We present in this section images of the dust lane galaxies in the radio sample along with various parameters related to the dust lanes. The parameters we provide include the angle of (mis)alignment between the dust lane and the major axis of the galaxy and between the dust lane and the radio axis. The latter is sometimes ambiguous owing to the poor quality of the radio maps.
We estimate the color excess in the dust lane by comparing the color
in it with that of the surroundings. For this purpose we used a
square aperture with side
(3 pixels) on the
images separately to extract magnitudes along the lane and in a
neighboring region free of dust. The mean of the color excesses,
E(B-R), obtained in this
manner is then used for further calculations. We use the standard
relation from Savage and Mathis (1979) to calculate the optical
depths in
:
Here,
denotes wavelength and
and
respectively denote the extinction and optical depth at
.
We have assumed here that the dust lane obscures all stars.
Following Burstein and Heiles (1978), the column density of neutral hydrogen and the total neutral hydrogen content in the dust disk can be obtained from
where, D is the distance to the galaxy.
We assume that the dust-to-gas ratio in these galaxies is similar
to the ratio in our Galaxy,
, to obtain the dust mass.
This is a lower limit, since not all stars
are actually obscured and the actual amount is at least 1/f
larger where f;SPMlt;1 is the fraction of stars obscured.
We describe below dust related features found in the dust lane galaxies.
[Properties of the radio galaxies with dust lanes]
Properties of the dust lane radio galaxies from our sample.
The dust mass is calculated as described in Section
.
The dust lanes are, in general, not perpendicular to the radio axis.
| Object | z | size | E(B-R) | | | | | |
| | magnitude | | max | | | |||
| 0354-263 | 0.30+ | | 0.20 | 0.42 | | -0.010 | 45 | 45 |
| 0420-263 | 0.130 | | 0.15 | 0.32 | | -0.010 | NA | 10 |
| 1254-268 | 0.135 | | 0.10 | 0.21 | | -0.003 | 30 | 30 |
| 1257-253 | 0.045 | | 0.10 | 0.21 | | -0.005 | 30 | 60 |
| 1323-271 | 0.044 | | 0.10 | 0.21 | | -0.003 | 30 | 00 |
| 1344-241 | 0.019 | | 0.07 | 0.21 | | -0.005 | 00 | 00 |