  Deep images of the Centaurus and Coma clusters reveal two spectacular arcs of
diffuse light that stretch for over 100 kpc, yet are just a few kpc wide. At a
surface brightness of m_b \sim 27-28th arcsec^-2, the Centaurus arc is the most
striking example known of structure in the diffuse light component of a rich
galaxy cluster. We use numerical simulations to show that the Centaurus feature
can be reproduced by the tidal debris of a spiral galaxy that has been tidally
disrupted by the gravitational potential of NGC 4709. The surface brightness
and narrow dimensions of the diffuse light suggest that the disk was
co-rotating with its orbital path past pericentre. Features this prominent in
clusters will be relatively rare, although at fainter surface brightness levels
the diffuse light will reveal a wealth of structure. Deeper imaging surveys may
be able to trace this feature for several times its presently observed extent
and somewhere along the tidal debris, a fraction of the original stellar
component of the disk will remain bound, but transformed into a faint
spheroidal galaxy. It should be possible to confirm the galactic origin of the
Centaurus arc by observing planetary nebulae along its length with redshifts
close to that of NGC 4709.
