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A runaway collision in a young star cluster as the origin of the brightest supernova


Supernova SN 2006gy in the galaxy NGC 1260 is the most luminous recorded1,2,3,4. Its progenitor might have been a very massive (>100, where is the mass of the Sun) star5, but that interpretation is incompatible with hydrogen in the spectrum of the supernova; stars >40 are believed to have shed their hydrogen envelopes several hundred thousand years before the explosion6. Alternatively, the progenitor might have arisen from the merger of two massive stars7. Here we show that the collision frequency of massive stars in a dense and young cluster (of the kind to be expected near the centre of a galaxy) is sufficient to provide a reasonable chance that SN 2006gy resulted from such a bombardment. If this is the correct explanation, then we predict that when the supernova fades (in a year or so) a dense cluster of massive stars will become visible at the site of the explosion.

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Figure 1: Mass of the collision runaway star as a function of cluster mass and its distance to the centre of NGC 1260.


  1. Quimby, R. Supernova 2006gy in NGC 1260. Central Bureau Electron. Teleg. 644, 1 (2006)

    ADS  Google Scholar 

  2. Harutyunyan, A. et al. Supernova 2006gy in NGC 1260. Central Bureau Electron. Teleg. 647, 1 (2006)

    ADS  Google Scholar 

  3. Prieto, J. L., Garnavich, P., Chronister, A. & Connick, P. 2006gy in NGC 1260. Central Bureau Electron. Teleg. 648, 1 (2006)

    ADS  Google Scholar 

  4. Foley, R. J. et al. Supernova 2006gy in NGC 1260. Central Bureau Electron. Teleg. 695, 1 (2006)

    ADS  Google Scholar 

  5. Smith, N. et al. SN 2006gy: discovery of the most luminous supernova ever recorded, powered by the death of an extremely massive star like Eta Carinae. Preprint at 〈〉 (2006)

  6. Meynet, G. & Maeder, A. Stellar evolution with rotation. XI. Wolf-Rayet star populations at different metallicities. Astron. Astrophys. 429, 581–598 (2005)

    Article  ADS  CAS  Google Scholar 

  7. Ofek, E. O. et al. SN 2006gy: An extremely luminous supernova in the galaxy NGC 1260. Astrophys. J. Lett. 659, L13–L16 (2007)

    Article  ADS  CAS  Google Scholar 

  8. 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 

  9. Suzuki, T. K. et al. Evolution of collisionally merged massive stars. Preprint at 〈〉 (2007)

  10. Fryer, C. L. & Kalogera, V. Theoretical black hole mass distributions. Astrophys. J. 554, 548–560 (2001)

    Article  ADS  Google Scholar 

  11. 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  Google Scholar 

  12. Cotera, A. S. et al. The discovery of hot stars near the galactic center thermal radio filaments. Astrophys. J. 461, 750–761 (1996)

    Article  ADS  CAS  Google Scholar 

  13. Cotera, A. S. et al. A new cluster of hot stars near the galactic center. Bull. Am. Astron. Soc. 1262–1263. (1992)

  14. Dutra, C. M. & Bica, E. New star clusters projected close to the galactic centre. Astron. Astrophys. 359, L9–L12 (2000)

    ADS  Google Scholar 

  15. Dutra, C. M. et al. NTT infrared imaging of star cluster candidates towards the central parts of the Galaxy. Astron. Astrophys. 408, 127–134 (2003)

    Article  ADS  Google Scholar 

  16. Maillard, J. P., Paumard, T., Stolovy, S. R. & Rigaut, F. The nature of the Galactic Center source IRS 13 revealed by high spatial resolution in the infrared. Astron. Astrophys. 423, 155–167 (2004)

    Article  ADS  CAS  Google Scholar 

  17. Portegies Zwart, S. F. et al. The ecology of star clusters and intermediate-mass black holes in the Galactic Bulge. Astrophys. J. 641, 319–326 (2006)

    Article  ADS  Google Scholar 

  18. Brunzendorf, J. & Meusinger, H. The galaxy cluster Abell 426 (Perseus). A catalogue of 660 galaxy positions, isophotal magnitudes and morphological types. Astron. Astrophys. (Suppl.) 139, 141–161 (1999)

    Article  ADS  Google Scholar 

  19. Wegner, G. et al. Redshift-distance survey of early-type galaxies: spectroscopic data. Astron. J. 126, 2268–2280 (2003)

    Article  ADS  CAS  Google Scholar 

  20. Salucci, P., Ashman, K. M. & Persic, M. The dark matter content of spiral galaxies. Astrophys. J. 379, 89–93 (1991)

    Article  ADS  Google Scholar 

  21. Sanders, R. H. & Lowinger, T. The distribution of mass in the galactic nucleus. Astron. J. 77, 292–297 (1972)

    Article  ADS  Google Scholar 

  22. Binney, J. & Tremaine, S. Galactic Dynamics 747 (Princeton Univ. Press, Princeton, New Jersey, 1987)

    MATH  Google Scholar 

  23. 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)

    Article  ADS  CAS  Google Scholar 

  24. 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. 604, 632–652 (2004)

    Article  ADS  Google Scholar 

  25. Freitag, M., Gürkan, M. A. & Rasio, F. A. Runaway collisions in young star clusters—II. Numerical results. Mon. Not. R. Astron. Soc. 368, 141–161 (2006)

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  27. Yungelson, L. R. Evolution of Ultra-Massive Stars and its Implications. Presented at 26th General Assembly of the IAU in Joint Discussion 5. “Calibrating the Top of the Stellar M-L Relation” (Prague, 2006)

  28. Yungelson, L. R., van den Heuvel, E. P. J., Vink, J. S., Portegies Zwart, S. F. & de Koter, A. On the evolution and fate of supermassive stars. Astron. Astrophys. (in the press); preprint available at 〈〉 (2007)

  29. Lee, H. K., Wijers, R. A. M. J. & Brown, G. E. The Blandford-Znajek process as a central engine for a gamma-ray burst. Phys. Rep. 325, 83–114 (2000)

    Article  ADS  Google Scholar 

  30. Leitherer, C. et al. Starburst99: synthesis models for galaxies with active star formation. Astrophys. J. (Suppl.) 123, 3–40 (1999)

    Article  ADS  CAS  Google Scholar 

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This work was supported by the NWO, the Netherlands Research School for Astronomy (NOVA) and by a grant from the National Science Foundation to the Kavli Institute for Theoretical Physics in Santa Barbara.

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Correspondence to Simon F. Portegies Zwart or Edward P. J. van den Heuvel.

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Portegies Zwart, S., van den Heuvel, E. A runaway collision in a young star cluster as the origin of the brightest supernova. Nature 450, 388–389 (2007).

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