  A state-of-the-art 3D source imaging technique is used to extract the 3D
two-pion source function in central and mid-central Au+Au collisions at
$\sqrt{s_{NN}} = 200$ GeV. The source function indicates a previously
unresolved non-Gaussian tail in the directions of the pion pair transverse
momentum (out) and along the beam (long). Model comparisons give robust
estimates for several characteristics of the emission source, including its
transverse size, its mean proper breakup time $\tau$ and its emission duration
$\Delta\tau$. These estimates are incompatible with the predictions for a first
order phase transition. However, they point to significant relative emission
times which could result from a crossover phase transition.
