PPT Slide
Galaxy Formation And Evolution
Metallicity is defined as:
Hydrogen is primordial, and the majority of Helium was produced in the first 3 minutes after the Big Bang.
Nearly everything else was produced in the interior of stars.
The cycle of reprocessing of the elements over time, and the return of those elements to the interstellar medium (ISM) gives rise to the currently observed metallicity distribution of stars….