Hydro solver
GRIFFIN (Lahén et al. 2020) is using a modern Smoothed Particle Hydrodynamics
solver (SPHGal, Hu et al. 2014) as well as the meshless finite
mass (MFM) method (Gaburov & Nitadori 2012, Hopkins 2015) as
presented in Steinwandel et al. (2019).
Modeling the interstellar medium
Heating, cooling and the formation/destruction of molecular
H2 and CO is modelled with a non-equilibrium chemical network
(Nelson & Langer 1997, Glover & Mac Low 2007).
Modeling star formation and feedback
GRIFFIN simulations are run at high (solar mass) mass and
spatial (sub-parsec) resolution. Individual massive stars are
realised as fundamental indivisable units with their respective
evolutionary tracks. We also resolve their energy injection by
individual supernovae up to high environmental densities.
Radiation
The simulations include an interstellar ultraviolet radiation field varying
in space and time, with simple implementations for dust and gas shielding and a Strömgren model for photoionization.
Accurate stellar dynamics
The simulations allow for accurate stellar dynamics including post-Newtonian dynamics around black holes and/or
massive stars using a regularised integration
scheme (the KETJU project) as presented in Rantala et al. 2017.
Post-processing
The simulation products are carefully post-processed using various open-source analysis tools
such as PYGAD (Röttgers et al. 2020)
and SKIRT 9
