Gas Disks and Supermassive Black Holes in Nearby Radio Galaxies

Gas Radial Velocity (km s -1 )
Gas Radial Velocity (km s -1 )
Gas Radial Velocity (km s -1 )
400
200
0
-200
-400
-600
-800
400
200
0
-200
-400
-600
-800
400
200
0
-200
-400
-600
-800
NGC7052 Central Slit: ∆v = 280 km s -1
-0.4 -0.2 0.0 0.2 0.4
Position along slit (arcsec)
-ve offset slit position
-0.4 -0.2 0.0 0.2 0.4
Position along slit (arcsec)
+ve offset slit position
-0.4 -0.2 0.0 0.2 0.4
Position along slit (arcsec)
Gas Radial Velocity (km s -1 )
Gas Radial Velocity (km s -1 )
200
0
-200
-400
-600
-800
-1000
200
0
-200
-400
-600
-800
-1000
NGC7052 Central Slit: ∆v = 550 km s -1
-0.4 -0.2 0.0 0.2 0.4 0.6
Position along slit (arcsec)
-ve offset slit position
-0.4 -0.2 0.0 0.2 0.4 0.6
Position along slit (arcsec)
+ve offset slit position
-0.4 -0.2 0.0 0.2 0.4 0.6
Position along slit (arcsec)
Figure 4.39 The observed velocity profiles of NGC 7052 for each of the three observed
slit positions: (left) offset by the velocity and slope calculated in §4.2.5 and (right)
with a velocity offset of 550 km s −1 , and the velocity field running from negative
to positive, which provides a more meaningful fit to the nuclear region (judged by
the author), the velocity fit in §4.2.5 was strongly influenced by the large velocity
feature at ∼ 0. ′′ 15 from the nucleus. The velocities are shown shaded according to the
relative signal-to-noise of each spectrum, formal errors from the fit are also indicated
(see Chapter 3). The three solid lines show model velocity profiles for no black hole,
a 1 × 10 8 M⊙ black hole and a 9 × 10 8 M⊙ (the steeper lines from models with the
greatest black hole mass). See text for details of the models. The dashed vertical lines
give a rough approximation of the radius of influence of a black hole based on the
mass estimate from the M• −σ relation and the size of the random motions observed.
Gas Radial Velocity (km s -1 )
200
0
-200
-400
-600
-800
-1000
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