Astrophysics (index)about

photodissociation region

(PDR, photon-dominated region)
(cloud of partially-ionized atomic hydrogen)

A photodissociation region (or photon-dominated region or PDR) is a region where photodissociation of molecular hydrogen is taking place, producing neutral atomic hydrogen, along a front where ultraviolet EMR from a nearby source is sufficiently intense to warm the molecules to the point where the balance favors atomic hydrogen. A common location is at the border between a HII region and a molecular cloud.


(hydrogen,cloud type,star formation,gas,ionization)
http://en.wikipedia.org/wiki/Photodissociation_region

Referenced by:
cloud
HII region (HII)
photodissociation

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