Astronomy in the Submillimeter and Far Infrared Domains with the Herschel Space Observatory

Herschel will explore the last window on the Universe which has remained until now almost inaccessible to us, namely the Far Infrared to submillimeter wavelength range. This window is perfectly suited to study most of the phases of star formation, which occur at relatively low temperatures. The first step starts in very cold cores, with dust temperatures as low as 6 or 7 K, and proceeds up to the phase of hot corinos, where temperatures reach 100 K. Even larger temperatures, up to a few 1000 K, are found in the outflow shocks caused by the interaction of the outflows emanating from the newly born protostar with the surroundings. All these phases will be studied with the three instruments aboard Herschel: PACS and SPIRE will mostly probe the continuum dust emission, whereas HIFI will be devoted to the study of the molecular emission. This lecture especially focuses on the importance of molecules to study star formation.