Small
fraction of galaxies have extremely
bright
unresolved star-like nuclei
Very
large energy generation
Brightness
often varies quickly
Implies
small size (changes not smeared out by light-travel time)
High
velocities often seen (> 10,000 km/s in lines)
Emission
all over the electro-magnetic spectrum
Jets seen emerging from galaxies
Already
talked about jets last week. Next two
slides are review.
Think
about the implications of jets.
Timescales, angular momentum. What do they
imply?