Minor galaxy merger

A minor galaxy merger has a small satellite-to-host mass ratio. Its stars are commonly deposited at large host radii after tidal stripping and Chandrasekhar dynamical friction.

For repeated minor galaxy mergers with negligible internal satellite binding energy and zero orbital energy at infinity, parabolic dry-merger energy accounting leaves total energy nearly constant. The virial theorem then gives gravitational radius $R_g\propto M^2$ and mean-square speed proportional to $M^{-1}$. Small satellite mass does not by itself imply negligible internal binding energy.