Gas Disks and Supermassive Black Holes in Nearby Radio Galaxies

NGC 7052: This elliptical galaxy has a nuclear dust disk. The STIS slits were
aligned parallel to the galaxy major axis, 1 ◦ from the dust disk axis. The weighted
mean observation - model residuals are plotted in Figure 4.16 and gives a minimum
at an offset of 280 km s −1 , equivalent to a galaxy recessional velocity of 4435 km s −1 .
The model velocity profiles for these observations are shown in Figure 4.39. Two
plots are shown as the velocity offset in this case was dominated by a large jump (∼
1000 km s −1 ) in the observed profile, the second plot shows an offset that best matches
the very central region. In the observed velocity profile a central velocity gradient
is observed which seems as if it may correspond to gas rotating in the potential
generated by a 1 × 10 8 M⊙ < M• < 9 × 10 8 M⊙ black hole. The nature of the second
velocity system is unknown, and generates far greater consequences for the velocity
than the potential nuclear black hole.
UGC 12064: This S0 galaxy has a nuclear dust disk. The STIS slits were aligned
parallel to the dust disk major axis. The weighted mean observation - model residuals
are plotted in Figure 4.17 and gives a minimum at an offset of −83 km s −1 , equivalent
to a galaxy recessional velocity of 5040 km s −1 . The model velocity profiles for these
observations are shown in Figure 4.40. It is not clear that the modeled velocity
profiles match any of the observed kinematics in the nuclear region, though they may
170