Heating the Gas in Photodissociation Fronts
نویسنده
چکیده
ISO has provided us with a new perspective on gas temperatures in photodissociation regions through measurements of line emission from rotationallyexcited levels of H2. The H2 rotational level populations provide a thermal probe, showing that gas temperatures Tgas ≈ 500 − 1000K prevail in a portion of the PDR where significant H2 is present. Such high gas temperatures were unexpected. Theoretical models for the S140 PDR are presented. Possible mechanisms for heating the gas to such high temperatures are discussed.
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تاریخ انتشار 1999