  We present observations at 3.6, 4.5, 5.8, 8, 24, 70 & 160um of NGC 205, the
dwarf elliptical companion of M31, obtained with the Spitzer Space Telescope.
The point sources subtracted images at 8 and 24um display a complex and
fragmented infrared emission coming from both very small dust particles and
larger grains. The extended dust emission is spatially concentrated in three
main emission regions, seen at all wavelengths from 8 to 160um. These regions
lie approximately along NGC 205's semi-major axis and range from ~100 to 300 pc
in size. Based on our mid-to-far infrared flux density measurements alone, we
derive a total dust mass estimate of the order of 3.2e4 solar masses, mainly at
a temperature of ~20K. The gas mass associated with this component matches the
predicted mass returned by the dying stars from the last burst of star
formation in NGC 205 (~0.5 Gyr ago). Analysis of the Spitzer data combined with
previous 1.1mm observations over a small central region or "Core'' (18"
diameter), suggest the presence of very cold (~12K) dust and a dust mass about
sixteen times higher than is estimated from the Spitzer measurements alone.
Assuming a gas to dust mass ratio of 100, these two datasets, i.e.with and
without the millimeter observations, suggest a total gas mass range of 3.2e6 to
5e7 solar masses.

Astrophysics