Black Hole Formation and Iron Distribution

[nehorlavazapal]

Hi,

does anyone know how much of the universes's iron or carbon has been made in supernovae that formed black holes? Is it 5, 10, 50 % of the iron currently pressent here?

And, if se, do we have any idea how much of the average stars content gets traped in the BH versus the mass of the iron that gets out?

 

[Drakkith]

Interesting question. I'd also like to know where most of the iron in the universe comes from since the most massive stars that produce it inside their cores typically lose it all when the cores collapse into neutron stars or black holes.

 

[Damo ET]

I was under the impression that the heavy elements in nebulae are made in the middle to outer layers that are blown off in the Supernova explosions. The core can collapse into BH or neutron star, and the outer layers (yet to be blown off) are bombarded briefly by vast quantities protons creating all sorts heavier than iron elements as well as the carbon, oxygen ect ect.


Damo

 

[Drakkith]

I was under the impression that the heavy elements in nebulae are made in the middle to outer layers that are blown off in the Supernova explosions. The core can collapse into BH or neutron star, and the outer layers (yet to be blown off) are bombarded briefly by vast quantities protons creating all sorts heavier than iron elements as well as the carbon, oxygen ect ect.


Damo

Yes, that's pretty much correct.

 

[phyzguy]

Don't forget Type-1A supernovae. These do not form black holes or neutron stars, so the entire mass of the supernova is blasted out into space. They typically form on the order of a solar mass of iron group elements, and they are quite common.

 

[Ken G]

Also bear in mind that it doesn't much matter that there is iron in the core, other than the important fact that iron can't fuse and release energy, because the core gets so hot as it collapses that the iron is completely destroyed. A core-collapse pretty much reverses all the fusion processes that made the iron in the first place, so the fusion energy that is released as starlight is just a kind of "debt" that is repaid by gravitational energy during the collapse. But as has been said, new elements are fused in the ejecta (whether core-collapse or type Ia), so that's where the iron comes from.