Supernova Shock Breakout

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A Super Nova Shock Breakout describes the penetration of the radiation , which the shock wave precedes, by the photosphere of a star whose core in a core-collapse Super Nova collapses is. An intense flash in the range of ultraviolet and X-rays is emitted over a very short period of a few to a few hundred seconds . The Supernova Shock Breakout is the first electromagnetic radiation that an observer can perceive from a supernova. That is why a supernova shock breakout is also known as a radiative precursor . Supernova shock breakouts have been detected in the supernovae SN 2008D and SNLS-04D2dc.

Core collapse supernovae arise when the degeneracy pressure in the core of a developed star can no longer keep the gravitational forces in balance. In the inverse beta decay , the electrons then fuse with the protons , and the star's nucleus transforms into a proton neutron star . The material that continues to fall bounces off the surface of the protoneutron star and runs outwards as a shock wave. The shock wave reaches such high densities that it absorbs the neutrinos produced during the inverse beta decay and is thereby accelerated. The star matter is heated when it passes through the shock wave and accelerated to a few percent of the speed of light . Radiation from the shock wave diffuses through the star a little faster than the shock wave itself and briefly heats the photosphere to temperatures of 10 5 Kelvin .  

Observations of supernova shock breakouts can be used to analyze the predecessor star of a core collapse supernova:

  • the duration of the supernova shock breakout depends heavily on the aspherical shape of the star, which can be caused by rapid rotation or tidal forces in close binary stars .
  • the luminosity of Supernova Shock Breakouts depends on:
    • the density structure of the star
    • the energy released during core collapse
    • the chemical composition
    • the radius.
  • If the signal is delayed and emitted in the optical at low wavelengths , the forerunner star of the supernova has gone through episodes with strong stellar winds like Wolf-Rayet stars or luminous blue variables .

Individual evidence

  1. ^ Keiichi Maeda: Probing Shock Breakout and Progenitors of Stripped-Envelope Supernovae through Their Early Radio Emissions . In: Astrophysics. Solar and Stellar Astrophysics . 2012, arxiv : 1209.1904v2 .
  2. ↑ Kevin Schawinski et al .: Supernova Shock Breakout from a Red Supergiant . In: Astrophysics. Solar and Stellar Astrophysics . 2008, arxiv : 0803.3596v3 .
  3. ↑ Sean M. Couch, David Pooley, J. Craig Wheeler, Milos Milosavljevic: Aspherical Supernova Shock Breakout and the Observations of Supernova 2008D . In: Astrophysics. Solar and Stellar Astrophysics . 2010, arxiv : 1007.3693v2 .
  4. ↑ Ehud Nakar, Re'em Sari: Early supernovae light-curves following the shock-breakout . In: Astrophysics. Solar and Stellar Astrophysics . 2010, arxiv : 1004.2496v2 .
  5. ↑ Shmuel Balberg, Abraham Loeb: Supernova Shock Breakout Through a Wind . In: Astrophysics. Solar and Stellar Astrophysics . 2011, arxiv : 1101.1489v3 .