  We present an extragalactic perspective of an extended stellar tidal stream
wrapping around the edge-on, spiral galaxy NGC 5907. Our deep images reveal for
the first time a large scale complex of arcing loops that is an excellent
example of how a low-mass satellite accretion can produce an interwoven,
rosette-like structure of debris dispersed in the halo of its host galaxy. The
existence of this structure, which has probably formed and survived for several
Gigayears, confirms that halos of spiral galaxies in the Local Universe may
still contain a significant number of galactic fossils from their hierarchical
formation. To examine the validity of the external accretion scenario, we
present N-body simulations of the tidal disruption of a dwarf galaxy-like
system in a disk galaxy plus dark halo potential that demonstrate that most of
the observed tidal features observed in NGC 5907 can be explained by a single
accretion event. Unfortunately, with no kinematic data and only the projected
geometry of the stream as constraint, the parameters of our model are
considerably degenerate and, for now, must be considered illustrative only.
Interestingly, NGC 5907 has long been considered a prototypical example of a
warped spiral in relative isolation. The presence of an extended tidal stream
challenges this picture and suggests that the gravitational perturbations
induced by the stream progenitor may be the cause for the warp. The detection
of an old, complex tidal stream in a nearby galaxy with rather modest
instrumentation points to the viability of surveys to find extragalactic tidal
substructures around spiral galaxies in the Local Volume (< 15 Mpc) -- with the
prospect of obtaining a census with enough statistical significance to be
compared with cosmological simulations.
