  We derive a complete asymptotic expansion of generalized Witten integrals for
Hamiltonian circle actions on arbitrary symplectic manifolds, characterizing
the coefficients in the expansion as integrals over the symplectic strata of
the corresponding Marsden-Weinstein reduced space and distributions on the Lie
algebra. The obtained coefficients involve singular contributions of the
lower-dimensional strata related to numerical invariants of the fixed-point
set.
