SCUBA OBSERVATIONS OF EARLY-TYPE GALAXIES

We present SCUBA observations of the emission of 23 E and S0 galaxies at wavelengths of 850 and 450 μm. Four galaxies are detected at 850 μm with signal-to-noise ratios above 3.0, and an additional galaxy, NGC 6524, is detected at both 850 and 450 μm. We use the SCUBA data with published optical and IRAS photometry to construct spectral energy distributions (SEDs) of 15 galaxies extending from 0.36 to 850 μm. Those SEDs are fit by single-temperature dust emission models and by predictions generated by self-consistent Monte Carlo simulations of radiative transfer in three-dimensional distributions of stars and diffuse dust. We discuss implications for the question of cool dust in early-type galaxies, the spatial distribution of diffuse dust, and its ability to generate optical color gradients.