Three narrow components of the Fe Ka line
6.4 keV
Fluorescent emission due to
cosmic-ray electrons hitting
cold (molecular) gas
Milky Way
6.7 + 6.9
keV
From faint X-ray binaries?
Interaction of non-thermal
electrons
with hot (0.2-0.5 keV) gas?
6.4 keV
Fluorescent emission due to
cosmic-ray electrons hitting
cold (molecular) gas
M81
6.7 + 6.9
keV
Interaction of non-thermal
electrons with hot
(0.2-0.5 keV) gas?
X-ray photoionised gas?
From faint X-ray binaries?