Physical and Chemical Conditions in Dense comma Warm Instellar Gas comma Part 2 of 2

scientific abstract the warm (100 5000 k), dense (n(h_2) > 10^3 cm^3) interstellar medium is a decisive component of the whole interstellar medium and is closely coupled to key processes like star formation and evolution. it is heated through a wide variety of astrophysically important processes such as shocks of various types, xray irradiation, uv irradiation of interface regions near hii regions, and stellar radiation in the environment of young objects. a rich variety of lines in the ir and submm wavelength region will provide a unique opportunity to investigate the physics, chemistry and interrelation of corresponding phenomena by multiline spectroscopy of various molecules, atoms and ions. however, since allmost all lines cannot be observed from ground based telescopes or even from an airborne observatory (kao) iso would offer the first and only possibility for this investigation. we have selected four classes of objects each representing different processes that heat the gas: (1.) photondominated regions at the interfaces of hii regions (including reflection nebulae), (2.) shocks of various types: strong shocks (jtype) in supernova remnants and moderate or weak shocks (also ctype) in outflow sources, (3.) embedded sources (star formation) where dust is radiatively heated by the central source and gas is heated by dust, and (4.) regions of xray excitation. for each class a small number of prototypical, bright sources and a set of spectral lines in the iso wavelength range has been selected. the set of radiative transitions is selected thus that a maximum of information can be gained for each individual class of objects. much emphasis is placed on the observation of (faint) important lines rather than on mapping because of time constraints by the faintness of some of the crucial lines. using these sources as a kind of templates we also establish a set of crucial lines with which different processe truncat [truncated!, Please see actual data for full text]