Astron. Astrophys. 339, 409-422 (1998)
We summarize here the main conclusions of this paper.
The comparison of bulge and disk NIR average colors and
mass-to-light ratios to stellar population synthesis models suggests
that the bulges of our sample galaxies are younger and more metal rich
than the disks.
NIR M/L's appear to vary with disk luminosity, consistently with
the trend in the B band, and the
color-luminosity relation. Such a trend can be probably imputed to a
systematic variation of the disk average stellar population with
luminosity, due to a variation of either star formation history or
age, but not of metallicity.
We find no clear evidence to prefer either standard Newtonian
gravitation plus dark halos or modified gravitation, as the quality of
the fits under both paradigms is comparable. The value of the critical
acceleration parameter that best accommodates
the sample as a whole is
The dark halo parameters we obtain for six of our galaxies are
roughly in agreement with the values obtained for late type spirals
from B-band photometry. In particular our data are consistent
with the correlation, already noted by PSS, between dark-to-visible
mass ratio and luminosity.
© European Southern Observatory (ESO) 1998
Online publication: October 21, 1998