Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T18:29:10.989Z Has data issue: false hasContentIssue false

Asymmetry in Supernovae

Published online by Cambridge University Press:  05 September 2012

Keiichi Maeda*
Affiliation:
Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan 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.

Asymmetry in the innermost part of the supernova (SN) ejecta is a key to understanding their explosion mechanisms. Late-time spectroscopy is a powerful tool to investigate the issue. We show what kind of geometry is inferred for different types of SNe – core-collapse SNe Ib/c, those associated with Gamma-Ray Bursts (GRBs), and thermonuclear SNe Ia –, and discuss implications for the explosion mechanisms, observational diversities, and cosmological applications. For SNe Ib/c, the data show the clear deviation from spherical symmetry, and they are most consistent with the bipolar-type explosion as the characteristic geometry. Detailed modeling of optical emissions from SN 1998bw associated with GRB980425 indicates that this SN was in the extreme end of the bipolar explosion, suggesting that the explosion mechanisms of canonical SNe Ib/c and GRB-SNe are different. The situation is different for SNe Ia. Late-time spectra indicate the deviation from spherical symmetry, but for SNe Ia the explosion is asymmetric between two hemispheres, i.e., one-sided explosions. The diversities arising from different viewing directions can nicely explain (a part of) observational diversities of SNe Ia, and correcting this effect may improve the standard-candle calibration of SNe Ia for cosmology.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

Benetti, S., et al. 2005, ApJ, 623, 1011CrossRefGoogle Scholar
Blondin, J. M., Mezzacappa, A., & DeMarino, C.ApJ, 584, 971CrossRefGoogle Scholar
Blondin, J. M. & Mezzacappa, A. 2007, Nature, 445, 58CrossRefGoogle Scholar
Filippenko, A. V. 1997, ARAA, 35, 309CrossRefGoogle Scholar
Folatelli, G., et al. 2010, AJ, 139, 120CrossRefGoogle Scholar
Galama, T. J., et al. 1998, Nature, 395, 670CrossRefGoogle Scholar
Hjorth, J., et al. 2003, Nature, 423, 847CrossRefGoogle Scholar
Iwakami, W., et al. 2009, ApJ, 700, 232CrossRefGoogle Scholar
Iwamoto, K., et al. 1998, Nature, 395, 672CrossRefGoogle Scholar
Kasen, D., Röpke, F., & Woosley, S. E. 2009, Nature, 460, 869CrossRefGoogle Scholar
Khokhlov, A. M. 1991, A&A, 245, 114Google Scholar
Kuhlen, M., Woosley, S. E., & Glatznaier, G. A. 2006, ApJ, 640, 407CrossRefGoogle Scholar
Maeda, K., et al. 2002, ApJ, 565, 405CrossRefGoogle Scholar
Maeda, K., et al. 2006a, ApJ, 640, 854CrossRefGoogle Scholar
Maeda, K., Mazzali, P. A., & Nomoto, K. 2006b, ApJ, 645, 1331CrossRefGoogle Scholar
Maeda, K., et al. 2008, Science, 319, 1220CrossRefGoogle Scholar
Maeda, K., et al. 2010a, Nature, 466, 82CrossRefGoogle Scholar
Maeda, K., et al. 2010b, ApJ, 712, 624CrossRefGoogle Scholar
Maeda, K., et al. 2010c, ApJ, 708, 1703CrossRefGoogle Scholar
Maeda, K., et al. 2011, MNRAS, 413, 3075CrossRefGoogle Scholar
Mazzali, P. A., et al. 2001, ApJ, 559, 1047CrossRefGoogle Scholar
Mazzali, P. A., et al. 2005, Science, 308, 1284CrossRefGoogle Scholar
Mazzali, P. A., et al. 2007, Science, 315, 825CrossRefGoogle Scholar
Modjaz, M., et al. 2008, ApJ, 687, L9CrossRefGoogle Scholar
Nomoto, K., Thielemann, F.-K., & Yokoi, K. 1984, ApJ, 286, 644CrossRefGoogle Scholar
Nomoto, K., Iwamoto, K., & Suzuki, T. 1995, Phys. Rep., 256, 173CrossRefGoogle Scholar
Permutter, S., et al. 1999, ApJ, 517, 565CrossRefGoogle Scholar
Phillips, M. M., et al. 1999, AJ, 118, 1766CrossRefGoogle Scholar
Riess, A., et al. 1998, AJ, 116, 1009CrossRefGoogle Scholar
Röpke, F. K., et al. 2012, ApJ, 750, 19CrossRefGoogle Scholar
Sim, S., et al. 2012, MNRAS, 420, 3003CrossRefGoogle Scholar
Takiwaki, T., Kotake, K., & Sato, K. 2009, ApJ, 691, 1360CrossRefGoogle Scholar
Takiwaki, T., Kotake, K., & Suwa, Y. 2012, ApJ, 749, 98CrossRefGoogle Scholar
Tanaka, M., et al. 2007, ApJ, 668, L19CrossRefGoogle Scholar
Taubenberger, S., et al. 2009, MNRAS, 397, 677CrossRefGoogle Scholar
Woosley, S. E. & Weaver, T. A. 1986, ARAA, 24, 205CrossRefGoogle Scholar
Woosley, S. E. 1993, ApJ, 405, 273CrossRefGoogle Scholar