Questions of stellar evolution relevant to high energy astrophysics

(Transparencies without blackboard notes)

16.11.2010

Nucleosynthesis: During the life-time of a star, fusion processes produce more and more heavy elements – an onion-skin strukture evolves.

No further fusion beyond Fe !→ no counter-pressure against gravitation→ core collapses until a new equilibrium is reached

Piston in tube analogy:

ratio of specific heats γMonatomic gas: γ = 5/3

Heating to ~keV

Rayleigh-Taylor instability: Light fluid pushes heavy fluid – both fluids seek potential minimum: Interpenetration, turbulences (Rayleigh 1883, Taylor 1950)

Rayleigh-Taylor fingers observed in the Crab Nebula

FLASH code simulationU.Chicago

Next lecture: Pulsars