Zones

I have a couple of thoughts about the engine. It is relatively simple in concept. It consists of zones. People should be able to choose how many zones they want from 1 to 1000 (?). The zones keep track of their metallicity and imprint it on any stars formed therein. They have a size that can determine their surface density and thus star formation rate. They can have gas flow in or out during each timestep. There is a question about what the metallicity of the inflowing and outflowing gas is. They are enriched by evolving stars every time step. Where this becomes complicated is how you link the zones together. Gas generally should flow inwards through the disk. Gas could be accreted from multiple sources:

• pristine cosmic gas (only at the disc boundary zone(s)?)
• halo gas
• other disk zones

One could imagine having a linked list that tells a zone where it should send its gas. There is a zone for the halo gas that has a different geometry (sphere, instead of annulus), and a source.

The “metallicity” needs to be generalizable to include as many different elements as the user wants. This would likely be a dictionary so that users could say

star[‘Mg’]

Stars have positions (radii), masses and metal contents. Their mass evolves with time. There will be a parameter that determines how much the stars move with time (radial migration).

The part I want to contribute to the code is the simulation input. The simulation determines how much gas inflow and outflow there is, but this is hard to get out of the simulation. One needs very high time resolution. I have not ever tried to do this analysis.

There will have to be a parameter file, probably a config type file to use the python config (Configuration??) module.