Estimates of black-hole natal kick velocities from observations of
  low-mass X-ray binaries
  The birth kicks of black holes, arising from asymmetric mass ejection or
neutrino emission during core-collapse supernovae, are of great interest for
both observationally constraining supernova models and population-synthesis
studies of binary evolution. Recently, several efforts were undertaken to
estimate black hole birth kicks from observations of black-hole low-mass X-ray
binaries. We follow up on this work, specifically focussing on the highest
estimated black-hole kick velocities. We find that existing observations do not
require black hole birth kicks in excess of approximately 100 km/s, although
higher kicks are not ruled out.
