Help me on the timeline of star formation in the early Universe

[BWV]

Referencing this posted on the Webb thread:
https://www.quantamagazine.org/two-...ce-telescope-is-reshaping-astronomy-20220725/

So will they able to do spectroscopy on GLASS-z13, the galaxy dating 300M after the big bang? Do they expect to see any heavier elements in a galaxy that old? When do models suggest the first heavier elements to have formed? Seems like seeing O after only 700M years implies some fairly short-lived supermassive stars

Also, the Wikipedia article on the expansion of the universe lists first stars about 400MY after the Big Bang, but the article references the GLASS-z13 galaxy dating 300MY after?

 

[Dragrath]

This is a bit tricky as there are model dependencies which effect when and how exactly stars first form and what properties they will have. Additionally we can't assume all such population III stars formed at the same time between different galaxies


There is also an assumption dependent relationship between galaxy redshift and distance which only holds if spacetime is homogeneous and anisotropic at some relevant length scale. If there is no longer a direct linear relationship between redshift and distance then the age of that galaxy would be younger so you can think of that date as more of a upper bound on age, i.e. it could be younger but probably not older than that. Everything depends on model assumptions and measurement uncertainty and popular science articles are notoriously bad with either of those concepts making them effectively close to worthless

 

[phyzguy]

Very massive stars only live a few million years before they go supernova and spew heavier elements into the interstellar medium. We don't know exactly when the first stars began to form, that's one of the things we hope to learn more about from Webb. But as soon as the first stars began to form, it is only a few million years later that we will begin to see stars containing elements like oxygen.