| Description |
We propose to use the unique power ot Herschel to analyze the mostextreme resolvable photdissociation regions, i.e. those at low metallicity and energized by hard radiation. With a modest investment of observing time, we will probe a unique part of parameter space, providing a strong lever arm to test the validity of PDR models. Furthermore, the conditionsof low metallicity and hard field are exactly those which are moreprevalent in the early universe compared to today, and increasingly important to understand the interstellar medium of early galaxies.The regions we propose to study in detail in the local universe are a unique window into how the first stars affected their environments, which we will not easily study at this resolution.The only PDRs close enough to resolve their structure and at lowmetallicity are in the Magellanic Clouds. There are only a few nebulaein the Clouds that are clearly energized by the extremely hardradiation from Wolf-Rayet Stars, and we will analyze two in eachgalaxy, which combined with our existing Spitzer and Herschel data willprovide unprecedented information on PDR physics throughout the universe. |
