Taxonomy of AGN circa 1980

1
Taxonomy of AGN - circa 1980
Seyfert 1 galaxy Seyfert 2 galaxy QSO Broad
Absorption Line (BAL) QSO Liner Quasar Fanaroff/R
iley FR1 and FR2 galaxy Broad line radio
galaxy Narrow line radio galaxy Flat Spectrum
Core Dominant Radio Source Steep Spectrum Lobe
Dominant Radio Source BL Lac object Optically
Violent Variable Quasar
Radio-quiet
Radio-loud
2
Two Basic Resources on Unification

• Antonucci, R.R.J. 1993, ARAA, 31, 473
  Unification models for AGN Quasars
• Urry Padovani 1995, PASP, 107, 803 Radio loud
  objects only

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Spectral Types of Emission-Line AGN
Type 2
Type 1
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Ancient History (Rowan-Robinson 1977)
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Early Evidence for Aspect-dependent Classification

• Alignment of optical polarization PA with radio
  structure in Type 1 objects (polarization
  typically lt1).
• Anti-alignment of optical polarization PA with
  radio structure in Type 2 objects (polarization
  1-5).
• General alignment of ionization cones with
  radio structure.

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Radio Structure vs. Optical Polarization(Antonucc
i 1983)
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The Hidden Seyfert 1 Nucleus in NGC
1068(Antonucci Miller 1985)
Polarized flux
7500 km/sec
Total flux
8 minutes of data in 1998 vs. 20 hrs in 1984!
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The Hidden Seyfert 1 Nucleus in NGC
1068(Antonucci Miller 1985)
Dusty, molecular torus
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A Slightly More Modern Picture
tv 0.01? R few kpc
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How the Torus Unifies AGN Classifications
Type 1
Type 1.5
Torus axis does not align with the axis of the
galaxy!
Type 1 in polarized light
NLR
BLR
Type 2
Dust grains
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Polarization at High Inclination (Type 2)

• Strong polarization
• Perpendicular to torus axis

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Polarization at Low Inclination (Type 1)

• Weak polarization
• Parallel to torus axis

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Clinching Evidence Direct imaging of Torus
(Ford et al. 1997)
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Clinching Evidence Images of Ionization
Cones(e.g., Zakamska et al. 2006)
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The LINER Galaxy NGC 4258
N
E
D 7 Mpc
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H20 Maser Emission from NGC 4258(Miyoshi, Cecil
et al. 1992-95)
N
E
From Keplerian velocities of masers, central
(black hole) mass is 3.6x107 M
v µ r -1/2 Keplerian velocity curves
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Polarized Emission Lines from NGC 4258(Wilkes et
al. 1995)
Dv 1000 km/s P.A. 86o
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Red and Polarized QSOs from 2MASS (Smith et al.
2000)
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A Type 2, Red QSO Comes out of the
Closet (Schmidt et al. 2002)
Dv 30,000 km/s!
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What is Wrong with these QSOs? (Smith et al.
2003)
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Red Type1 QSOs are Polarized!
Type 1 objects
(All show broad lines)
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Reddening/scattering by considerable dust, even
in polar directions
Hypothesis for Reddened, Polarized Type 1 QSOs
NLR
BLR
Dust grains
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Increased Scattering will Cause Reddest QSOs to
Appear as Type 1 Regardless of Orientation
Surplus of O III
Deficit of O III
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Unification of Radio-Quiet AGN
Seyfert 1 galaxy Seyfert 2 galaxy
Liner?
Type 1 QSO BAL QSO? Type 2 QSO
Face-on
Edge-on
Luminosity
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Unification of Radio-Loud AGN
BL Lac object Optically Violent Variable Quasar
Face-on
Broad line radio galaxy FR1, FR2, Narrow line
radio galaxy
Flat Spectrum Core Dominant Radio Source Steep
Spectrum Lobe Dominant Radio Source Quasar
Edge-on
Luminosity