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An intermediate-mass black hole in the centre of the globular cluster 47 Tucanae

A Corrigendum to this article was published on 03 May 2017

Abstract

Intermediate-mass black holes should help us to understand the evolutionary connection between stellar-mass and super-massive black holes1. However, the existence of intermediate-mass black holes is still uncertain, and their formation process is therefore unknown2. It has long been suspected that black holes with masses 100 to 10,000 times that of the Sun should form and reside in dense stellar systems3,4,5,6. Therefore, dedicated observational campaigns have targeted globular clusters for many decades, searching for signatures of these elusive objects. All candidate signatures appear radio-dim and do not have the X-ray to radio flux ratios required for accreting black holes7. Based on the lack of an electromagnetic counterpart, upper limits of 2,060 and 470 solar masses have been placed on the mass of a putative black hole in 47 Tucanae (NGC 104) from radio and X-ray observations, respectively8,9. Here we show there is evidence for a central black hole in 47 Tucanae with a mass of solar masses when the dynamical state of the globular cluster is probed with pulsars. The existence of an intermediate-mass black hole in the centre of one of the densest clusters with no detectable electromagnetic counterpart suggests that the black hole is not accreting at a sufficient rate to make it electromagnetically bright and therefore, contrary to expectations, is gas-starved. This intermediate-mass black hole might be a member of an electromagnetically invisible population of black holes that grow into supermassive black holes in galaxies.

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Figure 1: Projected distribution of neutron stars in 47 Tuc.
Figure 2: Kinematic data for 47 Tuc compared with theoretical models.
Figure 3: Comparison of N-body model likelihoods of 47 Tuc.
Figure 4: Inferred masses of the black hole and the globular cluster.

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References

  1. Volonteri, M. The formation and evolution of massive black holes. Science 337, 544–547 (2012)

    Article  CAS  PubMed  ADS  Google Scholar 

  2. Baumgardt, H., Makino, J. & Hut, P. Which globular clusters contain intermediate-mass black holes? Astrophys. J. 620, 238–243 (2005)

    Article  CAS  ADS  Google Scholar 

  3. Sigurdsson, S. & Hernquist, L. Primordial black holes in globular clusters. Nature 364, 423–425 (1993)

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  5. Miller, M. C. & Hamilton, D. P. Production of intermediate-mass black holes in globular clusters. Mon. Not. R. Astron. Soc. 330, 232–240 (2002)

    Article  CAS  ADS  Google Scholar 

  6. Maccarone, T. J., Kundu, A., Zepf, S. E. & Rhode, K. L. A black hole in a globular cluster. Nature 445, 183–185 (2007)

    Article  CAS  PubMed  ADS  Google Scholar 

  7. Strader, J. et al. No evidence for intermediate-mass black holes in globular clusters: strong constraints from the JVLA. Astrophys. J. 750, L27 (2012)

    Article  ADS  Google Scholar 

  8. De Rijcke, S., Buyle, P. & Dejonghe, H. Upper limits on the central black hole masses of 47Tuc and NGC 6397 from radio continuum emission. Mon. Not. R. Astron. Soc. 368, L43–L46 (2006)

    Article  ADS  Google Scholar 

  9. Grindlay, J. E., Heinke, C., Edmonds, P. D. & Murray, S. S. High-resolution X-ray imaging of a globular cluster core: compact binaries in 47Tuc. Science 292, 2290–2295 (2001)

    Article  CAS  PubMed  ADS  Google Scholar 

  10. Freire, P. C. et al. Further results from the timing of the millisecond pulsars in 47 Tucanae. Mon. Not. R. Astron. Soc. 340, 1359–1374 (2003)

    Article  ADS  Google Scholar 

  11. Ridolfi, A. et al. Long-term observations of the pulsars in 47 Tucanae — I. A study of four elusive binary systems. Mon. Not. R. Astron. Soc. 462, 2918–2933 (2016)

    Article  CAS  ADS  Google Scholar 

  12. Pan, Z. et al. Discovery of two new pulsars in 47 Tucanae (NGC 104). Mon. Not. R. Astron. Soc. 459, L26–L30 (2016)

    Article  ADS  Google Scholar 

  13. Phinney, E. S. Pulsars as probes of Newtonian dynamical systems. Phil. Trans. R. Soc. Lond. A 341, 39–75 (1992)

    Article  ADS  Google Scholar 

  14. Baumgardt, H. N-body modeling of globular clusters: masses, mass-to-light ratios and intermediate-mass black holes. Mon. Not. R. Astron. Soc. 464, 2174–2202 (2017)

    Article  CAS  ADS  Google Scholar 

  15. McLaughlin, D. E. et al. Hubble Space Telescope proper motions and stellar dynamics in the core of the globular cluster 47 Tucanae. Astrophys. J. Suppl. Ser. 166, 249–297 (2006)

    Article  CAS  ADS  Google Scholar 

  16. Watkins, L. L., van der Marel, R. P., Bellini, A. & Anderson, J. Hubble Space Telescope Proper Motion (HSTPROMO) catalogs of galactic globular clusters. II. Kinematic profiles and maps. Astrophys. J. 803, 29 (2015)

    Article  ADS  Google Scholar 

  17. Pfahl, E., Rappaport, S. & Podsiadlowski, P. A comprehensive study of neutron star retention in globular clusters. Astrophys. J. 573, 283–305 (2002)

    Article  ADS  Google Scholar 

  18. Ivanova, N., Heinke, C. O., Rasio, F. A., Belczynski, K. & Fregeau, J. M. Formation and evolution of compact binaries in globular clusters — II. Binaries with neutron stars. Mon. Not. R. Astron. Soc. 386, 553–576 (2008)

    Article  CAS  ADS  Google Scholar 

  19. Bahcall, J. N. & Wolf, R. A. Star distribution around a massive black hole in a globular cluster. Astrophys. J. 209, 214–232 (1976)

    Article  ADS  Google Scholar 

  20. Smith, G. H. Globular cluster winds driven by main-sequence stars. Publ. Astron. Soc. Pacif. 111, 980–985 (1999)

    Article  ADS  Google Scholar 

  21. Scott, E. H. & Durisen, R. H. Nova-driven winds in globular clusters. Astrophys. J. 222, 612–620 (1978)

    Article  ADS  Google Scholar 

  22. Coleman, G. D. & Worden, S. P. Large-scale winds driven by flare-star mass loss. Astrophys. J. 218, 792–800 (1977)

    Article  ADS  Google Scholar 

  23. Spergel, D. N. Evacuation of gas from globular clusters by winds from millisecond pulsars. Nature 352, 221–222 (1991)

    Article  ADS  Google Scholar 

  24. Freire, P. C. et al. Detection of ionized gas in the globular cluster 47 Tucanae. Astrophys. J. 557, L105–L108 (2001)

    Article  ADS  Google Scholar 

  25. Giersz, M., Leigh, N., Hypki, A., Lützgendorf, N. & Askar, A. MOCCA code for star cluster simulations — IV. A new scenario for intermediate mass black hole formation in globular clusters. Mon. Not. R. Astron. Soc. 454, 3150–3165 (2015)

    Article  ADS  Google Scholar 

  26. Soria, R. et al. Super-Eddington mechanical power of an accreting black hole in M83. Science 343, 1330–1333 (2014)

    Article  CAS  PubMed  ADS  Google Scholar 

  27. Portegies Zwart, S. F., Baumgardt, H., Hut, P., Makino, J. & McMillan, S. L. W. Formation of massive black holes through runaway collisions in dense young star clusters. Nature 428, 724–726 (2004)

    Article  ADS  CAS  Google Scholar 

  28. Morscher, M., Pattabiraman, B., Rodriguez, C., Rasio, F. A. & Umbreit, S. The dynamical evolution of stellar black holes in globular clusters. Astrophys. J. 800, 9 (2015)

    Article  ADS  Google Scholar 

  29. Alexander, T. & Natarajan, P. Rapid growth of seed black holes in the early universe by supra-exponential accretion. Science 345, 1330–1333 (2014)

    Article  CAS  PubMed  ADS  Google Scholar 

  30. Richstone, D. et al. Supermassive black holes and the evolution of galaxies. Nature 395, A14–A19 (1998)

    CAS  Google Scholar 

  31. Camilo, F., Lorimer, D. R., Freire, P., Lyne, A. G. & Manchester, R. N. Observations of 20 millisecond pulsars in 47 Tucanae at 20 centimeters. Astrophys. J. 535, 975–990 (2000)

    Article  ADS  Google Scholar 

  32. Freire, P. C. et al. Timing the millisecond pulsars in 47 Tucanae. Mon. Not. R. Astron. Soc. 326, 901–915 (2001)

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  34. Nitadori, K. & Aarseth, S. J. Accelerating NBODY6 with graphics processing units. Mon. Not. R. Astron. Soc. 424, 545–552 (2012)

    Article  ADS  Google Scholar 

  35. VandenBerg, D. A., Brogaard, K., Leaman, R. & Casagrande, L. The ages of 55 globular clusters as determined using an improved method along with color-magnitude diagram constraints, and their implications for broader issues. Astrophys. J. 775, 134 (2013)

    Article  ADS  CAS  Google Scholar 

  36. Baumgardt, H., Makino, J., Hut, P., McMillan, S. & Portegies Zwart, S. A dynamical model for the globular cluster G1. Astrophys. J. 589, L25–L28 (2003)

    Article  ADS  Google Scholar 

  37. McNamara, B. J., Harrison, T. E., Baumgardt, H. & Khalaj, P. A search for an intermediate-mass black hole in the core of the globular cluster NGC 6266. Astrophys. J. 745, 175 (2012)

    Article  ADS  Google Scholar 

  38. Jalali, B. et al. A dynamical N-body model for the central region of ω Centauri. Astron. Astrophys. 538, A19 (2012)

    Article  Google Scholar 

  39. Harris, W. E. A catalog of parameters for globular clusters in the Milky Way. Astron. J. 112, 1487 (1996)

    Article  ADS  Google Scholar 

  40. Harris, W. E. A new catalog of globular clusters in the Milky Way. Preprint at https://arxiv.org/abs/1012.3224 (2010)

  41. Baumgardt, H., Makino, J. & Ebisuzaki, T. Massive black holes in star clusters. II. Realistic cluster models. Astrophys. J. 613, 1143–1156 (2004)

    Article  CAS  ADS  Google Scholar 

  42. Goodman, J. & Hut, P. Primordial binaries and globular cluster evolution. Nature 339, 40–42 (1989)

    Article  ADS  Google Scholar 

  43. Giersz, M. & Heggie, D. C. Monte Carlo simulations of star clusters — VII. The globular cluster 47 Tuc. Mon. Not. R. Astron. Soc. 410, 2698–2713 (2011)

    Article  ADS  Google Scholar 

  44. Lützgendorf, N., Baumgardt, H. & Kruijssen, J. M. D. N-body simulations of globular clusters in tidal fields: effects of intermediate-mass black holes. Astron. Astrophys. 558, A117 (2013)

    Article  ADS  Google Scholar 

  45. Hurley, J. R., Pols, O. R. & Tout, C. A. Comprehensive analytic formulae for stellar evolution as a function of mass and metallicity. Mon. Not. R. Astron. Soc. 315, 543–569 (2000)

    Article  CAS  ADS  Google Scholar 

  46. Albrow, M. D. et al. The frequency of binary stars in the core of 47 Tucanae. Astrophys. J. 559, 1060–1081 (2001)

    Article  ADS  Google Scholar 

  47. Kullback, S. & Leibler, R. A. On information and sufficiency. Ann. Math. Stat. 22, 79–86 (1951)

    Article  MathSciNet  MATH  Google Scholar 

  48. Kiziltan, B. & Thorsett, S. E. Constraints on pulsar evolution: the joint period-spin-down distribution of millisecond pulsars. Astrophys. J. 693, L109–L112 (2009)

    Article  CAS  ADS  Google Scholar 

  49. Guhathakurta, P., Yanny, B., Schneider, D. P. & Bahcall, J. N. Globular cluster photometry with the Hubble Space Telescope. I — Description of the method and analysis of the core of 47 Tuc. Astron. J. 104, 1790–1817 (1992)

    Article  ADS  Google Scholar 

  50. Calzetti, D., de Marchi, G., Paresce, F. & Shara, M. The center of gravity and density profile of 47 Tucanae. Astrophys. J. 402, L1–L4 (1993)

    Article  ADS  Google Scholar 

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Acknowledgements

This work was supported in part by the Black Hole Initiative at Harvard University, through the grant from the John Templeton Foundation.

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Authors and Affiliations

Authors

Contributions

B.K. initiated the project, led the collaboration, and wrote the manuscript. H.B. calculated the N-body models. A.L. made contributions to the conceptual definition of the project. All authors contributed to the analysis.

Corresponding author

Correspondence to Bülent Kızıltan.

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The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Cluster surface brightnesses and corresponding neutron star spatial distributions in N-body models for projected half-light radii.

The solid, dashed and dotted lines represent N-body models with an IMBH, with and without primordial binaries, respectively. a, All models have roughly comparable surface brightnesses; in contrast, b, the distribution of neutron stars is notably different for the IMBH model. The neutron star spatial distributions for N-body simulations with and without primordial binaries are similar. Therefore, it is unlikely that primordial binaries play a considerable role in shaping the final segregation profile of clusters with an IMBH.

Extended Data Figure 2 Comparison of the observed and predicted pulsar accelerations.

The observed acceleration (shaded areas) for each pulsar (named at the top of each panel) in 47 Tuc is compared with the integrated acceleration distributions for pulsars with the same line-of-sight distance predicted from N-body simulations (solid line, models with IMBH; dashed line, model without IMBH). The KL divergence method is used to calculate the integrated information entropy between distributions (equation (1)). The shaded areas show the 68%, 95% and 99% range of possible accelerations experienced owing to the gravitational potential of the cluster. Darker shades represent higher probability. The ambiguity is largely due to the unknown intrinsic spin-down of individual pulsars.

Extended Data Figure 3 Predictive power correlates with number of observed pulsars.

Shown are the normalized probabilities of N-body models with different black hole masses, as in Fig. 4a, for different numbers of randomly selected pulsars. The converging inference with increasing number of pulsars is indicative of statistical learning and demonstrates that the information comes from observations. The line thickness scales with the level of ambiguity for each inference.

Extended Data Table 1 Pulsars with timing solutions in 47 Tuc (NGC 104)

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Kızıltan, B., Baumgardt, H. & Loeb, A. An intermediate-mass black hole in the centre of the globular cluster 47 Tucanae. Nature 542, 203–205 (2017). https://doi.org/10.1038/nature21361

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