I was wondering what the spatial resolution (softening length) of the TNG100 simulation is?
You can find these numbers on the first table of the Project Description page.
I found in the background page that the softening length for stars particles in TNG100-1 at z=0 is 0.74 kpc. Where can I get the softening length for higher redshifts?
Gravitational softenings for stars and DM are in comoving kpc until z=1 after which they are fixed to their z=1 values, such that at z=0 they have half the softening length they would have had if the comoving evolution had been kept. Softenings for gas cells are adaptive, set to 2.5 times the current [comoving] cell radius.
So the softenings at z=1 are the same as at z=0, while for z>1, they become fixed in comoving units (increasingly smaller in physical units towards high redshift).
Thank you Dylan!