Double Shell Burning Phase of Intermediate Mass Population - Part Three - Stars

The evolution of Population III intermediate mass stars of 5, 7, and 9M _⊙ has been studied after the core He-exhaustion phase. There are two energy producing regions within the stars; one is H-burning shell and the other is He-burning shell. During the double shell burning phase, the evolution does not proceed on the asymtotic giant branch and the second dredge-up does not appear, hence, there is no change in the surface composition of the stars. The final state of these stars are important in modelling the galactic evolution.