Gas Disks and Supermassive Black Holes in Nearby Radio Galaxies

intensity contours are aligned concentric ellipses with an axial ratio
153
q ′ ≡ cos 2 i + q 2 sin 2 i. (4.5)
Values of q ′ , measured from the ellipticity of the isophotes in the WFPC2 images,
are also listed in Table 4.1. Though the values of q ′ , and of the position angle of the
major axis of the isophotes varies over the region in which we are interested (Verdoes
Kleijn et al., 1999), we do not expect this to have a significant impact on the results
we derive (see Verdoes Kleijn et al., 2002b, and Section 4.2.6 below).
We determined the mean stellar flux profiles in the direction along the semi-
minor axis with least dust obscuration, in the reddest image observed by WFPC2
(to minimize the effects of both dust and emission lines) for each galaxy. We then
iteratively fit the model parameters to obtain the best fitting values for the parameters
α, β, a and j0, these are shown in Table 4.3.
We assume that the stellar mass density ρ(R, z) follows the luminosity density
distribution j(R, z) through a constant mass to light ratio (Υ) towards the center of
the galaxy. No conclusive data exist about how Υ may change towards the center,
though we observe changes in (V −I) (Verdoes Kleijn et al., 1999), much of this may
be attributed to dust rather than to changes in the stellar population. The fit is not
incredibly sensitive to this parameter until some distance from the nucleus where the