  Deep g'r'i'z' images obtained with the Gemini Multi-Object Spectrograph are
used to investigate the stellar content in the outer regions of the nearby Sc
galaxies NGC 2403 and M33. The red giant branch tip occurs at i' = 23.6 +/- 0.1
in NGC 2403, and the Cepheid and RGB-tip distance scales for this galaxy are in
good agreement. While very young stars are restricted to radii < 10 kpc along
the plane of the disk, a population of bright asymptotic giant branch (AGB)
stars is present out to r = 20 kpc, indicating that star formation occured
outside of the present-day star-forming disk of NGC 2403 during intermediate
epochs. The AGB stars are not in a tidal stream; in fact, the ratio of AGB
stars above the RGB-tip to those below the RGB-tip does not change with radius,
indicating that the bright AGB stars are uniformly mixed with the fainter
stellar content throughout the field. A similar population of bright AGB stars
is detected in the outer regions of M33, and the ratio of bright AGB stars to
stars on the upper RGB is at least as large as that measured in the outer
regions of NGC 2403; thus, an intermediate-age population occurs well outside
of the young star-forming disk of M33.
