dynamical friction in the MW2014 potential
UnitMass_in_cgs: 1.988409870698051e+43 # 10^10 Solar masses UnitLength_in_cgs: 3.0856775814913673e+21 # kpc UnitVelocity_in_cgs: 1e5 # 1 km / s in cm/s
UnitMass_in_cgs: 1.988409870698051e+43 # 10^10 Solar masses UnitLength_in_cgs: 3.0856775814913673e+21 # kpc UnitVelocity_in_cgs: 1e5 # 1 km / s in cm/s