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تسجيل مستخدم جديدBenchmarking PDR models against the Horsehead edge
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Jer^ome Pety
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To prepare for the unprecedented spatial and spectral resolution provided by ALMA and Herschel/HIFI, chemical models are being benchmarked against each other. It is obvious that chemical models also need well-constrained observations that can serve as references. Photo-dissociation regions (PDRs) are particularly well suited to serve as references because they make the link between diffuse and molecular clouds, thus enabling astronomers to probe a large variety of physical and chemical processes. At a distance of 400 pc (1 corresponding to 0.002 pc), the Horsehead PDR is very close to the prototypical kind of source (i.e. 1D, edge-on) needed to serve as a reference to models.
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After a discussion about the need for observational benchmark for chemical models, we explain 1) why the Horsehead western edge is well suited to serve as reference for models and 2) the steps we are taking toward this goal. We summarize abundances obtained to date and we show recent results.
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