Supernova structure and light curves

Abstract

It is concluded from simple assumptions that:

• 1) The SN piston has a relativistic sound speed; a likely realisation of the piston is a magnetic torque that transfers the collapsing core's angular momentum and subsequently converts into relativistic pair plasma.

• 2) In pressure contact with the pair plasma, a SN shell tears into small-filling-factor filaments during the ejection event.

• 3) The exponential tails of SN lightcurves can be explained by photon diffusion: Emission-line photons are trapped in the expanding filamentary shell; they take z years to leak out.

For ejected shell masses ≥ 1 M⊙, these conclusions are not very sensitive to the mass and nuclear chemistry. They are therefore thought to apply to all types of SN, whereby blue-giant progenitors yield smaller (bolometric, time-integrated) luminosities than redgiant progenitors.