Nearby galaxy is a “fossil” from the early universe

On 15/05/2014 5:58 PM, Steve Willner wrote:
I'm not an expert on this, but as far as I can gather: supermassive
Pop III stars (no longer present) produce predominantly alpha
elements, massive core collapse SNe are needed to produce r-process
elements
http://en.wikipedia.org/wiki/R-process

In article ,
Yousuf Khan writes:
Are you saying the original Pop III stars only produced Alpha particles
(i.e. Helium) when they exploded?

Alpha _elements_ are those with even atomic numbers and atomic masses
a multiple of four: carbon, oxygen, magnesium, etc.

So R-process supernovas would have produced more heavier-than-iron
elements, while Type Ia supernovas would have produced mostly iron?

As I wrote, I'm not an expert and haven't looked up the proper
numbers. I gather, however, that the Ia fail to produce much of
anything beyond the iron group, whereas the core collapse SNe produce
R-process elements in addition to the iron group. I'd be surprised
if they produce a total amount of R-process elements anywhere near
amount of iron they produce, but the proportion is higher.

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