  We study electron tunneling from a tip or a lead into an interacting quantum
wire described by Luttinger liquid theory. Within a WKB-type approach, the
Coulomb interaction between the wire and the tunneling electrons, as well as
the finite traversal time are taken into account. Although the static image
potential is only logarithmically suppressed against the bare Coulomb
interaction, the dynamic image potential is not strong enough to alter
power-law exponents entering the tunneling density of states.
