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The torus of gas and dust can block part of our view
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Seyfert 2 galaxies: Edge
on view
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Only gas well above
and below disk is visible
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See only “slow” gas narrow emission lines
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Seyfert 1 galaxies: Slightly
tilted view
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Hot high velocity gas
close to black hole is visible
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High velocities broad emission lines
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BL Lac objects: Pole on
view
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Looking right down
the jet at central region
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Extremely bright –
vary on time scales of hours
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Quasars: Very active AGN
at large distances
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Can barely make out
the galaxy surrounding them
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Were more common in
distant past
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