Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Formation of massive black holes through runaway collisions in dense young star clusters

Abstract

A luminous X-ray source is associated with MGG 11—a cluster of young stars 200 pc from the centre of the starburst galaxy M 82 (refs 1, 2). The properties of this source are best explained3,4 by invoking a black hole with a mass of at least 350 solar masses (350 M), which is intermediate between stellar-mass and supermassive black holes. A nearby but somewhat more massive cluster (MGG 9) shows no evidence of such an intermediate-mass black hole1,3, raising the issue of just what physical characteristics of the clusters can account for this difference. Here we report numerical simulations of the evolution and motion of stars within the clusters, where stars are allowed to merge with each other. We find that for MGG 11 dynamical friction leads to the massive stars sinking rapidly to the centre of the cluster, where they participate in a runaway collision. This produces a star of 800–3,000 M, which ultimately collapses to a black hole of intermediate mass. No such runaway occurs in the cluster MGG 9, because the larger cluster radius leads to a mass segregation timescale a factor of five longer than for MGG 11.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

  • Nuclear star clusters

    The Astronomy and Astrophysics Review Open Access 06 July 2020

  • A MODEST review

    Computational Astrophysics and Cosmology Open Access 06 November 2018

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Chandra X-ray image of the relevant part of the starburst galaxy M 82 with the observed star clusters indicated.
Figure 2: The growth in mass of the collision runaway star with time.
Figure 3: The area of parameter space for which runaway collision can occur, and where the process is prevented.

References

  1. Matsumoto, H. & Tsuru, T. G. X-ray evidence of an AGN in M82. Publ. Astron. Soc. Jpn 51, 321–331 (1999); Erratum. Publ. Astron. Soc. Jpn. 51, 567 (1999)

    ADS  CAS  Article  Google Scholar 

  2. Kaaret, P. et al. Chandra high-resolution camera observations of the luminous X-ray source in the starburst galaxy M82. Mon. Not. R. Astron. Soc. 321, L29–L32 (2001)

    ADS  CAS  Article  Google Scholar 

  3. Matsumoto, H. et al. Discovery of a luminous, variable, off-center source in the nucleus of M82 with the Chandra high-resolution camera. Astrophys. J. 547, L25–L28 (2001)

    ADS  CAS  Article  Google Scholar 

  4. Strohmayer, T. E. & Mushotsky, R. F. Discovery of X-ray quasi-periodic oscillations from an ultraluminous X-ray source in M82: Evidence against beaming. Astrophys. J. 586, L61–L64 (2003)

    ADS  Article  Google Scholar 

  5. McCrady, N., Gilbert, A. M. & Graham, J. R. Kinematic masses of super star clusters in M82 from high-resolution near-infrared spectroscopy. Astrophys. J. 596, 240–252 (2003)

    ADS  Article  Google Scholar 

  6. Portegies Zwart, S. F., Makino, J., McMillan, S. L. W. & Hut, P. Star cluster ecology. III. Runaway collisions in young compact star clusters. Astron. Astrophys. 348, 117–126 (1999)

    ADS  Google Scholar 

  7. Portegies Zwart, S. F. & McMillan, S. L. W. The runaway growth of intermediate-mass black holes in dense star clusters. Astrophys. J. 576, 899–907 (2002)

    ADS  CAS  Article  Google Scholar 

  8. Gürkan, M. A., Freitag, M. & Rasio, F. A. Formation of massive black holes in dense star clusters. I. Mass segregation and core collapse. Astrophys. J. (in the press); preprint at 〈http://arxiv.org/abs/astro-ph/0308449〉 (2003)

  9. Ebisuzaki, T. et al. Missing link found? The “runaway” path to supermassive black holes. Astrophys. J. 562, L19–L22 (2001)

    ADS  Article  Google Scholar 

  10. Spitzer, L. Jr & Hart, M. H. Random gravitational encounters and the evolution of spherical systems. I. Method. Astrophys. J. 164, 399–409 (1971)

    ADS  Article  Google Scholar 

  11. Portegies Zwart, S. F., McMillan, S. L. W., Hut, P. & Makino, J. Star cluster ecology-IV. Dissection of an open star cluster: photometry. Mon. Not. R. Astron. Soc. 321, 199–226 (2001)

    ADS  Article  Google Scholar 

  12. Hut, P., Makino, J., McMillan, S. L. W. & Portegies Zwart, S. Starlabhttp://manybody.org/manybody/starlab.html〉 (1995).

  13. Aarseth, S. J. From NBODY1 to NBODY6: The growth of an industry. Publ. Astron. Soc. Pacif. 111, 1333–1346 (1999)

    ADS  Article  Google Scholar 

  14. Baumgardt, H. & Makino, J. Dynamical evolution of star clusters in tidal fields. Mon. Not. R. Astron. Soc. 340, 227–246 (2003)

    ADS  Article  Google Scholar 

  15. King, I. R. The structure of star clusters. III. Some simple dynamical models. Astron. J. 71, 64–75 (1966)

    ADS  Article  Google Scholar 

  16. Heger, A., Fryer, C. L., Woosley, S. E., Langer, N. & Hartmann, D. H. How massive single stars end their life. Astrophys. J. 591, 288–300 (2003)

    ADS  Article  Google Scholar 

  17. Stothers, B. & Chin, C.-W. On two theories of the cyclical outbursts of eta Carinae. Astrophys. J 489, 319–330 (1997)

    ADS  Article  Google Scholar 

  18. Ishii, M., Munetaka, U. & Kato, M. Core-halo structure of a chemically homogeneous massive star and bending of the zero-age main sequence. Publ. Astron. Soc. Jpn 51, 417–424 (1999)

    ADS  CAS  Article  Google Scholar 

  19. Hopman, C., Portegies Zwart, S. F. & Alexander, T. Ultraluminous X-ray sources as intermediate mass black holes fed by tidally captured stars. Astrophys. J. Lett. (submitted); preprint at 〈http://arxiv.org/abs/astro-ph/0312597〉 (2003)

  20. Heggie, D. C. & Hut, P. The Gravitational Million-Body Problem (Cambridge Univ. Press, Cambridge, 2003)

    Book  Google Scholar 

  21. Whitmore, B. C. et al. The luminosity function of young star clusters in “The Antennae” galaxies. Astrophys. J. 118, 1551–1576 (1999)

    Google Scholar 

  22. Mengel, S., Lehnert, M. D., Thatte, N. & Genzel, R. Dynamical masses of young star clusters in NGC 4038/4039. Astron. Astrophys. 383, 137–152 (2002)

    ADS  CAS  Article  Google Scholar 

  23. Zezas, A., Fabbiano, G., Rots, A. H. & Murray, S. S. Chandra observations of “The Antennae” galaxies (NGC 4038/4039). III. X-ray properties and multiwavelength associations of the X-ray source population. Astrophys. J. 577, 710–725 (2002)

    ADS  Article  Google Scholar 

  24. Piatti, A. E., Bica, E. & Clariá, J. J. Fundamental parameters for the highly reddened young open clusters Westerlund 1 and 2. Astron. Astrophys. Suppl. 127, 423–432 (1998)

    ADS  Article  Google Scholar 

  25. Moffat, A. F. J., Drissen, L. & Shara, M. M. NGC 3603 and its Wolf-Rayet stars: Galactic clone of R136 at the core of 30 Doradus, but without the massive surrounding cluster halo. Astrophys. J. 436, 183–193 (1994)

    ADS  Article  Google Scholar 

  26. Campbell, B. et al. Hubble Space Telescope planetary camera images of R136. Astron. J. 104, 1721–1742 (1992)

    ADS  Article  Google Scholar 

  27. Singer, D., Pugh, H. & Li, W. Supernovae 2004ak, 2004al, and 2004am. IAU Circ. No. 8297 (2004)

  28. Matsushita, M. S. et al. Formation of a massive black hole at the center of the superbubble in M82. Astrophys. J. 545, L107–L111 (2000)

    ADS  CAS  Article  Google Scholar 

  29. Salpeter, E. E. The luminosity function and stellar evolution. Astrophys. J. 121, 161–167 (1955)

    ADS  Article  Google Scholar 

  30. Kroupa, P. On the variation of the initial mass function. Mon. Not. R. Astron. Soc. 322, 231–246 (2001)

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We thank N. McCrady and D. Pooley for discussions on MGG 11, T. G. Tsuru for an accurate position of M82 X-1, and E. van den Heuvel for critically reading the manuscript. This work was supported by NASA ATP, the Royal Netherlands Academy of Sciences (KNAW), the Dutch Organization of Science (NWO), and the Netherlands Research School for Astronomy (NOVA).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Simon F. Portegies Zwart.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Information

Includes discussion of the selection of initial conditions, numerical methods, and the results of simulations of the star clusters MGG-9 and MGG-11; Supplementary Figure 1: Evolution of the core radius for four simulations of the star cluster MGG-11; Supplementary Figure 2: Stellar radius as a function of zero-age mass for various models of high-mass stars. (PDF 196 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Portegies Zwart, S., Baumgardt, H., Hut, P. et al. Formation of massive black holes through runaway collisions in dense young star clusters. Nature 428, 724–726 (2004). https://doi.org/10.1038/nature02448

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature02448

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing