Metallicity and Stellar Formation

[Drakkith]

What does metallicity have to do with stellar formation? Why does low metallicity in stars in the very early universe mean that they needed to be more massive than modern stars to form?

 

[Chronos]

Metallicity plays an important role in collisional heating and cooling during the protostar phase. Primordial gas clouds were virtually metal and dust free [until contaminated by early SNIe's] which promotes formation of extremely massive stars. For a more thorough discussion see: The First Stars - http://arxiv.org/abs/astro-ph/0311019

 

[zhermes]

Thats an excellent article that Chronos linked.
Another note, however: its only partially that pop III stars had to be more massive; its also that they could be more massive, as radiation pressure is less efficient without metal lines---and thus the Eddington limit is weaker.

 

[Drakkith]

Awesome! Thanks Chronos!