  Selecting centrally quiescent galaxies from the Sloan Digital Sky Survey
(SDSS) to create high signal-to-noise (>100) stacked spectra with minimal
emission line contamination, we accurately and precisely model the central
stellar populations of barred and unbarred quiescent disk galaxies. By
splitting our sample by redshift, we can use the fixed size of the SDSS fiber
to model the stellar populations at different radii within galaxies. At
0.02<z<0.04, the SDSS fiber radius corresponds to ~1 kpc, which is the typical
half-light radii of both classical bulges and disky pseudobulges. Assuming that
the SDSS fiber primarily covers the bulges at these redshifts, our analysis
shows that there are no significant differences in the stellar populations,
i.e., stellar age, [Fe/H], [Mg/Fe], and [N/Fe], of the bulges of barred vs.
unbarred quiescent disk galaxies. Modeling the stellar populations at different
redshift intervals from z=0.020 to z=0.085 at fixed stellar masses produces an
estimate of the stellar population gradients out to about half the typical
effective radius of our sample, assuming null evolution over this ~1 Gyr epoch.
We find that there are no noticeable differences in the slopes of the
azimuthally averaged gradients of barred vs. unbarred quiescent disk galaxies.
These results suggest that bars are not a strong influence on the chemical
evolution of quiescent disk galaxies.
