Yet another agn model
Implements a new mode of accretion:
- Compute the smoothed rho around the BH (as before)
- Compute the smoothed u around the BH
- From these two, compute P and T. Compute the EoS T at this rho,
- Get the subgrid rho and subgrid c
- Use these to compute the Bondi rate.
This is switched on by setting
EAGLEAGN:subgrid_bondi to 1.