The Andromeda galaxy is the closest spiral galaxy, similar to our own.
We propose to completely map M31 at the longest wavelength available on ISO,
i.e. 175 micron using the most sensitive broadband filter of the ISOPHOT
C200 detector.
As a result we expect a far infrared map of unprecedented spatial resolution
extended far beyond the 100 micron IRAS map. This map, obtainable only with
a cooled space telescope, will provide a unique data base for cold dust
investigations. In addition, it complements a huge number of maps made by
generations of astronomers from the Xray and UV down to the radio domain.