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A non-spherical core in the explosion of supernova SN 2004dj

Abstract

An important and perhaps critical clue to the mechanism driving the explosion of massive stars as supernovae is provided by the accumulating evidence for asymmetry in the explosion. Indirect evidence comes from high pulsar velocities1, associations of supernovae with long-soft γ-ray bursts2,3, and asymmetries in late-time emission-line profiles4. Spectropolarimetry provides a direct probe of young supernova geometry, with higher polarization generally indicating a greater departure from spherical symmetry5,6. Large polarizations have been measured for ‘stripped-envelope’ (that is, type Ic; ref. 7) supernovae, which confirms their non-spherical morphology8,9; but the explosions of massive stars with intact hydrogen envelopes7,10 (type II-P supernovae) have shown only weak polarizations at the early times observed11,12. Here we report multi-epoch spectropolarimetry of a classic type II-P supernova that reveals the abrupt appearance of significant polarization when the inner core is first exposed in the thinning ejecta (90 days after explosion). We infer a departure from spherical symmetry of at least 30 per cent for the inner ejecta. Combined with earlier results, this suggests that a strongly non-spherical explosion may be a generic feature of core-collapse supernovae of all types, where the asphericity in type II-P supernovae is cloaked at early times by the massive, opaque, hydrogen envelope.

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Figure 1: Intrinsic polarization of SN 2004dj during the photospheric phase, with day since explosion indicated.
Figure 2: Light curve and continuum polarization of SN 2004dj.

References

  1. Chatterjee, S. et al. Getting its kicks: A VLBA parallax for the hyperfast pulsar B1508 + 55. Astrophys. J. 630, L61–L64 (2005)

    ADS  Article  Google Scholar 

  2. Galama, T. J. et al. An unusual supernova in the error box of the gamma-ray burst of 25 April 1998. Nature 395, 670–672 (1998)

    ADS  CAS  Article  Google Scholar 

  3. Matheson, T. et al. Photometry and spectroscopy of GRB 030329 and its associated supernova 2003dh: The first two months. Astrophys. J. 599, 394–407 (2003)

    ADS  CAS  Article  Google Scholar 

  4. Mazzali, P. A. et al. An asymmetric, energetic type Ic supernova viewed off-axis and a link to gamma-ray bursts. Science 308, 1284–1287 (2005)

    ADS  CAS  Article  PubMed  Google Scholar 

  5. Shapiro, P. R. & Sutherland, P. G. The polarization of supernova light—A measure of deviation from spherical symmetry. Astrophys. J. 263, 902–924 (1982)

    ADS  Article  Google Scholar 

  6. Höflich, P. Asphericity effects in scattering dominated photospheres. Astron. Astrophys. 246, 481–489 (1991)

    ADS  Google Scholar 

  7. Filippenko, A. V. Optical spectra of supernovae. Annu. Rev. Astron. Astrophys. 35, 309–355 (1997)

    ADS  CAS  Article  Google Scholar 

  8. Leonard, D. C. & Filippenko, A. V. in Supernovae as Cosmological Lighthouses (eds Turatto, M., Benetti, S., Zampieri, L. & Shea, W.) 330–336 (ASP, San Francisco, 2005)

    Google Scholar 

  9. Wang, L., Baade, D., Höflich, P. A. & Wheeler, J. C. Spectropolarimetry of the Type Ic supernova SN 2002ap in M74: More evidence for asymmetric core collapse. Astrophys. J. 592, 457–466 (2003)

    ADS  CAS  Article  Google Scholar 

  10. Leonard, D. C. et al. The distance to SN 1999em in NGC 1637 from the expanding photosphere method. Publ. Astron. Soc. Pacif. 114, 35–64 (2002)

    ADS  Article  Google Scholar 

  11. Leonard, D. C., Filippenko, A. V., Ardila, D. R. & Brotherton, M. S. Is it round? Spectropolarimetry of the Type II-P supernova 1999em. Astrophys. J. 553, 861–885 (2001)

    ADS  CAS  Article  Google Scholar 

  12. Leonard, D. C. & Filippenko, A. V. Spectropolarimetry of the Type II supernovae 1997ds, 1998A, and 1999gi. Publ. Astron. Soc. Pacif. 113, 920–936 (2001)

    ADS  Article  Google Scholar 

  13. Nakano, S., Itagaki, K., Bouma, R. J., Lehky, M. & Hornoch, K. Supernova 2004dj in NGC 2403. IAU Circ. 8377 (2004)

  14. Patat, F., Benetti, S., Pastorello, A., Filippenko, A. V. & Aceituno, J. Supernova 2004dj in NGC 2403. IAU Circ. 8378 (2004)

  15. Freedman, W. L. et al. Final results from the Hubble Space Telescope key project to measure the Hubble constant. Astrophys. J. 553, 47–72 (2001)

    ADS  Article  Google Scholar 

  16. Eastman, R. G., Woosley, S. E., Weaver, T. A. & Pinto, P. A. Theoretical light curve of a Type II-P supernova. Astrophys. J. 430, 300–310 (1994)

    ADS  CAS  Article  Google Scholar 

  17. Höflich, P., Wheeler, J. C., Hines, D. C. & Trammell, S. R. Analysis of the polarization and flux spectra of SN 1993. J. Astrophys. J. 459, 307–321 (1996)

    ADS  Article  Google Scholar 

  18. Jeffery, D. J. Analysis of SN 1987A polarimetry. Astrophys. J. 375, 264–287 (1991)

    ADS  Article  Google Scholar 

  19. Leonard, D. C., Li, W., Filippenko, A. V., Foley, R. J. & Chornock, R. Evidence for spectropolarimetric diversity in Type Ia supernovae. Astrophys. J. 632, 450–475 (2005)

    ADS  CAS  Article  Google Scholar 

  20. Wheeler, J. C., Meier, D. L. & Wilson, J. R. Asymmetric supernovae from magnetocentrifugal jets. Astrophys. J. 568, 807–819 (2002)

    ADS  CAS  Article  Google Scholar 

  21. Maeda, K. et al. Explosive nucleosynthesis in aspherical hypernova explosions and late-time spectra of SN 1998bw. Astrophys. J. 565, 405–412 (2002)

    ADS  CAS  Article  Google Scholar 

  22. Höflich, P. A., Baade, D., Khokhlov, A. M., Wang, L. & Wheeler, J. C. in A Massive Star Odyssey: from Main Sequence to Supernova (eds van der Hucht, K. A., Herrero, A. & Esteban, C.) Proc. IAU Symp. 212 387–394 (ASP, San Francisco, 2003)

    Google Scholar 

  23. Elmhamdi, A. et al. Photometry and spectroscopy of the Type IIP SN 1999em from outburst to dust formation. Mon. Not. R. Astron. Soc. 338, 939–956 (2003)

    ADS  CAS  Article  Google Scholar 

  24. Chugai, N. N. et al. Optical observations of the Type IIP supernova 2004dj: Evidence for the asymmetry of 56Ni ejecta. Astron. Lett. 31, 792–805 (2005)

    ADS  CAS  Article  Google Scholar 

  25. Höflich, P. A., Khokhlov, A. & Wang, L. in 20th Texas Symp. on Relativistic Astrophysics (eds Wheeler, J. C. & Martel, H.) 459–471 (AIP, New York, 2001)

    Google Scholar 

  26. Höflich, P. A. Remarks on the polarization observed in SN 1993J. Astrophys. J. 440, 821–829 (1995)

    ADS  Article  Google Scholar 

  27. Wang, X. et al. The progenitor of SN 2004dj in a star cluster. Astrophys. J. 626, L89–L92 (2005)

    ADS  Article  Google Scholar 

  28. Li, W., Van Dyk, S. D., Filippenko, A. V. & Cuillandre, J.-C. On the progenitor of the Type II SN 2004et in NGC 6946. Publ. Astron. Soc. Pacif. 117, 121–131 (2005)

    ADS  Article  Google Scholar 

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

    ADS  Article  Google Scholar 

  30. Maeder, A. & Conti, P. S. Massive star populations in nearby galaxies. Annu. Rev. Astron. Astrophys. 32, 227–275 (1994)

    ADS  Article  Google Scholar 

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Acknowledgements

We thank D. Kasen for discussions. Support for this research was provided by the National Science Foundation, NASA, and the Sylvia and Jim Katzman Foundation. A.V.F. is grateful for a Miller Research Professorship at UC Berkeley, during which part of this work was completed.

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Correspondence to Douglas C. Leonard.

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Leonard, D., Filippenko, A., Ganeshalingam, M. et al. A non-spherical core in the explosion of supernova SN 2004dj. Nature 440, 505–507 (2006). https://doi.org/10.1038/nature04558

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