SN 2008D: A Wolf-Rayet Explosion Through a Thick Wind
Abstract
Supernova (SN) 2008D/XRT 080109 is considered to be the only direct detection of a shock breakout from a regular SN to date. While a breakout interpretation was favored by several papers, inconsistencies remain between the observations and current SN shock breakout theory. Most notably, the duration of the luminous X-ray pulse is considerably longer than expected for a spherical breakout through the surface of a type Ibc SN progenitor, and the X-ray radiation features, mainly its flat spectrum and its luminosity evolution, are enigmatic. We apply a recently developed theoretical model for the observed radiation from a Wolf-Rayet SN exploding through a thick wind and show that it naturally explains all of the observed features of SN 2008D X-ray emission, including the energetics, the spectrum, and the detailed luminosity evolution. We find that the inferred progenitor and SN parameters are typical for an exploding Wolf-Rayet. A comparison of the wind density found at the breakout radius and the density at much larger radii, as inferred by late radio observations, suggests an enhanced mass-loss rate taking effect about 10 days prior to the SN explosion. This finding joins accumulating evidence for a possible late phase in the stellar evolution of massive stars, involving vigorous mass loss a short time before the SN explosion.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2014
- DOI:
- arXiv:
- arXiv:1403.3400
- Bibcode:
- 2014ApJ...788L..14S
- Keywords:
-
- radiation mechanisms: non-thermal;
- stars: mass-loss;
- stars: Wolf-Rayet;
- supernovae: general;
- supernovae: individual: 2008D;
- X-rays: bursts;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 5 pages, 1 figure, submitted to apjL
