# Define the parameters of the zoom region ZoomRegion: region_pad_factor: 1.1 # How much larger the zoom region will be than the high res particle distribution in the ICs? zoom_top_level_cells: 16 # How many top level cells should the zoom region be resolved with? (superceeds Scheduler:max_top_level_cells which is unused when a zoom region is turned on) bkg_top_level_cells: 22 # How many cells should the background be resolved with? region_buffer_cell_ratio: 2 # How many buffer cells should be in the zoom region? (if 0 buffer cells are ignored) neighbour_max_tree_depth: 2 # The depth of the cell trees neighbouring the zoom region bkg_subdepth_diff_grav: 3 # The minimum difference between the leaf depth and the task depth for background cells. # Define the system of units to use internally. InternalUnitSystem: UnitMass_in_cgs: 1.98841e43 # 10^10 M_sun in grams UnitLength_in_cgs: 3.08567758e24 # Mpc in centimeters UnitVelocity_in_cgs: 1e5 # km/s in centimeters per second UnitCurrent_in_cgs: 1 # Amperes UnitTemp_in_cgs: 1 # Kelvin # Cosmological parameters Cosmology: h: 0.6777 # Reduced Hubble constant a_begin: 0.9090909 # Initial scale-factor of the simulation a_end: 1.0 # Final scale factor of the simulation Omega_cdm: 0.2587481 # Cold Dark Matter density parameter Omega_lambda: 0.693 # Dark-energy density parameter Omega_b: 0.0482519 # Baryon density parameter # Parameters governing the time integration TimeIntegration: time_begin: 0. # The starting time of the simulation (in internal units). time_end: 1e-2 # The end time of the simulation (in internal units). dt_min: 1e-10 # The minimal time-step size of the simulation (in internal units). dt_max: 1e-2 # The maximal time-step size of the simulation (in internal units). # Parameters governing the snapshots Snapshots: basename: zoom_example scale_factor_first: 0.92 # Scale-factor of the first snaphot (cosmological run) time_first: 0.01 # Time of the first output (non-cosmological run) (in internal units) delta_time: 1.10 # Time difference between consecutive outputs (in internal units) compression: 1 # Parameters governing the conserved quantities statistics Statistics: scale_factor_first: 0.92 # Scale-factor of the first stat dump (cosmological run) time_first: 0.01 # Time of the first stat dump (non-cosmological run) (in internal units) delta_time: 1.05 # Time between statistics output # Parameters for the self-gravity scheme Gravity: eta: 0.025 # Constant dimensionless multiplier for time integration. MAC: adaptive epsilon_fmm: 0.001 theta_cr: 0.7 # Opening angle (Multipole acceptance criterion) mesh_side_length: 512 comoving_DM_softening: 0.0026994 # Comoving DM softening length (in internal units). max_physical_DM_softening: 0.0007 # Max physical DM softening length (in internal units). # Parameters related to the initial conditions InitialConditions: file_name: zoom_ics.hdf5 periodic: 1 cleanup_h_factors: 1 # Remove the h-factors inherited from Gadget cleanup_velocity_factors: 1 # Remove the sqrt(a) factor in the velocities inherited from Gadget # Parameters for the hydrodynamics scheme SPH: resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel). h_min_ratio: 0.01 # Minimal smoothing length in units of softening. h_max: 0.5 # Maximal smoothing length in co-moving internal units. CFL_condition: 0.2 # Courant-Friedrich-Levy condition for time integration. minimal_temperature: 100.0 # (internal units) initial_temperature: 268.7 # (internal units) particle_splitting: 1 # Particle splitting is ON particle_splitting_mass_threshold: 7e-4 # (internal units, i.e. 7e6 Msun ~ 4x initial gas particle mass) convert_particles_at_h_max: 1 # Flag for whether to convert SPH particles which reach h_max to dark matter (this can help with long running neighbour searches by removing non-physical particles limited by h_max)