| Description |
Early-type galaxies are known to harbor a complex multi-phase interstellar medium. Their dust content, however, remains mysterious. Deep optical imaging surveys have shown that a large number of early-type galaxies possess dust features in a variety of morphological forms. Dust has also been detected in emission in many early-type galaxies using IRAS, ISO and Spitzer observations. Strangely, the dust masses derived from far-infrared observations are typically an order of magnitude larger than those estimated using optical extinction features. This inconsistency in the dust energy balance could suggest the presence of a diffusely distributed dust component that is hard to notice in extinction.We propose PACS and SPIRE imaging of a sample of 11 carefully selected, nearby early-type galaxies with regular and well-defined dust lanes. We will construct panchromatic radiative transfer models for each of these galaxies, based on multi-wavelength optical/NIR images and FIR/submm images. This will enable us to systematically investigate the dust energy balance in dust-lane early-type galaxies, to investigate the amount and the spatial distribution of the dust, to determine the optical properties of the dust, and to test the existence of a diffuse dust component. |
