Stellar Coronae:
Hot, Collisional X-Ray Sources
v
Physical environment:
•
Hot (
kT
~ 0.1 – 3 keV)
•
Density
(
n
~ 10
10
cm
-3
)
•
Optically thin
v
Ionization balance:
•
Standard electron-ion
collisional processes:
CI, RR, as well as EA
and DR
v
Line excitation:
•
Electron impact
8