•Seyfert galaxies
–like normal spirals but with
bright (> 1011L¤),
point-like (rapid variability) nuclei; dusty - 75% radiation in
infrared, internal Doppler motions 1000 - 3000 km /s
•
•Radio galaxies (10%)
–often appear like
elliptical galaxies; BUT strong radio emission (lobes) outside
galactic nucleus, extend 50 - 1000 kpc ! ® result from very energetic processes
in nucleus
e.g. Centaurus A: visible ® seems like E2, 500 kpc
diameter
•
•All active galaxies
–vast amounts of energy emitted from or generated in central compact
nucleus - jets common (indicate bursts of activity), probable
origin? – galaxy-galaxy interactions
•