CORDIS - EU research results

Dynamical Photo-dissociation Regions: Observations and Modelling

Final Activity Report Summary - DYNPDRS (Dynamical photodissociation regions: observations and modelling)

The project has progressed in the 3 anticipated directions:

1) Construction of an improved computational model simulating the thermodynamics, the chemistry and the radiation transport in ''Photodissociation Regions'' (PDRs* ).
* ''PDRs'' are Interstellar clouds or Circumstellar disks illuminated by a strong UV field (e.g a nearby star).
Most important results:
- Development of a new method to solve the UV-radiative transfer equation, the equation that describes the propagation of UV radiation through interstellar clouds or circumstellar disks, in the presence of gas and dust. The new methodology has been implemented in the ''Meudon PDR code'', a public computational model used by several research groups and applied to the physics and photochemistry of ISM clouds, disks and galaxies.

2) Multi-telescope observational study of several PDRs of the Interstellar Medium (ISM):
- Preparation, participation and interpretation of PDR observations using the IRAM-30m (Spain) and CSO (Hawaii) radiotelescopes, the Plateau de Bure Interferometer (France) and the Spitzer Space Telescope.
Most important results:
- Mapping the ''Horsehead Nebula'' in different key molecular diagnostics of the prevailing physics and chemistry (goal: better understanding of the carbon, sulfur and deuterium chemistry in UV-illuminated gas).
- Detection of a new young protostar and associated outflow near ''Cederblad 201 Nebula''. (goal: understanding how sunlike stars form in thepresence of significant ambient UV radiation fields)

3) Scientific preparation of the next generation of far-IR space missions (Herschel and SPICA):
- Scientifc exploitation of the Infrared Space Observatory data base.
- Preparation and submission of Guaranteed- and Open-Time Key Project proposals for the esa's Herschel Space Telescope (to be launched in 2008).
- Submission of the ''SPICA'' proposal to the esa's Cosmic Vision 2015-2025 call. Participation in the ''European Instrument for SPICA'' (ESI) preliminary studies, as member of the ESI science team.
Most important results:
- Publication of the Far-IR (app. 43-197 um) spectral surveys of Orion and Sgr B2 star forming regions. These are the only 2 full line surveys taken by the Infrared Space Observatory at high spectral resolution and can be considered the ''Rosetta Stone'' spectra of the far-IR domain.
- Participation in the scientific preparation of several Herschel Guaranteed-Time Key Programmes as ''Associated Member'':
*The Orion and Sgr B2 Star-Forming regions* (PI: Ted Bergin, University of Michigan).
*The warm and dense ISM* (PI: Volker Ossenkopf, University of Cologne, Germany).
*Molecular carriers in the ISM* (PI: Maryvonne Gerin, Observatoire de Paris, France).
*Water in Star-Forming Regions* (PI: Ewine van Dishoeck, University of Leiden)
and several Herschel Open-Time Key Programmes, e.g.,:
''Mapping Sgr B2 and Orion Star-Forming Regions'' (Project Coordinator)
- Note that he far-IR space mission project SPICA has been finally selected in the esa's Cosmic Vision 2015-2025 call.