Previous abstract Next abstract
Session 48 - Spiral & Field Galaxies.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center
We present JHK surface photometry of 15 highly inclined, late-type (Sab-Sc) spirals and investigate the quantitative effects of dust extinction. Using the J - H, H - K two-color diagram, we compare the color changes along the minor axis of each galaxy to predictions from different models of radiative transfer. Models in which scattering effects are significant and those with more than a small fraction of the light sources located near the edge of the dust distribution do not produce enough extinction to explain the observed color gradients across disk absorption features. The optical depth in dust near the plane as deduced from the color excess depends sensitively on the adopted dust geometry, ranging from \tau = 4 to 15 in the visual band. This suggests that a realistic model of the dust distribution is required, even for infrared photometry, to correct for dust extinction in the bulges of nearly edge-on systems.
Program listing for Tuesday