Model Chemical Evolution:. Starburst Environment. Once upon a time…. Somewhat big bang started it all. Radiation domination Matter domination Matter gets clumpy: stars and galaxies started forming. 75% Hydrogen 25% Helium. It continues…. Nitrogen, Oxygen, Carbon formed.
Model Chemical Evolution:
Modelling starburst chemical evolution:
Calculates thrown-out elements called yields
Estimates how much of different elements exist.
Has many parameters
Various different masses
SNIa/SNII = 0.15
Initial Metal = 0.004
Eff = 0.15
Six bursts, 2Gyr each.
Comparison: Olofsson’s standard model vs our general model.
Blue = General
Red = Standard
(Example of where our model applies)
Many possible parameters
"Other parameters such as the number and duration of bursts, the effeiciency of the SF and the galactic wind, the slope of the IMF and the production of N, regarding it's primary or secondary origin in massive stars, were varied in order to understand the observed distribution of N/O, C/O, Si/O and [O/Fe] versus O/H in BCGs.”
(O/H) is pretty ok, N/O and C/O to high!
Red: x = 1.35 (Salpeter)
Blue: x = 0.35
Green: x = 0
Red : Rate = 0.15
Blue : Rate = 0
The result of the general model is surprisingly similar to the standard model, since only instantaneous bursts considered.
Supernovae Type Ia and Infall seems reasonable.
The abundance of O/H seems reasonable .
The standard setup seems incomplete to reach the observed abundance-ratios in N/O and C/O.
Possible alternations of parameters like IMF and SNIa/SNII-rate needs justification to fit observational data.
Future work include fitting parameters and further applications and comparison with other type models.