Anatomy of Class 0 Protostellar Envelopes in their far-IR Spectrum

During the Science Demonstration Phase, Herschel.s instrumentation has proven its outstanding capabilities to provide an unprecedented view of farinfrered spectra at the 50670 microns regime. We propose a program to obtain spectra with the PACS Intergral Field and SPIRE FTS Spectrometers of luminous and nearby (d<400 pc) lowmass protostellar envelopes previously categorized as Class 0 sources. Our sample includes well studied sources which can be considered as templates of this early evolutionary stage of protostars. This selection of densely clustered, double and relatively well separated individual protostars consists the largest Herschel sample for which spectra will be taken in entire wavelength range. PACS detections of water, OH and OI lines will be used to determine the fundamental properties (such as density, temperature, infall rate, and molecular abundance and accretion rate) of the interacting components of a protostellar system: the infalling envelopes, disks and outflows. SPIRE data is expected to reveal lower state water lines and help to derive the gas temperature and density via the CO intermediat^el rotational lines. We aim to provide a valuable spectral reference database for better understanding and testing the theory of the earliest phases of star formation and we can examine the role of interaction between protostars in dense groups and multiple systems. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]