Evolution of subhalo orbits in a smoothly growing host halo potential

The orbital parameters of dark matter (DM) subhaloes play an essential role in determining their mass-loss rates and overall spatial distribution within a host halo. Haloes cosmological simulations grow by combination relatively smooth accretion more violent mergers, both processes will modify subhalo orbits. To isolate the impact growth halo from other relevant mechanisms, we study evolution using numerical calculations which are modelled as massless particles orbiting time-varying spherical potential. We find that radial action orbit decreases over first few orbits, indicating response to is not adiabatic during this phase. orbits can shrink factor $\sim$1.5 Subsequently, well conserved contraction slows down. propose model accurately describing evolution. Given these results, consider population identified high-resolution simulations. it consistent with having been accreted at z < 3, any earlier unresolved also discuss tidal stripping formation scenario for NGC1052-DF2, ultra diffuse galaxy significantly lacking DM, its expected DM mass could be observational constraints if progenitor was early enough, > 1.5, although should still rare object.