  A domain wall (DW) in a nanowire can propagate under a longitudinal magnetic
field by emitting spin waves (SWs). We numerically investigated the properties
of SWs emitted by the DW motion, such as frequency and wavenumber, and their
relation with the DW motion. For a wire with a low transverse anisotropy and in
a field above a critical value, a DW emits SWs to both sides (bow and stern),
while it oscillates and propagates at a low average speed. For a wire with a
high transverse anisotropy and in a weak field, the DW emits mostly stern
waves, while the DW distorts itself and DW center propagates forward like a
drill at a relative high speed.
