The Excited and Exciting ISM in Galaxies: PDRs, XDRs ... - Caltech

500 pc
Model feedback zone
Mrk 231 3 main components:
150 pc
PDR 1:
n=10 3.5 , G 0 =10 2 , r~500pc
Large scale molecular gas
à Low-J CO lines
PDR 2:
n=10 5 , G 0 =10 3.5
Small, dense SF clumps
à mid-J CO lines
XDR:
n=10 4.2 , F X =28 cgs, r~150pc
Circum-nuclear disk
à High-J CO, OH + , H2O +