Physical conditions and chemical evolution of the gas towards the Orion Bar photodissociation region using Herschel/PACS and SPIRE spectro-imaging observations
Abstract
Due to its proximity and edge on orientation, the Orion Bar is a luminous prototypical PDR. We will present new spectral-imaging of the Orion Bar obtained with the Herschel/PACS and SPIRE instruments, as part of the Evolution of interstellar dust Key Project of the SPIRE consortium. These fully sampled maps cover the entire region from the illuminating star to/and across the Bar. Such spatial coverage coupled with the angular resolution of Herschel enable us to trace the synergy between the physical conditions and chemical evolution of the gas across the illuminated interfaces in the PDRs. In particular, we make use of the main cooling lines ([CII], [OI], [NII], [CI], CO) to derive the local conditions of the gas and to provide fully sampled maps with the distribution of important molecular species (e.g. CH+, CO, H2O, H2S). The observed atomic and molecular spatial distribution and variation in the line fluxes will be discussed in relation to the underlaying complex geometry and linked to the energetics associated with the Trapezium stars.
- Publication:
-
The Molecular Universe
- Pub Date:
- May 2011
- Bibcode:
- 2011IAUS..280P.189H