Parent Simulation

Initial Conditions

First we constructed a parent simulation of sufficient size to include thousands of Milky Way sized systems but also of sufficient resolution to construct good Lagrangian volumes. We decided on ~10,000 particles per Milky Way-sized host and a 100 Mpc/h volume. Our level_max=10 , which means our parent simulation’s effective resolution is (2^10)^3 = 1024^3, i.e. a parent particle mass,

mp=8.72×107Mm_p = 8.72 \times 10^7 M_\odot
# parentics.conf
[setup]
boxlength = 100
zstart = 127
levelmin = 10
levelmin_TF = 10
levelmax = 10
padding = 8
overlap = 4
ref_center = 0.5, 0.5, 0.5
ref_extent = 0.2, 0.2, 0.2
align_top = yes
baryons = no
use_2LPT = no
use_LLA = no
periodic_TF = yes
[cosmology]
Omega_m = 0.3175
Omega_L = 0.6825
Omega_b = 0.049
H0 = 67.11
sigma_8 = 0.8344
nspec = 0.9624
transfer = eisenstein
[random]
seed[10] = 34567
[output]
format = gadget2
filename = ./ics
gadget_num_files = 128
[poisson]
fft_fine = yes
accuracy = 1e-5
pre_smooth = 3
post_smooth = 3
smoother = gs
laplace_order = 6
grad_order = 6