We propose to observe a sample of elliptical galaxies belonging to rich
 clusters, in order to study the effect of ram-pressure stripping on the
 cold component of the interstellar medium. Galaxies moving in dense
 environments are expected to be stripped, either through encounters
 with other galaxies, or by interaction with the intracluster medium
 The ram-pressure effect causes removal of interstellar medium material
 from the outer parts of the galaxy, while the gas and dust surviving
 in the innermost parts are expected to be warmer and denser. Moreover,
 the stripping can influence the properties of radio sources in
 cluster galaxies.
 The best candidates for the study of ram-pressure stripping effects
 are cluster radio galaxies showing a tailed morphology, since the
 radio structure of these objects demonstrates the interaction of the
 parent galaxy with the intergalactic medium. To avoid a bias toward
 radio emitting galaxies, we also request to observe a sample of
 radio-quiet cluster galaxies, moving at high speed with respect to the
 cluster mean velocity, i.e. objects where the stripping effects are
 expected to be strong. With these observations we will be able to
 study the process of stripping of the cold gas and dust, and its
 possible correlation with the radio emission.
 We request fotometric observations at 3 wavelengths, to derive the
 mass and temperature of the dust, and observations at 12 micron to get
 information on the spatial distribution of the dust with respect  to
 the galaxy and, for radio source, the radio structure.