A Spectroscopically Normal Type Ic Supernova from a Very Massive Progenitor
Abstract
We present observations of the Type Ic supernova (SN Ic) 2011bm spanning a period of about one year. The data establish that SN 2011bm is a spectroscopically normal SN Ic with moderately low ejecta velocities and with a very slow spectroscopic and photometric evolution (more than twice as slow as SN 1998bw). The Pan-STARRS1 retrospective detection shows that the rise time from explosion to peak was ~40 days in the R band. Through an analysis of the light curve and the spectral sequence, we estimate a kinetic energy of ~7-17 foe and a total ejected mass of ~7-17 M ⊙, 5-10 M ⊙ of which is oxygen and 0.6-0.7 M ⊙ is 56Ni. The physical parameters obtained for SN 2011bm suggest that its progenitor was a massive star of initial mass 30-50 M ⊙. The profile of the forbidden oxygen lines in the nebular spectra shows no evidence of a bi-polar geometry in the ejected material.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2012
- DOI:
- 10.1088/2041-8205/749/2/L28
- arXiv:
- arXiv:1203.1933
- Bibcode:
- 2012ApJ...749L..28V
- Keywords:
-
- supernovae: general;
- supernovae: individual: SN 2011bm;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 3 Figures - 2 Tables - Accepted for publication in ApJL