Alain Abergel 1, J.P. Bernard 1, F. Boulanger 2, F.X. Désert 1, M.A. Miville-Deschênes 1, J.-L. Puget 1, L. Nordh 2, G. Olofsson 2, S. Bontemps 2, A. A. Kaas 2, M. Huldtgren 2, E. Falgarone 3, M. Perault 3, P. André 4, & A. Bacmann 4
1 Institut d'Astrophysique Spatiale, Université Paris-Sud, Bât. 121, 91405 Orsay Cedex, France
2 Stockholm Observatory, S-133 36 Saltsjöbaden, Sweden
3 Radioastronomie Millimétrique, Ecole Normale Supérieure, Paris, France
4 Service d'Astrophysique, CEA, 91191, Gif-Sur-Yvette Cedex, France
Large scale mapping of several regions in the interstellar medium have
been conducted with the long-wavelength channel of ISOCAM in two
broad-band filters (5-8.5 and 12-18 
m). The angular resolution
(3-6
)
and sensitivity of
the instrument have allowed to reveal
the extended mid-IR emission of dust in a wide range of illuminations
and densities, and at different stages of the evolution before and
after stellar formation.
Structures in the emission of faint cirrus have been discovered. The observations of illuminated edges of molecular clouds gives new constraints on the penetration of UV radiations toward dense clouds. The emission of dust heated by bright stars recently formed and still embedded reveals the spatial structure of parental cocoons. Dense cores likely stellar progenitors are seen as sharp and deep absorption structures against a diffuse background emission. New constraints on their density structure and extinction properties can be derived.