Astrophysics (Index)About

photodissociation region

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

A photodissociation region (or photon-dominated region or PDR or photodissociation front) 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)
Further reading:

Referenced by pages:
HII region (HII)