We present the Synthetic UniveRses For Surveys ( surfs ) simulations , a set of N-body/Hydro simulations of the concordance \Lambda Cold Dark Matter ( \Lambda CDM ) cosmology .
These simulations use Planck cosmology , contain up to 10 billion particles and sample scales & halo masses down to 1 ~ { } { kpc } & 10 ^ { 8 } { M _ { \odot } } .
We identify and track haloes from z = 24 to today using a state-of-the-art 6D halo finder and merger tree builder .
We demonstrate that certain properties of haloes merger trees are numerically converged for haloes composed of \gtrsim 100 particles .
Haloes smoothly grow in mass , V _ { max } , with the mass history characterised by \log M ( a ) \propto \exp \left [ - ( a / \beta ) ^ { \alpha } \right ] where a is the scale factor , \alpha ( M ) \approx 0.8 & \beta ( M ) \approx 0.024 , with these parameters decreasing with decreasing halo mass .
Subhaloes follow power-law cumulative mass and velocity functions , i.e . n ( > f ) \propto f ^ { - \alpha } with \alpha _ { M } = 0.83 \pm 0.01 and \alpha _ { V _ { max } } = 2.13 \pm 0.03 for mass & velocity respectively , independent of redshift , as seen in previous studies .
The halo-to-halo scatter in amplitude is 0.9 dex .
The number of subhaloes in a halo weakly correlates with a halo ’ s concentration c & spin \lambda : haloes of high c & low \lambda have 60 \% more subhaloes than similar mass haloes of low c & high \lambda .
High cadence tracking shows subhaloes are dynamic residents , with 25 \% leaving their host halo momentarily , becoming a backsplash subhalo , and another 20 \% changing hosts entirely , in agreement with previous studies .
In general , subhaloes have elliptical orbits , e \approx 0.6 , with periods of 2.3 ^ { +2.1 } _ { -1.7 } Gyrs .
Subhaloes lose most of their mass at pericentric passage with mass loss rates of \sim 40 \% Gyr ^ { -1 } .
These catalogues will be made publicly available .