  We develop a method to compute shakeup effects on photoluminescence in a
Wigner crystal from localized holes. Our method treats the lattice electrons
and the tunneling electron on an equal footing, and uses a quantum-mechanical
calculation of the collective modes that is realistic throughout the Brillouin
zone. We find that shakeup produces a series of sidebands that may be
identified with maxima in the collective mode density of states, and
definitively distinguishes the crystal state from a liquid state. We also find
a shift in the main luminescence peak, that is associated with lattice
relaxation in the vicinity of a vacancy.

Condensed Matter