1875 Google Scholar
Neumayer, N. & Walcher, C. J. 2012, Advances in Astronomy, 2012Google Scholar
Norris, M. A., Kannappan, S. J., Forbes, D. A., et al. 2014, MNRAS, 443, 1151 Google Scholar
Perets, H. B. & Mastrobuono-Battisti, A. 2014, ApJL, 784, L44 Google Scholar
Pflamm-Altenburg, J. & Kroupa, P. 2009, MNRAS, 397, 488 CrossRefGoogle Scholar
Rossa, J., van der Marel, R. P., Böker, T., et al. 2006, AJ, 132, 1074 CrossRefGoogle Scholar
Schinnerer, E., Böker, T., Meier, D. S., & Calzetti, D. 2008, ApJL, 684, L21 Google Scholar
Schödel, R., Feldmeier, A., Kunneriath, D., et al. 2014, A&A, 566, A47 Google Scholar
Seth, A. C., Dalcanton, J. J., Hodge, P. W., & Debattista, V. P. 2006, AJ, 132, 2539 Google Scholar
Seth, A. C., Blum, R. D., Bastian, N., et al. 2008, ApJ, 687, 997 CrossRefGoogle Scholar
Seth, A. C., Cappellari, M., Neumayer, N., et al. 2010, ApJ, 714, 713 Google Scholar
Seth, A. C., van den Bosch, R., Mieske, S., et al. 2014, Nature, 513, 398 Google Scholar
Stolovy, S., Ramirez, S., Arendt, R. G., et al. 2006, Journal of Physics Conference Series, 54, 176 Google Scholar
Støstad, M., Do, T., Murray, N., et al. 2015, ApJ, 808, 106 CrossRefGoogle Scholar
Tremaine, S. D., Ostriker, J. P., & Spitzer, L. Jr. 1975, ApJ, 196, 407 CrossRefGoogle Scholar
Turner, M. L., Côté, P., Ferrarese, L., et al. 2012, ApJS, 203, 5 Google Scholar
Walcher, C. J., Böker, T., Charlot, S., et al. 2006, ApJ, 649, 692 Google Scholar
Walcher, C. J., van der Marel, R. P., McLaughlin, D., et al. 2005, ApJ, 618, 237 Google Scholar