  We show how to attain super resolution limits for incoherent bosonic sources
using collective measurement strategies. For the case of two point sources
emitting incoherent electromagnetic radiation, our measurement strategy allows
for super-resolution of their separation without requiring prior knowledge of
their intensity centroid. Our measurement strategy relies on exploiting the
symmetry under exchange of N bosonic systems and is equivalent to determining
the spectrum of their density operator. Furthermore, refinements of our
spectrum measurement allow for optimal estimation of further pertinent
parameters, such as the sources relative intensity and their centroid. Finally,
we provide possible experimental schemes that can implement the spectrum
measurement with the use of quantum memories.
