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 )
300
200
100
0
-100
-200
300
200
100
0
-100
-200
300
200
100
0
-100
-200
UGC01841 Central Slit: ∆v = 0 km s -1
-1.0 -0.5 0.0 0.5 1.0
Position along slit (arcsec)
-ve offset slit position
-1.0 -0.5 0.0 0.5 1.0
Position along slit (arcsec)
+ve offset slit position
-1.0 -0.5 0.0 0.5 1.0
Position along slit (arcsec)
Figure 4.28 The observed velocity profiles of UGC 1841 for each of the three observed
slit positions. The velocities are shown shaded according to the relative signal-tonoise
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.
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