  We present precise measurements of the optical Feshbach resonances (OFRs) of
$^{174}$Yb atoms for the intercombination transition. We measure the
photoassociation (PA) spectra of a pure $^{174}$Yb Bose-Einstein condensate,
and determine the dependence of OFRs to PA laser intensities and frequencies
for four least bound vibrational levels near the intercombination transition.
We confirm that our measurements are consistent with the temporal decay of a
BEC subjected to a PA beam in the vicinity of the fourth vibrational level from
the dissociation limit.
