Herschel PACS and SPIRE investigation of water fountains

Water fountains (WFs) are late AGB and postAGB objects that show the earliest known manifestation of collimated massloss in evolved stars, with jets that have dynamical ages of only 5100 yr and sizes as small as 100500 AU. These fast collimated outflows, impinging onto the circumstellar material at the end of the AGB phase, are presumably responsible for the shaping of asymmetric planetary nebulae (PN), with the highly asymmetric H2Omaseremitting PNe being presumably the immediate descendants of WFs. Therefore, WFs and H2OPNe are key objects to study the shaping of PNe. Since their thick envelopes make them strongly obscured in the optical and nearIR, their inner circumstellar structure would be best traced at longer wavelengths. Here we propose the acquisition of Herschel PACS and SPIRE deep imaging photometric observations of all known WFs and H2OPNe to be added to nearIR, midIR, submm, and mm data to continue building the spectral energy distribution (SED) of these sources, and to check for the presence of extended material. The characterization and theoretical modeling of their SEDs will be used to infer the presence of disks and to estimate the physical parameters of circumstellar disks and envelopes, which in their turn will impose constraints on the models for the generation of jets in evolved objects. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]