Scientific Report


Workshop 170 on the excitation of the CO ladder was held in the Lorentz center from February 27 through March 2, 2012. A total of more than 50 participants attended the workshop from various countries.


Description and aims


The goal of this workshop was to bring together for the first time people from different galactic and extra-galactic key programs, and learn about their observations and favorite analysis tools (PDRs, XDRs, and shocks), and make a detailed inventory and comparison of the models. During the workshop we discussed the observations that were done by the various Herschel observations programs and how they do the interpretation with various available models. We also compared predictions of CO ladders resulting from preassigned theoretical test problems. Although in some case we reached good agreement between the codes, we also saw many discrepancies.




During the workshop we tried to understand the discrepancies, by comparing how different processes were implemented in each others codes. We agreed to implement key processes in a similar fashion. We will make follow up calculations, which will hopefully result in a paper, where we will highlight the conclusions of the workshop. We also had good discussions between modelers and observers. Observers learned more about using results from modeling, what can be trusted and what not. Modelers learned more about the needs of the observers.




It was a very fruitful workshop, where we had a good balance between presentations and discussion/splinter group meetings. The preassigned test problems made it possible to make a head start, without loosing time on too technical details, but focusing on the science right away.


We were very happy about the local organizational part of the meeting. There was ample opportunity of to have small meeetings, as well as central discussion. We thanks all the staff of the Lorentz center for making this workshop possible.



Edwin Bergin (U Michigan, United States)
Ewine van Dishoeck (Leiden Observatory, Netherlands)
Lars Kristensen (Leiden Observatory, Netherlands)
Edo Loenen (Leiden Observatory, Netherlands)
Rowin Meijerink (Kapteyn Astronomical Institute, Netherlands)
Volker Ossenkopf (U Köln, Germany)
Markus Röllig (U Köln, Germany)
Ruud Visser (U Michigan, United States)