  We report the observation of a pairing in a number polarized two-component
gas of atomic fermions. Beyond a critical polarization, the gas separates into
a superfluid paired core surrounded by a shell of normal unpaired fermions. The
critical polarization diminishes with decreasing attractive interaction. We
also measure the parameter \beta = 0.54 (5) describing the universal energy of
a strongly interacting Fermi gas, and find good agreement with most recent
theory. These results are relevant to predictions of exotic new phases of quark
matter and of strongly magnetized superconductors.
