On the Thermally Pulsing Asymptotic Giant Branch Contribution to the
  Light of Nearby Disk Galaxies
  The study of the luminosity contribution from thermally pulsing asymptotic
giant branch (TP-AGB) stars to the stellar populations of galaxies is crucial
to determine their physical parameters (e.g., stellar mass and age). We use a
sample of 84 nearby disk galaxies to explore diverse stellar population
synthesis models with different luminosity contributions from TP-AGB stars. We
fit the models to optical and near-infrared (NIR) photometry, on a
pixel-bypixel basis. The statistics of the fits show a preference for a
low-luminosity contribution (i.e., high mass-to-light ratio in the NIR) from
TP-AGB stars. Nevertheless, for 30 percent to 40 percent of the pixels in our
sample a high-luminosity contribution (hence low mass-to-light ratio in the
NIR) from TP-AGB stars is favored. According to our findings, the mean TP-AGB
star luminosity contribution in nearby disk galaxies may vary with Hubble type.
This may be a consequence of the variation of the TP-AGB mass-loss rate with
metallicity, if metal-poor stars begin losing mass earlier than metal-rich
stars, because of a pre-dust wind that precedes the dust-driven wind.
