ORIGIN AND EVOLUTION OF DUST IN ELLIPTICAL GALAXIES: PART 3 OF 3 ANALYSIS OF INFRARED CONTINUUM EMISSION FROM 5 TO 200 M.

we propose to measure the continuum emission between 5 microns and 200 microns from a sample of 35 nearby elliptical galaxies selected to cover a wide range of properties. the goals of this work are: (1) to measure the properties of interstellar dust in elliptical galaxies (grain size spectrum, long wavelength emissivity): (2) to measure the rate of injection of dust into the ism by dying stars: and (3) to measure the total interstellar dust content and its distribution. together, these observations allow an investigation of the origin and evolution of the cold ism in ellipticals. in addition, we will use millimeter and radio wavelength observations of interstellar gas to measure the gas to dust ratio and x ray data to examine the balances among hot gas, cold gas, and star formation. finally, the amount of ism in a small sample of radio elliptical galaxies will be measured, plus the strength and properties of infrared emission from the active nucleus. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]