Gas Disks and Supermassive Black Holes in Nearby Radio Galaxies

(a)
(b) (i)
(ii)
(c)
(i) (ii) (iii) (iv)
(d)
(i) (ii)
(e)
(i) (ii) (iii) (iv)
Intensity (erg s −1 cm −2 Å −1 arcsec −2 )
v r (km s −1 )
8•10 −15
6•10 −15
4•10 −15
2•10 −15
4700
4600
4500
4400
4300
4200
4100
0
Reduced 2−D Spectrum
Single Gaussian per Line Fit
v r
X = −0.2
Y (arcsec)
Hα+[NII] & [SII] − Narrow Line Fit
0.91
0.41
−0.10
−0.61
σ gas
v r
+0.2 0.0 −0.2
X (arcsec)
−2•10
6584 6638 6691 6745 6799 6852 6906
Wavelength (Angstroms)
−15
X = 0.0
X = +0.2
−1.01 −0.34 0.34 1.01
Y (arcsec)
σ gas (km s −1 )
500
400
300
200
100
0
X = −0.2
X = 0.0
X = +0.2
−1.01 −0.34 0.34 1.01
Y (arcsec)
Intensity (erg s −1 cm −2 Å −1 arcsec −2 )
F (10 −14 ergs s −1 cm −2 Hz −1 )
8•10 −15
6•10 −15
4•10 −15
2•10 −15
0.5
0.4
0.3
0.2
0.1
0.0
10
8
6
4
2
0
0.4
0.3
0.2
0.1
0
σ gas
+0.2 0.0 −0.2
X (arcsec)
[NII] 6585 Flux
X = −0.2
X = 0.0
X = +0.2
0.0
−0.1
−1.01 −0.34 0.34 1.01
Y (arcsec)
F([NII] 6585)
+0.2 0.0 −0.2
X (arcsec)
Hα+[NII] & [SII] − Narrow & Broad Cpt. Fit
[NII] 6585/Hα
10.0
1.0
0.1
F([NII])/F(Hα)
+0.2 0.0 −0.2
X (arcsec)
−2•10
6584 6638 6691 6745 6799 6852 6906
Wavelength (Angstroms)
−15
[NII]/Hα
X = −0.2
X = 0.0
X = +0.2
−1.01 −0.34 0.34 1.01
Y (arcsec)
Figure 3.1 Key to plots. Region (a): the HST acquisition image for each galaxy
observed is shown with the positions of the observed long slits overlaid. The relative
position angles of the galaxy major axes measured from the central isophotes (dashed
lines) and the arcsecond scale radio jets (dotted lines) are shown. These lines cross,
and a North-East indicator is drawn, at the location of the central pixel (see text).
Region (b): (i) the central portion of the reduced 2-D spectrum from the central
slit position is shown along with (ii) an image created from fitting a set of 5 Gaussian
lines to the same. Region (c): plots representing the two-dimensional distributions
of parameters measured by fitting a one Gaussian per emission line model to spectra
from the nuclear region. The dashed and dash-dot lines indicate the directions of the
minor and major axes respectively. The lines cross at the location of the central pixel.
We show: (i) radial velocity (filled circles represent velocities greater than the mean,
empty circles represent velocities less than the mean and the radius of each point [i,j]
is proportional to |vi,j − vmean|); (ii) velocity dispersion (the radius of the circle is
proportional to σi,j); (iii) integrated line flux (the area of each point is proportional
to Fi,j); and (iv) [N II]6585 / Hα ratio (The radius of each circle is proportional to
log(F([N II]6585)/F(Hα))). Region (d): single Gaussian per line fit and residuals
without (i) and with (ii) the additional free component described in the text for the
central spectrum of each galaxy. Region (e): plots of (i) radial velocity, (ii) velocity
dispersion, (iii) [N II] line flux and (iv) [N II]6585 / Hα ratio along each slit measured
by fitting a one Gaussian per line model to the emission line spectra. The vertical
dotted line indicates the Y position of the central row. The dash-dot line in the
velocity panel indicates the quoted recession velocity for the galaxy (see Table 2.1).
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