Appendix A: Results for individual objects

0255 + 058: The optical counterpart of 3C 75, the central radio source of the cluster Abell 400, is an interesting case of a dumbbell galaxy, with components separated by $\sim20\hbox{$^{\prime\prime}$ }$ and with a radial velocity difference of 500 km s^-1. Twin radio jets depart from each of the two optical nuclei (Owen et al. 1985), making this radio source extremely unusual. The large scale radio structure is classified as FRI (Morganti et al. 1993).

Unfortunately, a bright satellite crossed the field, passing close to the central part of the dumbbell system (see Fig. 1). Nevertheless, using the AIAP masking facility, we were able to obtain a photometric deblending, by iterative modeling of the two components. In spite of the appearance, the geometry of the two galaxies looks rather regular, apart from a slight off-centering of the outermost isophotes. Luminosity and geometrical profiles suggest both components are ellipticals. In particular, the luminosity profile (see Fig. 12) of the northern galaxy is consistent with the presence of a nuclear point source.

0257 - 398: The optical counterpart of this radio source is a rather isolated galaxy at $z\simeq 0.066$ (Scarpa et al. 1996). The geometrical profiles of this object are highly suggestive of an S0 morphology (increasing ellipticity, positive c4 coefficient).

0307 - 305: This object seems to be a rather isolated galaxy. Its luminosity and geometrical profiles suggest a regular elliptical morphology, with a possible nuclear point source.

0312 - 343: The source looks like a large elliptical with regular morphology. The luminosity profile strongly suggests the presence of a bright nuclear point source.

0325 + 023: The radio morphology of 3C 88 is dominated by two symmetric and well developed lobes at PA = $60^\circ$, and is classified as FRII (Morganti et al. 1993). The optical counterpart which coincides with the radio nucleus, is an elliptical galaxy, whose major axis has position angle PA = $-30^\circ$. This is remarkably well defined and stable (Fig. 12) and, within the uncertainty, orthogonal to the radio structure.

0332 - 391: A radio map of this FRI radio source is reported by Jones & McAdam (1992). Figure 1 shows that the host galaxy is embedded in a quite dense environment. In particular, it seems to interact with another (very similar) galaxy, whose angular separation from the radio galaxy is $\sim 76^{\prime\prime}$. The luminosity profile is consistent with the presence of a nuclear point source.

0344 - 345: As for the previous case, the galaxy hosting this radio source turns out to be embedded in a rich environment and seems to interact with a close elliptical companion. The luminosity profile is consistent with the presence of a nuclear point source, whereas the geometrical profiles suggest regular elliptical morphology. This source is also interesting for having strong optical emission lines (Scarpa et al. 1996), and complex radio morphology (Jones & McAdam 1992).

0427 - 539: The optical counterpart of this radio source is a spectacular case of dumbbell morphology in rich environment, with nuclei separated by $\sim 30^{\prime\prime}$ ($\sim$ 33 kpc). The radio source is associated with the South-East component of the dumbbell system. After deblending the two galaxies, we observe a regular elliptical morphology for the brightest object, whereas the other galaxy shows a rather amorphous and broad light distribution (see contours in Fig. 10).

0430 + 052: 3C 120 is a well studied radio source, displaying superluminal motion (Zensus 1989). The spectrum of the optical counterpart is quasar like (Tadhunter et al. 1993), and the galaxy has been often classified as Seyfert 1, even if its spiral morphology has never been clearly established.

0434 - 225: The galaxy hosting this radio source is embedded in a moderately rich environment. It has regular elliptical morphology, as illustrated by the luminosity and geometrical profiles, as well as by its isophotal contours. The luminosity profile is consistent with the presence of a nuclear point source.

0446 - 206: The optical counterpart of this radio source lies in the very dense environment of the cluster Abell 514. The host galaxy is a normal elliptical.

0452 - 190: An interesting case of dumbbell galaxy. The radio source coincides with the Southernmost component. After deblending, both galaxies show very regular morphology (see Fig. 10), suggesting the dumbbell appearance may just be due to chance projection. Based on the shape of their radial profile we conclude the northernmost galaxy is an S0, and the other one an elliptical.

0453 - 206: In the optical band NGC 1692 looks like a large, undisturbed elliptical galaxy, in spite of the presence of two nearby galaxies both at a projected distance of $\sim 66\hbox{$.\!\!^{\prime\prime}$ }5$ from the radio galaxy. The south-east companion is likely to be an edge-on spiral showing a pronounced C-shape.

0511 - 305: Even if the optical counterpart of this radio source is located in a rather poor environment, the host galaxy appears morphologically disturbed by the presence of some small companions. In particular, two small compact galaxies on opposite sides with respect to the galaxy center are aligned with an elongated structure extending for $\sim 30^{\prime\prime}$ westward.

0533 - 377: The optical counterpart of this radio source is an elliptical galaxy, located at the end of a chain of small galaxies. The surrounding environment is very dense, with several galaxies superposed on the main object.

0546 - 329: The host galaxy of this radio source is a large, normal elliptical. The only noticeable thing being the presence of a nearby galaxy pair.

0548 - 317: A rather normal elliptical galaxy in a rich environment, with several small galaxies projecting on its halo. The luminosity profile suggests the existence of a nuclear point source.

0620 - 526: This FRI radio source (Jones & McAdam 1992) shows weak emission lines superposed onto the continuum spectrum of a typical early-type galaxy (Simpson et al. 1996). The source was also detected in the X-ray band (Gioia & Luppino 1994). Unfortunately, our image of the galaxy is disturbed by the presence of several saturated columns of the CCD, due to a nearby bright star. Nevertheless, using appropriate masking we were able to produce a reliable radial profile, from which we infer the existence of a nuclear point source.

0625 - 354: The optical counterpart of this FRI radio source, located at the center of the cluster Abell 3392, is a giant elliptical embedded in a rich environment. It is worth noticing the presence of a strong point source in the nucleus of this galaxy, also supported by the emission lines observed in its optical spectrum (Tadhunter et al. 1993).

0625 - 536: The optical counterpart of this radio source is the South-East member of a dumbbell system, located in the cluster Abell 3391. After deblending the two galaxies with the iterative two-galaxy fitting procedure (Fig. 10), we found both galaxies show strong displacement of the isophotal centers roughly perpendicular to their alignment, as expected in strong interactions.

0634 - 205: The host galaxy is a normal elliptical lying in a rather poor environment. Strong emission lines have been observed in its optical spectrum (Simpson et al. 1996). The image of the galaxy is disturbed by the light from a satellite which passed close to the center of the source. This structure was masked during isophotal analysis.

0712 - 349: The galaxy hosting this radio source is a normal elliptical with regular morphology in a poor environment.

0718 - 340: The optical counterpart looks like a normal elliptical with regular morphology in a poor environment.

0806 - 103: 3C 195 is an FRII radio source (Morganti et al. 1993), with the optical counterpart exhibiting emission lines in its optical spectrum (di Serego Alighieri et al. 1994). The host galaxy is located nearby a very bright star which makes it difficult to derive luminosity andgeometrical profiles extended to the outer regions. The brighter part of the galaxy, which can be reliably studied, suggests this galaxy has complex structure and a nuclear point source. The environment is relatively rich and at least two small galaxies may be gravitationally interacting with the radio galaxy.

0915 - 118: The optical counterpart of the FRI radio source 3C 218 (Morganti et al. 1993), is an early-type galaxy most likely a member of a small group. Ionization emission lines were detected in its optical spectrum (Simpson et al. 1996).

0940 - 304: The optical spectrum of this radio source is of an early-type galaxy with old stellar population (Scarpa et al. 1996). The optical morphology confirms this classification. The environment is poor.

0945 + 076: The radio morphology of 3C 227 is very elongated East-West with terminal hot spots, and is classified as FRII (Morganti et al. 1993). The optical counterpart resides in a poor environment, and apart from the slight tendency to have disky isophotes, the most important optical feature is the presence of a very bright nuclear source. This is consistent with the detection of strong emission lines with broad wings in the optical spectrum (Simpson et al. 1996). The major axis of the galaxy, at almost constant position angle PA $\sim 0^\circ$, is perpendicular to the radio structure.

1002 - 320: The optical counterpart is an elliptical galaxy, most likely interacting with a nearby companion at projected distance $\sim 56''$.

1043 - 290: Its optical spectrum is characteristic of an elliptical galaxy (Scarpa et al. 1996). The surface photometry of this galaxy is perturbed by the influence of a bright nearby star. Its morphology is clearly of elliptical type and its luminosity profile is reliable enough to indicate the presence of an outer halo. The environment looks relatively rich.

1053 - 282: This object lies in rich environment and is surrounded by several small galaxies, some of which are likely to be in interaction with the radio source. The surface photometry is made difficult both because of the above mentioned companions and also due to the presence of a relatively bright star projecting onto the galaxy body. Both morphology and luminosity profile are consistent with the presence of a extended disk.

1056 - 360: The radio structure of this source is large and complex (Jones & McAdam 1992). The optical counterpart lies in a rich environment and coincides with a close galaxy pair similar to 0452-190. The radio galaxy is the brightest of the two and has normal luminosity and geometrical profiles for an elliptical galaxy. The optical spectrum exhibits emission lines (Simpson et al. 1996).

1107 - 372: NGC 3557 is an FRI radio source (Birkinshaw & Davies 1985) in which H$\alpha$+[NII] extended emission has been detected (Goudfrooij et al. 1994). The luminosity and geometrical profiles indicate a regular elliptical morphology.

1123 - 351: Its optical counterpart is a large elliptical galaxy with undisturbed morphology.

1251 - 122: 3C 278 is an FRI radio source (Morganti et al. 1993). The optical counterpart is the Southernmost component of a dumbbell system. After deblending the image of the two galaxies, we found both components are heavily disturbed by tidal interaction.

1251 - 289: The host galaxy inhabits a relatively poor environment and shows undisturbed elliptical morphology in its outer part. On the contrary, the inner region appears irregular and elongated suggesting the presence of either a nuclear dust lane or a double nucleus. 1257 - 253: An elliptical galaxy with undisturbed morphology, surrounded by several nearby companions. The optical spectrum is typical of early type galaxies without emission lines (Scarpa et al. 1996).

1258 - 321: This radio galaxy lies in the cluster Abell 3537. After masking the light from two nearby bright stars, the surface photometry indicates a regular elliptical morphology and a nuclear point source.

1318 - 434: NGC 5090 hosts an FRI radio source (Morganti et al. 1993) studied in detail by Lloyd et al. (1996). The galaxy looks like a normal giant elliptical, over which projects NGC 5091, an edge-on spiral.

1323 - 271: The host galaxy lies in cluster Abell 1736 and looks like a normal elliptical in interaction with a small S0 galaxy.

1333 - 337: A regular elliptical galaxy located at the center of cluster Abell 3565. Optical emission lines were detected within few arcsec of the nucleus (Goudfrooij et al. 1994).

1344 - 241: The host galaxy lies in a rather poor environment. Isophotal contours and geometrical profiles (increasing ellipticity, constant position angle and positive c4 coefficient) suggest it is an S0 galaxy. However, signatures of a disc are not seen in the luminosity profile.

1354 - 251: This radio galaxy inhabits a relatively poor environment. Its optical morphology is of an undisturbed elliptical galaxy, as confirmed also by the optical spectrum (Scarpa et al. 1996).

1400 - 337: The optical counterpart is a large, regular elliptical with a bright nucleus, located at the center of the cluster Abell 753.

1404 - 267: A large and undisturbed elliptical galaxy lying at the center of the Abell cluster 3581. Since no radio maps are available for this radio source, we guess its FRI radio morphology from the power-morphology relationship.

1637 - 771: The radio source is estimated by Morganti et al. (1993) to have an FRII radio morphology. Optical spectra have revealed the presence of relatively strong emission lines (Tadhunter et al. 1993; Simpson et al. 1996). The luminosity profile of the host galaxy is consistent with the presence of a nuclear point source. The environment is rather poor.

1717 - 009: According to Morganti et al. (1993), 3C 353 is an FRII radio source. Emission lines have been detected in its optical spectrum (Tadhunter et al. 1993), and a LINER type spectrum has been also observed (Simpson et al. 1996). In our image the galaxy appears undisturbed in the outer regions, while in the center both luminosity and geometrical profiles support the existence of a bright point source.

1733 - 565: An FRII radio source (Morganti et al. 1993), with emission lines in the optical spectrum (Simpson et al. 1996). The optical counterpart is most probably an elliptical as suggested by its radial profile which precisely follows a de Vaucouleurs law. A nuclear point source is also observed.

1928 - 340: The host galaxy looks like a normal elliptical located in a small galaxy group.

1949 + 023: 3C 403 is an FRII radio source (Morganti et al. 1993) located in a poor environment. Strong emission lines were observed in its optical spectrum (Simpson et al. 1996; Tadhunter et al. 1993). In spite of the presence of a nearby bright star we derive for this galaxy a reliable profile, which clearly indicates a normal elliptical structure.

2221 - 023: 3C 445 is a well known radio source, and broad emission lines have been observed in its optical spectrum (Eracleous & Halpern 1994; Corbett et al. 1998). The optical morphology is characterized by the presence of an extremely bright nuclear point source.