Online Material

Appendix A: The sample of newly discovered GRGs and their properties

Here, we present notes on the radio structure, the host galaxies and the optical spectra of the sources. Table .3 presents the flux densities and positions of the radio cores and the host galaxies. Table .4 lists several other radio properties and the redshifts of the sources. Further, we present a table with the log of the INT observations (Table .2) and a table with the wavelengths and redshifts of spectral emission and absorption features we have measured in the spectra of the sources (Table .5). Finally, we present the radio and optical images of the sources, and the optical spectra of their host galaxies. Radio contour plots mostly are from the WENSS and/or the NVSS surveys. The FWHM beam size is indicated in a separate panel, usually situated in the lower left corner of the contour plot. The flux density level of the first contour can be found in Table .6. Unless indicated otherwise in this table, contour levels have been plotted at (-1,1,2,4,8,16,32,64,128,256) times the flux density level of the first contour. For the 1.4-GHz WSRT observations, Table .6 also gives the major and minor axes (FWHM) of the restoring beam. Also, we present overlays of our highest resolution radio map with the optical fields, usually retrieved from the digitized POSS-I survey, or POSS-II whenever available (see Table .6). The range of grey scales is such that the contents of the optical field is shown best. In case the identification of the host galaxy of the radio source is not apparent from the optical image, we have encircled it or used an arrow to point it out. The optical spectra of the host galaxies have the identified emission and absorption features indicated. In the plots of the spectra, the "$\oplus$''-symbol indicates the presence of an atmospheric feature, such as an imperfectly subtracted bright sky-line or an atmospheric absorption band. The " $\downarrow$''-symbol indicates the presence of a feature resulting from a cosmic ray impact that could not be properly removed from the data.

B0211+326: This ${\sim}5\hbox{$^\prime$ }$-large radio source has been shortly observed with the WSRT, but no radio core has been detected. On the POSS-II image we find a small group of faint galaxies situated halfway between the two radio lobes. The brightest of these is most likely the host galaxy, since its optical spectrum shows bright emission lines. We find a redshift of 0.2605, so that the projected linear size of the radio source is 1.6 Mpc.

B0217+367: An overlay of a 1.4-GHz WSRT radio map with the optical field shows that a ${\sim}10$ mag galaxy coincides with a central compact radio structure. A higher resolution 2.7-GHz map presented by Faulkner (1985) shows a radio core with two jets. The western jet is bend and has a bright knot at a distance of $20\hbox{$^{\prime\prime}$ }$from the core. Only the western radio lobe is connected to this radio core by a faint bridge. The lobe itself shows several twists and a diffuse outer structure which is only barely detected in the NVSS. The optical spectrum of the host galaxy shows weak [N II]6584 and [S II]6717/6731 emission lines. The redshift of the host galaxy is 0.0368, yielding a projected linear size of 0.95 Mpc.

B0648+733: The compact radio source located between the two radio lobes coincides with a galaxy on the POSS-I plates. A more sensitive VLA observation shows that the western lobe has an edge-brightened radio structure (Lara et al. 2001); our WSRT map only shows the bright hotspot. The optical spectrum of the identification shows strong emission lines. The redshift is 0.1145, yielding a projected linear size of 2.0 Mpc. The compact source overlapping with the eastern radio lobe on the NVSS radio map is most likely an unrelated background source.

B0648+431: This ${\sim}10\hbox{$^\prime$ }$-large radio source consists of four main components. An overlay of the 1.4-GHz WSRT radio map with an optical image shows that the eastern of the two middle component coincides with a 12 mag optical galaxy. An optical spectrum of the galaxy shows weak [N II]6548,6583 line-emission on top of a stellar continuum, at a redshift of 0.0891. The projected linear size of the radio source is 1.3 Mpc.

B0658+490: In the WENSS radio map this source is an ${\sim}19\hbox{$^\prime$ }$-large complicated radio structure with a fairly diffuse eastern part, three compact sources in the middle and a diffuse western extension. The FIRST survey has resolved the central source, and shows that it has a jet-like extension in the direction of a larger jet-like feature on the NVSS radio map. The central source coincides with an 11 mag. Optical galaxy, whose optical spectrum shows weak [NII]6548/6583 emission. The redshift is 0.0650. The two bright compact sources west of the radio core are resolved in the FIRST survey. The westernmost one appears to be an edge-brightened radio lobe, the other is more compact and has a radio tail pointing away from the radio core. It is unclear if this component is truly associated with the large radio source. If it were an unrelated source, the lack of an optical identification on the POSS-II survey suggests that it is at a much higher redshift than the host galaxy of the central radio source. Assuming that all radio structures are part of a single radio source, it has a linear size of 1.9 Mpc.

B0747+426: This is a $6\hbox{$^\prime$ }$-large radio source with a bent radio structure. The southern lobe is larger and more diffuse. Neither of the two lobes contains a bright hotspot. Near the central bent a 17 mag galaxy is detected which coincides with a weak, unresolved source in the FIRST survey, presumably the radio core. Its optical spectrum reveals [O II]3727 emission and a stellar continuum. The redshift is 0.2030, yielding a projected linear size of 1.5 Mpc.

B0750+434: Although only a weak radio source in the WENSS, this object is one of the largest radio sources we have discovered in this project. The central source, unresolved by FIRST, coincides with a 16.7 mag star-like object. An optical spectrum reveals strong emission lines, among which broad Hydrogen Balmer lines, and a blue-colored continuum. The redshift is 0.3474, which is the highest of all sources presented here. The southern radio lobe is resolved by FIRST into three separate components, of which probably only the most southern one is related to the large scale radio structure. The projected linear size of this source is 2.9 Mpc.

B0757+477: The NVSS reveals a strong radio core in this source. The FIRST survey radio map shows that the northern lobe has a compact hotspot and that the southern lobe is diffuse. The core is unresolved by FIRST and coincides with a 15.5 mag star-like object. The optical spectrum is dominated by strong and broad Hydrogen Balmer lines and a blue non-thermal continuum. The redshift is 0.1567, resulting in a projected linear size of the radio source of 1.3 Mpc.

B0801+741: The 1.4-GHz WSRT observations of this source reveal a compact core, coinciding with a 15.8 mag optical galaxy. The radio lobes are largely resolved out, however. The NVSS map suggests that these lobes are narrow and straight. The redshift of the host galaxy is 0.1204, and its sepctrum reveals H$\alpha$, [N II]6548/6583 and [S II]6717/6738 emission lines. The H$\beta$ emission line is weak, relative to H$\alpha$, suggesting a large amount of extinction towards the line-emitting gas. The projected linear size of the radio source is 1.1 Mpc.

B0809+454: In the WENSS and NVSS this source is a rather weak ${\sim}7\hbox{$^\prime$ }$-large radio source. The FIRST survey radio map shows the radio core and the two outer extremities of the radio lobes which contain hotspots. The radio core coincides with a 18.5 mag optical source, whose spectrum shows strong [O III]4959,5007 and [O II]3727 emission lines. The redshift is 0.2204, yielding a projected linear size of 1.9 Mpc.

B0813+758: This source has originally been selected from the NVSS, in which it is an 8.5'-large radio source with a bright unresolved central source and an asymmetrical radio structure. A short 1.4-GHz WSRT observation shows that the the eastern radio lobe has a rather strange structure. Higher quality VLA data confirm that all structures on the WSRT map are part of a single large radio lobe (Lara et al. 2001). The central radio source coincides with a 17.5 mag galaxy whose optical spectrum shows strong emission lines. The H$\alpha$-line has a broad component. We measure a redshift of 0.2324, resulting in a linear size of the radio source of 2.3 Mpc.

B0905+352: This $6.3\hbox{$^\prime$ }$-large radio source shows no significant structure in WENSS or NVSS. FIRST, however, reveals that the two radio lobes have strong hotspots, and that the western lobe has an extension towards the north-west. No radio core is detected. Two bright compact objects halfway the two radio lobes were identified as stars, and only the galaxy surrounded by the dashed circle in Fig. .12 was found to show a galaxy-like spectrum, although we have not yet firmly established its redshift. The two lines indicated as [N II] in the spectrum coincide with atmospheric OH-bands. If they are real, the redshift is 0.106, which is rather low considering that the galaxy has a POSS-E magnitude of 18.0. A redshift of 0.260 can also be argued, because of a possible 4000 Å-break observed at a wavelength of 5050 Å. This higher redshift would agree more closely with the optical magnitude of the galaxy.

B0925+420: This source is one of the so-called "Double-double'' radio galaxies (see Schoenmakers et al. 2000a), consisting of two separate double-lobed radio structures. Radio maps, optical images and further information are presented in Schoenmakers et al. (2000a).

B0935+743: This source has a radio morphology much resembling that of the known giant radio galaxy 4CT74.17 (e.g. van Breugel & Willis 1981). The central source coincides with an optical galaxy of 14.3 mag. The optical spectrum shows no signs of emission lines. A somewhat higher resolution observation shows that the central source has two jet-like features pointing towards the outer two sources (Lara et al. 2001), which suggests that all three are part of a single radio structure. The redshift of the optical galaxy associated with the radio core is 0.1215, yielding a projected linear size of 1.3 Mpc.

B1029+281: Because of the low declination of this source, the WENSS radio map does not show much structure. The NVSS map shows a large double-lobed radio source with a relatively strong radio core. The central source is resolved by FIRST into a compact source coinciding with a 14.3 mag optical galaxy, and a radio lobe-like feature at a distance of ${\sim}1\hbox{$^\prime$ }$ to the north. This much resembles the structure observed in the so-called "double-double'' radio galaxies (Schoenmakers et al. 2000a). The optical spectrum of the host galaxy shows strong and broad H$\alpha$ emission. The H$\beta$ emission line also has a broad component. Also, it is much weaker than H$\alpha$ which may indicate a high amount of internal extinction. The redshift is 0.0854, yielding a projected linear size of 1.4 Mpc.

B1044+745: Although this radio source is clearly detected in the NVSS, it is not in the WENSS. The NVSS radio map shows two diffuse lobe-like structures with a weak, compact source in between. The compact source coincides with a 14 mag galaxy. The optical spectrum of this galaxy is dominated by stellar continuum, with only a weak [N II]6584 emission-line. The redshift is 0.1210, and the projected linear size of the radio source is thus 1.9 Mpc.

B1110+405: A FIRST radio map of this $12\hbox{$^\prime$ }$-large radio source shows a relatively bright component in the western radio lobe which resembles a small edge-brightened radio lobe. However, there also is diffuse radio emission at much a larger distance from the radio core. The radio core is identified with a 11.4 mag galaxy, which appears to be double. However, the western optical object is spectroscopically identified as a star. The optical spectrum of the galaxy shows stellar continuum and weak [N II]6584 and [S II]6717/6731 emission lines although the latter lie in an atmospheric absorption band. The projected linear size of the radio source is 1.4 Mpc.

B1144+352: This source is extensively discussed elsewhere (Schoenmakers et al. 1999b).

B1213+422: The radio map from the FIRST survey shows two extended radio lobes and an unresolved central radio source, which coincides with a 15.9 mag galaxy. Its optical spectrum shows strong [O III]4959,5007 emission lines and stellar continuum. The H$\alpha$-line is clearly broadened. The redshift is 0.2426 and the projected linear size is 1.5 Mpc.

B1245+676: This ${\sim}12\hbox{$^\prime$ }$-large radio source has an inverted spectrum radio core, which is identified with a 14 mag galaxy. An optical spectrum of this source can be found in Marcha et al. (1996); it shows no sign of emission lines. The redshift is 0.1073, and the projected linear size of the radio source is therefore 1.8 Mpc. A more detailed analysis of the radio structure of this source will be presented in de Bruyn et al. (in preparation).

B1306+621: This ${\sim}9\hbox{$^\prime$ }$-large radio source is rather faint. The WENSS and NVSS radio maps show two radio lobes and a radio core. A 1.4-GHz WSRT observation shows that both lobes are edge-brightened. The radio core coincides with a 16 mag galaxy, which does not show any emission-lines, though. The redshift is 0.1625, yielding a projected linear size of 1.9 Mpc.

B1310+451: On an angular scale, this is the largest radio source we have found. It has a size of ${\sim}23\hbox{$^\prime$ }$ and contains a bright central core and two diffuse outer lobes. The bright compact source just beyond the western lobe is most likely an unrelated radio source. In the FIRST survey, the radio core is resolved and two jets are visible. The radio core coincides with a 10 mag galaxy. The optical spectrum shows that it has weak [N II]6584 and [S II]6717/6731 emission lines. It has a redshift of 0.0358, yielding a projected linear size of 1.4 Mpc. The existence of the large scale radio emission and the redshift of this radio source have been reported earlier by Faulkner (1985).

B1416+380: This ${\sim}7\hbox{$^\prime$ }$-large radio source resembles a fat double radio source. The northern radio lobe is barely detected in the NVSS. The integrated spectral index of the whole source between 325 and 1400 MHz is -1.46, which makes this radio source the steepest spectrum radio source in our sample. The central component is unresolved in the FIRST and it coincides with a 14.5 mag galaxy. The optical spectrum of this galaxy shows [O I]6300, H$\alpha$ and [N II]6548/6584 emission. Its redshift is 0.1350, resulting in a projected linear size of 1.4 Mpc.

B1426+295: The eastern lobe of this ${\sim}15'$-large source is situated near a bright, but unrelated radio source. The FIRST radio map shows an unresolved central object, which coincides with a 13 mag optical galaxy. The optical spectrum of this galaxy shows weak emission lines of [N II]6548/6583, H$\alpha$, which is partly in absorption, and [S II]6717/6731. The redshift is 0.087, resulting in a projected linear size of the radio source of 1.9 Mpc. We remark that spectroscopical observations of the galaxy situated ${\sim}30\hbox{$^{\prime\prime}$ }$ to the north-west of the host galaxy show that it has the same redshift and is therefore most likely part of the same group of galaxies as the host galaxy.

B1450+333: This source is also a "Double-double'' radio galaxy. Radio maps, optical images and further information are presented in Schoenmakers et al. (2000a).

B1543+845: This source has been found in the NVSS maps, before the WENSS maps of this region of the sky became available. It shows an 8'-large double-lobed radio source with a weak central compact source which coincides with an optical galaxy. The identification of the compact radio source as the radio core is confirmed by a higher resolution VLA radio map (Lara et al. 2001). In the optical spectrum, which has been obtained by I.M. Gioia with the 2.2 m telescope of the University of Hawaii on Mauna Kea, we have identified the [O III] 4959/5007 emission lines. We measure a redshift of 0.201, which yields a projected linear size of 2.1 Mpc for the radio source.

B1709+464: This $10\hbox{$^\prime$ }$-large radio source has a diffuse western lobe and a more edge-brightened eastern lobe. The radio core is clearly detected and a map from the FIRST survey shows that this source has a small two-sided structure somewhat resembling the larger scale radio structure. The core coincides with a 10 mag optical galaxy. The spectrum reveals weak [N II]6584 and [S II]6717/6731 emission lines. The redshift of the host galaxy is 0.0368, yielding a projected linear size of 0.59 Mpc. This is therefore not a GRG.

B1736+375: This is a $7\hbox{$^\prime$ }$-large elongated radio structure which in the NVSS map has a dominant central source. It coincides with a 15.9 mag galaxy, whose optical spectrum reveals H$\alpha$ and [N II] emission-lines, although these are situated near a strong atmospheric absorption band. The redshift is 0.1562. The northern radio structure appears to be a small double-lobed source in the NVSS, and at its center a faint optical galaxy is situated. We have no spectrum of this source. The northern structure may be an unrelated radio source. If the whole structure were to be a single radio source, the projected linear size would be 1.4 Mpc.

B1852+507: The NVSS map of this $7\hbox{$^\prime$ }$-large radio source shows two lobes and a central component which coincides with a 12.8 mag galaxy. We have identified the bright nearby optical source as a star. The optical spectrum of the galaxy shows no emission lines. Its redshift is 0.0958, yielding a linear size of the radio source of 1.0 Mpc.

B1911+470: This ${\sim}6\hbox{$^\prime$ }$-large radio source has a dominant central component and a somewhat bent southern radio lobe. The central component coincides with a 12 mag optical galaxy, which has a companion at a distance of ${\sim}30\hbox{$^{\prime\prime}$ }$ to the north-west. The optical spectrum shows a weak [N II]6584 emission-line, but it overlaps with an atmospheric absorption band. Its redshift is 0.0548. The companion has the same redshift and they are therefore most likely also physically close to each other. The projected linear size of the radio source is 0.54 Mpc, and therefore this is not a GRG.

B1918+512: This $7.3\hbox{$^\prime$ }$-large radio source has a FRII-type radio morphology. The eastern "extension'' is an unrelated radio source. A deep 21-cm WSRT observation shows a possibly two-sided jet in this source and a central radio source, probably the radio core. A CCD-image obtained by P. Best with the LDSS imaging spectrograph on the 4.2 m WHT telescope on La Palma shows a faint galaxy close to the core; on the DSS this source is merged with a nearby star. An optical spectrum shows possible emission lines of [O II]3727 and [O III]5007, as well as several absorption features, all in agreement with a redshift of 0.284. We note that the star-like object situated in the "gap'' between the two radio lobes is spectroscopically identified as a star. If the redshift of the host galaxy is correct, the linear size of this radio galaxy is 2.3 Mpc.

B2147+816: This $18\hbox{$^\prime$ }$-large FRII-type radio galaxy has been briefly described before by Saunders (1982), and more recently (and more extensively) by Palma et al. (2000). Both the NVSS and WENSS radio map show the two radio lobes and the central core. The radio core coincides with a 16.5 mag galaxy, which is a member of a small group of three galaxies. The optical spectrum of the identification shows strong emission lines. Its redshift is 0.1457, confirming the values given by Saunders (1982) and Palma et al. (2000). The projected linear size of the radio source is 3.7 Mpc.

 

 

Table A.1: Table with WENSS selected candidate GRGs after removing sources identified as non-GRGs on basis of optical data. Column 1 gives IAU-notation (in B1950.0) of the source name. Columns 2 and 3 give approximate source coordinates in Right Ascension and Declination in B1950.0 coordinates. Column 4 gives the integrated WENSS flux of the source. Column 5 gives the size of the source in arcminutes. Column 6 indicates whether the source is considered a GRG-candidate, for reasons given in Col. 7.

(1)	(2)	(3)	(4)	(5)	(6)	(7)
Source	RA	Dec	S325	Size	Still	Reason/comments
	[h  m  s]	$[\,\hbox{$^\circ$ }~~ \hbox{$^\prime$ }~~ \hbox{$^{\prime\prime}$ }\,]$	[Jy]	$[\, \hbox{$^\prime$ }\,]$	selected?
B0001+342	00 01 10	34 13 00	0.69	12	no	NVSS morphology
B0023+750	00 23 15	75 00 30	0.30	5	yes	NVSS selected, supported by WENSS
B0036+285	00 36 05	28 29 00	1.54	7	no	NVSS and 1.4-GHz WSRT morphology
B0050+433	00 50 10	43 25 00	0.59	12	no	NVSS morphology
B0058+403	00 58 05	40 19 00	1.04	5	no	NVSS morphology
B0119+377	01 19 10	37 44 00	2.29	6	no	NVSS morphology
B0126+426	01 26 45	42 36 00	0.79	13	no	NVSS morphology
B0141+762	01 41 25	76 13 00	0.18	6	yes	NVSS selected, supported by WENSS
B0200+457	02 00 10	45 45 30	0.19	6	yes	NVSS morphology
B0200+678	02 00 30	67 53 00	2.15	6	no	1.4-GHz WSRT morphology
B0201+317	02 01 35	31 42 00	0.15	6	no	NVSS morphology
B0211+326	02 11 20	32 37 00	1.59	5	yes	1.4-GHz WSRT morphology
B0217+367	02 17 20	36 46 00	2.44	16	yes	NVSS morphology
B0330+871	03 30 35	87 07 00	0.11	6	yes	NVSS selected, supported by WENSS
B0334+329	03 34 30	32 59 00	0.54	6	yes	NVSS morphology
B0429+293	04 29 40	29 22 00	1.31	7	no	NVSS morphology
B0503+704	05 03 30	70 27 00	1.01	6	no	NVSS morphology
B0603+612	06 03 00	61 15 00	1.64	5	yes	NVSS morphology
B0627+721	06 27 40	72 11 30	0.77	5	yes	NVSS and 1.4-GHz WSRT morphology
B0634+515	06 34 35	51 30 00	0.36	10	yes	NVSS morphology
B0646+370	06 46 55	37 03 00	0.47	6	no	NVSS morphology
B0648+734	06 48 15	73 23 30	2.4	13	yes	NVSS morphology
B0648+431	06 48 40	43 08 30	0.71	10	yes	NVSS morphology
B0658+490	06 58 20	49 03 30	1.01	19	yes	NVSS morphology
B0713+432	07 13 45	43 14 00	0.59	7	yes	NVSS and FIRST morphology
B0730+375	07 30 00	37 30 00	0.52	10	no	NVSS and FIRST morphology
B0747+426	07 47 40	42 39 00	0.64	6	yes	NVSS/FIRST morphology
B0750+434	07 50 40	43 24 00	0.24	8	yes	NVSS/FIRST morphology
B0757+477	07 57 55	47 44 30	0.25	6	yes	NVSS/FIRST morphology
B0801+741	08 01 15	74 09 00	0.55	6	yes	NVSS selected, supported by WENSS
B0809+454	08 09 40	45 25 00	0.26	7	yes	NVSS and FIRST morphology
B0813+758	08 13 40	75 48 00	2.14	8	yes	NVSS selected, supported by WENSS
B0817+427	08 17 45	42 43 00	1.18	9	no	NVSS and FIRST morphology
B0817+337	08 17 50	33 43 00	0.26	6	no	NVSS and FIRST morphology
B0840+513	08 40 45	51 18 00	0.98	10	no	NVSS and FIRST morphology
B0853+292	08 53 00	29 16 00	3.90	15	no	NVSS and FIRST morphology
B0854+402	08 54 00	40 12 00	0.35	6	no	NVSS and FIRST morphology
B0903+783	09 03 11	78 21 30	0.20	8	no	Western `lobe' overlaps bright spiral galaxy
B0905+352	09 05 45	35 17 30	0.57	6	yes	NVSS and FIRST morphology
B0909+353	09 09 45	35 22 00	0.50	6	yes	NVSS and FIRST morphology
B0917+307	09 17 15	30 42 30	0.46	10	no	NVSS and FIRST morphology
B0925+420	09 25 55	42 00 00	0.55	7	yes	NVSS and FIRST morphology
B0935+743	09 35 00	74 19 00	0.19	7	yes	NVSS selected, supported by WENSS
B0936+512	09 36 40	51 17 30	0.94	6	no	WSRT 1.4-GHz and FIRST morphology
B1001+548	10 01 30	54 48 30	0.52	13	yes	NVSS morphology
B1029+281	10 29 25	28 11 30	0.67	11	yes	NVSS and FIRST morphology
B1029+322	10 29 40	32 12 00	0.64	11	no	WSRT 1.4-GHz and FIRST morphology
B1030+312	10 30 25	31 12 00	0.87	6	no	NVSS and FIRST morphology
B1036+632	10 36 30	63 15 30	0.14	5	yes	NVSS morphology
B1044+745	10 44 15	74 35 30	0.12	11	yes	NVSS selected, supported by WENSS
B1054+488	10 54 10	48 52 30	0.71	8	yes	NVSS and FIRST morphology

 

Table A.1: continued.

(1)	(2)	(3)	(4)	(5)	(6)	(7)
Source	RA	Dec	S325	Size	Still	Reason/comments
	[h  m  s]	$[\,\hbox{$^\circ$ }~~ \hbox{$^\prime$ }~~ \hbox{$^{\prime\prime}$ }\,]$	[Jy]	$[\, \hbox{$^\prime$ }\,]$	selected?
B1110+405	11 10 20	40 34 00	0.82	12	yes	NVSS and FIRST morphology
B1112+333	11 12 15	33 19 00	3.06	6	no	WSRT 1.4-GHz and FIRST morphology
B1144+353	11 44 45	35 18 30	0.97	12	yes	z=0.063 (NED), so $D \sim 1.2$ Mpc
B1150+312	11 50 50	31 12 00	0.28	9	no	NVSS and FIRST morphology
B1209+614	12 09 30	61 04 00	2.54	6	no	4C61.25, NVSS morphology
B1213+422	12 13 40	42 16 00	1.10	5	yes	NVSS and FIRST morphology
B1218+639	12 18 30	63 56 30	1.19	8	no	NVSS morphology
B1232+535	12 32 40	53 35 00	0.36	10	yes	NVSS morphology
B1234+836	12 34 00	83 39 30	0.07	6	yes	NVSS selected, supported by WENSS
B1245+676	12 45 30	67 39 00	0.20	12	yes	NVSS selected, z = 0.1073 (NED), so $D\sim1.8$ Mpc
B1250+452	12 50 45	45 17 00	1.33	10	no	NVSS morphology and bright optical ID
B1306+621	13 06 50	62 10 00	0.19	9	yes	NVSS morphology
B1310+451	13 10 05	45 09 30	0.65	23	yes	z=0.0356 (NED), so $D \sim 1.4$ Mpc
B1330+361	13 30 20	36 09 00	0.27	7	no	NVSS and FIRST morphology
B1340+382	13 40 50	38 15 00	0.34	10	yes	NVSS and FIRST morphology
B1340+447	13 40 55	44 44 00	0.30	6	no	NVSS and FIRST morphology
B1342+407	13 42 30	40 44 00	0.51	8	no	NVSS and FIRST morphology
B1343+371	13 43 45	37 07 00	1.90	7	no	WSRT 1.4-GHz and FIRST morphology
B1404+362	14 04 55	36 15 00	0.24	6	no	NVSS and FIRST morphology
B1415+685	14 15 30	68 33 00	0.26	6	yes	NVSS morphology
B1416+380	14 16 35	38 00 00	0.46	7	yes	NVSS and FIRST morphology
B1426+295	14 26 10	29 32 00	1.10	15	yes	NVSS and FIRST morphology
B1443+310	14 43 20	31 04 00	0.41	7	yes	NVSS and FIRST morphology
B1450+333	14 50 55	33 21 00	1.38	6	yes	NVSS and FIRST morphology
B1532+315	15 32 40	31 35 00	0.73	13	no	NVSS and FIRST morphology
B1535+613	15 35 40	61 22 00	0.09	6	no	NVSS morphology
B1543+845	15 43 55	84 33 00	1.14	8	yes	NVSS selected, supported by WENSS
B1614+485	16 14 25	48 33 00	0.17	10	yes	NVSS and FIRST morphology
B1623+410	16 23 30	41 03 00	1.25	7	no	NVSS and FIRST morphology
B1634+503	16 34 15	50 23 00	0.59	7	no	NVSS and FIRST morphology
B1637+539	16 37 50	53 55 00	1.99	9	no	NVSS and FIRST morphology
B1639+328	16 39 05	32 50 00	0.90	6	no	NVSS and FIRST morphology
B1709+464	17 09 30	46 28 00	1.11	10	yes	NVSS and FIRST morphology
B1736+375	17 36 40	37 35 00	0.48	7	yes	NVSS morphology
B1838+658	18 38 05	65 52 00	0.95	7	yes	NVSS; z=0.23 (NED), so $D \sim 1.9$ Mpc.
B1844+653	18 44 00	65 19 10	0.26	7	yes	NVSS morphology
B1852+507	18 52 20	50 42 00	0.27	7	yes	NVSS morphology
B1855+310	18 55 20	31 00 00	1.35	9	yes	NVSS morphology
B1911+470	19 11 50	47 01 00	0.80	6	yes	NVSS morphology
B1911+481	19 11 50	48 09 00	0.77	16	yes	NVSS morphology
B1918+453	19 18 40	45 22 00	0.78	18	yes	NVSS morphology
B1918+516	19 18 05	51 36 00	1.22	7	yes	NVSS morphology
B1919+479	19 19 55	47 59 30	3.52	10	yes	4C47.51, z=0.102 (NED), so $D\sim1.5$ Mpc
B1919+741	19 19 15	74 09 30	2.04	6	yes	NVSS morphology
B1924+549	19 24 30	54 59 00	0.48	7	no	NVSS morphology
B2130+341	21 30 05	34 07 00	0.37	6	yes	NVSS morphology
B2147+816	21 47 20	81 41 00	1.06	18	yes	NVSS selected, supported by WENSS
B2205+376	22 05 25	37 36 00	0.32	7	yes	NVSS morphology
B2231+320	22 31 10	32 00 00	0.29	11	no	NVSS morphology
B2233+373	22 33 20	37 20 00	0.62	6	yes	NVSS morphology
B2312+419	23 12 40	41 57 10	0.27	6	no	NVSS morphology
B2315+401	23 15 55	40 10 17	0.11	6	yes	NVSS morphology
B2326+315	23 26 00	31 35 00	0.47	10	no	NVSS morphology
B2357+401	23 57 10	40 08 00	0.22	5	yes	NVSS morphology

 

 

Table A.2: Log of the spectroscopic observations of GRG candidates in our sample. Column 1 gives the name of the source in IAU format. Column 2 gives the telescope used for the observations. Column 3 gives the observing date. Column 4 gives the central wavelength of the observation in Ångstrom (for the INT only). Column 5 gives the used width of the slit in arcsec. Column 6 gives the integration time. Column 6 gives an indication of the observing conditions; "P'' stands for photometric conditions, "NP'' for non-photometric conditions, or cirrus clouds, and "C'' stands for cloudy conditions.

(1)	(2)	(3)	(4)	(5)	(6)	(7)
Source	Tel.	Date	$\lambda_{\rm central}$	Slit	Int.	Cond.
			$[\,$Å$\,]$	$[\,\hbox{$^{\prime\prime}$ }\,]$	$[\,$s$\,]$
B0211+326	INT	4 Aug. 1995	6000	2	2400	NP
		8 Oct. 1996	6500	2	1200	P
B0217+367	INT	4 Aug. 1995	5500	2	900	C
B0648+733	INT	6 Apr. 1996	6000	2	1800	P
B0648+431	INT	7 Apr. 1996	6000	2	1200	NP
B0658+490	INT	6 Apr. 1996	6000	2	1800	P
B0747+426	INT	8 Oct. 1996	6000	2	1200	P
B0750+434	INT	9 Oct. 1996	6000	2	600	P
			6500	2	600	P
B0757+477	INT	7 Apr. 1996	5500	2	600	NP
			6500	2	600	NP
B0801+741	INT	7 Apr. 1996	6000	2	600	NP
B0809+454	INT	8 Apr. 1996	6000	3	600	NP
			6500	3	600	NP
B0813+758	INT	6 Apr. 1996	6000	2	600	P
			6500	2	1200	P
B0905+352	INT	7 Apr. 1996	6000	2	600	NP
B0925+420	INT	8 Apr. 1996	6000	2	600	NP
B0935+743	INT	7 Apr. 1996	6000	2	1200	NP
B1029+281	INT	7 Apr. 1996	6000	2	1200	NP
B1044+745	INT	7 Apr. 1996	6000	2	600	NP
B1110+405	INT	6 Apr. 1996	6000	2	1200	P
B1213+422	INT	7 Apr. 1996	6000	2	600	NP
			6500	2	600	NP
B1306+621	INT	8 Apr. 1996	6000	2	1200	NP
B1310+451	INT	5 Aug. 1995	5500	2	900	P
B1416+380	INT	5 Aug. 1995	6000	2	900	P
		9 Apr. 1996	6500	2	600	P
B1426+295	INT	4 Aug. 1995	5500	2	1800	P
		9 Apr. 1996	6000	2	1200	P
B1450+333	WHT	8 July 1997		2	600	P
B1543+845	2.2m UH	4 Mar. 1998		2	2100	P
		5 Mar. 1998		2	2400	P
B1709+464	INT	4 Aug. 1995	5500	2	900	P
B1736+375	INT	9 Oct. 1996	6000	2	1200	P
B1852+507	INT	9 Oct. 1996	6000	2	600	P
B1911+470	INT	8 Oct. 1996	6000	2	1200	P
B1918+516	INT	8 Oct. 1996	6000	2	600	P
B2147+816	INT	9 Oct. 1996	5500	2	600	P
			6000	2	1200	P

  

Table A.3: Properties of the radio cores and the optical identifications of the spectroscopically observed sources, and of the confirmed giant sources B1144+352, B1245+676 and B1310+451. Column 1 gives the name of the radio source in IAU notation; Col. 2 gives the observation used to determine the radio core position and its flux density; Cols. 3 and 4 give the radio core position in right ascension and declination, respectively, in B1950.0 coordinates. These have been obtained by fitting a Gaussian in the radio map. Column 5 gives the integrated flux density at 1.4 GHz of the radio core. Columns 6 and 7 give the position of the optical identification in right ascension and declination, respectively, in B1950.0 coordinates, obtained from fitting a Gaussian in the available optical image. Column 8 gives the magnitude of the identification in the red (POSS-E) band of the Palomar survey. The magnitudes for sources weaker than 15.0 have been obtained from the APM catalogue and are estimated to be accurate to 0.5 mag. For brighter sources, we have measured the magnitudes directly from the digitized POSS-I frames using the photometric calibration for stars available from the STScI WWW-pages and through the GETIMAGE-2.0 plate retrieval software. Typical uncertainties in these values are estimated to be large, at least 1 mag.

$$\begin{tabular}{l l l@{$\,\pm\,$}r l@{$\,\pm\,$}r r@{$\,\pm\,... ...1 & 81 40 57.3 & 0.1 & 16.5 \\ \hline \hline \\ \end{tabular}$$

Notes:
a-Variable (see Schoenmakers et al. 1999b).
b-Merged with nearby star on DSS; the magnitude has been determined by subtracting the flux from the star, obtained by fitting a Gaussian, from the integrated flux of the star and galaxy combined. The error is therefore large (estimated at 1 mag).

  

Table A.4: Radio properties of the sources from Table .3. Column 1 gives the source name in IAU format. Column 2 gives the integrated flux density of the source at 325 MHz from the WENSS (unless states otherwise). Column 3 gives the integrated flux density at 1400 MHz from the NVSS. Column 5 gives the spectral index between 325 and 1400 MHz. Column 6 gives the redshift of the host galaxy. Column 7 gives the angular size of the radio source in arcminute. Column 8 gives the projected linear size in Mpc. Column 9 gives the radio luminosity at an emitted frequency of 325 MHz.

$$\begin{tabular}{l r@{$\,\pm\,$}l r@{$\,\pm\,$}l l@{$\,\pm\,$}... ...& 3.66 & 0.04 & 26.00 & 0.02 \\ \hline \hline\\ \end{tabular}$$

Notes:
a-Subtracted $41 \pm 7$ mJy background object at RA 06 49 02.7, Dec 73 25 55.
b-Subtracted $19.8 \pm 1.1$ mJy background object at RA 06 49 02.7, Dec 73 25 55.
c-Subtracted $149 \pm 11$ mJy background object at RA 07 47 48.2, Dec 42 39 56.
d-Subtracted $26 \pm 1$ mJy background object at RA 07 47 48.2, Dec 42 39 56.
e-See Schoenmakers et al. (2000a) for radio maps and optical spectrum of this source.
f-Includes background source at RA 10 29 36.3 Dec 28 13 15.9 (flux density $10 \pm 1$ mJy at 1400 MHz).
g-WENSS polar cap region (observed frequency 351 MHz).
h-Subtracted $72 \pm 7$ mJy background object at RA 11 10 24.8, Dec 40 38 03.
i-See Schoenmakers et al. (1999b) for radio maps and optical spectrum of this source.
j-Colla et al. (1975).
k-Marcha et al. (1996).
l-Subtracted $90\pm7$ mJy background source at RA 19 18 17.1, Dec 51 37 53.
m-Subtracted $26 \pm 1$ mJy background source at RA 19 18 17.1, Dec 51 37 53.
n-Uncertain redshift.

   

Table A.5: The measured wavelengths and resulting redshifts of the most prominent emission and absorption lines. Column 1 gives the name of the source, Col. 2 the used line, Col. 3 the measured wavelength, i.e. the position of the peak of the Gaussian used in fitting the line, and Col. 4 the therefrom derived redshift of that line. The last line for each source gives the average redshift.

(1)	(2)	(3)	(4)
Source	Line	$\lambda_{\rm peak}/[$Å]	Redshift
B0211+326	[O II]3727	4697.04	0.2603
	[Ne III]	4877.16	0.2606
	H$\beta$	6127.18	0.2605
	[O III]4959	6250.79	0.2605
	[O III]5007	6311.32	0.2605
			0.2605$\,\pm\,$0.0002
B0217+367	Ca II3934	4078.60	0.0368
	Ca II3968	4115.06	0.0371
	G-band	4462.41	0.0366
	Mg-b	5364.99	0.0367
	Na D	6110.44	0.0369
			0.0368$\,\pm\,$0.0003
B0648+733	G-band	4798.18	0.1146
	H$\beta$	5417.93	0.1146
	[O III]4959	5527.37	0.1146
	[O III]5007	5580.97	0.1146
	Mg-b	5766.97	0.1144
	[O I]6300	7020.84	0.1144
	[N II]6583	7336.42	0.1144
			0.1145$\,\pm\,$0.0002
B0648+431	G-band	4688.06	0.0890
	Mg-b	5636.05	0.0891
	Na D	6418.92	0.0892
			0.0891$\,\pm\,$0.0002
B0658+490	Mg-b	5511.23	0.0650
	Na D	6275.81	0.0650
	[N II]6583	7010.76	0.0650
			0.0650$\,\pm\,$0.0002
B0747+426a	[O II]3727	4483.93	0.2031
	Ca II3934	4731.23	0.2027
	Ca II3968	4772.31	0.2027
	G-band	5178.74	0.2030
	Mg-b	6228.69	0.2036
			0.2030$\,\pm\,$0.0004
B0750+434	[Ne V]3426	4615.94	0.3473
	[O II]3727	5022.40	0.3476
	[Ne III]3869	5211.82	0.3471
	[O III]4363	5879.17	0.3475
	H$\beta$	6550.15	0.3475
	[O III]4959	6681.97	0.3474
	[O III]5007	6746.39	0.3474
			0.3474$\,\pm\,$0.0003

(1)	(2)	(3)	(4)
Source	Line	$\lambda_{\rm peak}/[$Å]	Redshift
B0757+472	H$\gamma$	5019.76	0.1566
	H$\beta$	5622.10	0.1566
	[O III]4959	5736.78	0.1568
	[O III]5007	5792.23	0.1568
			0.1567$\,\pm\,$0.0002
B0801+741	H$\beta$	5446.74	0.1205
	[O III]5007	5610.22	0.1205
	Na D	6603.31	0.1205
	[O I]6300	7058.78	0.1204
	H$\alpha$	7351.97	0.1202
	[S II]6583	7524.50	0.1204
			0.1204$\,\pm\,$0.0002
B0809+454	[O II]3727	4548.56	0.2204
	H$\beta$	5933.56	0.2206
	[O III]4959	6052.08	0.2204
	[O III]5007	6109.84	0.2203
	H$\alpha$	8007.07	0.2200
			0.2204$\,\pm\,$0.0003
B0813+758	[O II]3727	4591.00	0.2318
	H$\beta$	5989.61	0.2322
	[O III]4959	6111.66	0.2324
	[O III]5007	6170.54	0.2324
	[O I]6300	7766.57	0.2328
	H$\alpha$	8089.26	0.2326
			0.2324$\,\pm\,$0.0003
B0905+352	[N II]6548	7242.29	0.1059
	[N II]6583	7279.51	0.1058
			0.106$\,\pm\,$0.001
or
	G-band	5422.53	0.2596
	Mg-b	6512.59	0.2585
			0.260$\,\pm\,$0.002
B0935+743	Ca II3968	4448.92	0.1212
	Mg-b	5806.05	0.1219
	Na D	6608.56	0.1214
			0.1215$\,\pm\,$0.0003
B1029+281	H$\beta$	5274.68	0.0851
	[O III]4959	5382.18	0.0853
	[O III]5007	5434.69	0.0854
	Mg-b	5618.53	0.0857
	Na D	6397.44	0.0856
	[O I]6300	6837.35	0.0853
	H$\alpha$	7121.47	0.0851
			0.0854$\,\pm\,$0.0002
B1044+745a	Ca II3968	4448.36	0.1211
	Mg-b	5800.85	0.1209
	Na D	6606.56	0.1211
			0.1210$\,\pm\,$0.0003

 

Table A.5: continued.

(1)	(2)	(3)	(4)
Source	Line	$\lambda_{\rm peak}/[$Å]	Redshift
B1110+405	G-band	4625.03	0.0743
	Na D	6332.42	0.0746
	[N II]6583	7073.81	0.0746
			0.0745$\,\pm\,$0.0003
B1213+422	[O II]3727	4632.22	0.2429
	[Ne III]3869	4806.84	0.2424
	[O III]4363	5422.13	0.2428
	H$\beta$	6041.38	0.2428
	[O III]4959	6162.09	0.2426
	[O III]5007	6221.83	0.2426
	[O I]6300	7828.06	0.2425
	H$\alpha$	8154.30	0.2425
			0.2426$\,\pm\,$0.0002
B1306+621a	Ca II3934	4574.07	0.1627
	Ca II3968	4612.79	0.1625
	G-band	5003.63	0.1623
	Mg-b	6016.99	0.1627
			0.1625$\,\pm\,$0.0004
B1310+451	Ca II3934	4075.03	0.0358
	Ca II3968	4110.96	0.0360
	G-band	4458.96	0.0358
	Mg-b	5359.83	0.0357
	Na D	6102.51	0.0356
	[N II]6583	6817.81	0.0357
			0.0358$\,\pm\,$0.0002
B1416+380	Mg-b	5874.33	0.1351
	Na D	6688.00	0.1349
	[O I]6300	7150.68	0.1350
	H$\alpha$	7448.93	0.1350
	[N II]6583	7471.70	0.1350
			0.1350$\,\pm\,$0.0002
B1426+295	G-band	4678.63	0.0868
	[O III]4363	4742.83	0.0871
	H$\beta$	5283.63	0.0869
	Mg-b	5627.45	0.0874
	Na D	6403.01	0.0865
	[N II]6583	7156.50	0.0871
			0.0870$\,\pm\,$0.0003

(1)	(2)	(3)	(4)
Source	Line	$\lambda_{\rm peak}/[$Å]	Redshift
B1543+845a	[O III]4959	5955.22	0.2009
	[O III]5007	6013.78	0.2011
			0.201$\,\pm\,$0.001
B1709+464	Ca II3968	4114.19	0.0368
	G-band	4463.67	0.0369
	Mg-b	5366.13	0.0369
	Na D	6108.30	0.0365
	[N II]6583	6824.31	0.0367
			0.0368$\,\pm\,$0.0002
B1736+375	Ca II3968	4548.75	0.1563
	Mg-b	5984.90	0.1565
	Na D	6811.76	0.1559
			0.1562$\,\pm\,$0.0003
B1852+507	G-band	4717.29	0.0958
	Mg-b	5670.70	0.0958
	Na D	6457.09	0.0957
			0.0958$\,\pm\,$0.0003
B1911+470	G-band	4540.16	0.0546
	Mg-b	5457.87	0.0547
	Na D	6216.32	0.0549
	[N II]6583	6944.73	0.0549
			0.0548$\,\pm\,$0.0002
B1918+512	Ca II3968	5050.42	0.2838
	[O III]5007	6425.44	0.2833
			0.284$\,\pm\,$0.001
B2147+816	[O II]3727	4270.15	0.1457
	[Ne III]3869	4432.08	0.1455
	H$\gamma$	4972.15	0.1457
	[O III]4363	4998.67	0.1457
	H$\beta$	5568.67	0.1456
	[O III]4959	5681.59	0.1457
	[O III]5007	5736.42	0.1457
			0.1457$\,\pm\,$0.0001

Notes:
a-Spectrum has been smoothed with a 3 pixel rectangular box.

  

Table A.6: The flux density levels of the first contour in the presented radio contour maps. Column 1 gives the name of the source; Cols. 2 to 5 give the flux density of the first contour in the radio contour plots of the WENSS, NVSS, FIRST and WSRT radio map. Column 6 gives the beam size of the WSRT beam in cases where a WSRT radio map is presented. Column 7 gives the origin of the presented optical images. Here, PI stands for POSS-I, PII for POSS-II; LDSS is an imaging spectrograph on the 4.2-m WHT on La Palma, HARIS is an imaging spectrograph on the 2.2-m University of Hawaii telescope on Mauna Kea. Unless indicated otherwise, contour levels have been plotted at -1,1,2,4,8,16,32,64,128,256 times the flux density level presented in this table.

$$\begin{tabular}{l c l l l l@{$\,\times\,$}r l} \hline \hline... ...3 & & & \multicolumn{2}{c}{\ } & PII \\ \hline % \end{tabular}$$

Notes:
a-Extra contour plotted at a level of $\sqrt2$ times the lowest contour level.

Figure A.1: B0211+326: The WENSS radio contour plot, an overlay of the WSRT radio map (contours) with an optical image (grey scale; the identification has been encircled) and the optical spectrum of the host galaxy.

Figure A.2: B0217+367: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.3: B0648+733: The WENSS (left) and NVSS (right) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.4: B0648+431: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.5: B0658+490: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.6: B0747+426: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale; the identification has been encircled) and the optical spectrum of the host galaxy.

Figure A.7: B0750+434: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.8: B0757+477: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.9: B0801+741: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.10: B0809+454: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.11: B0813+758: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.12: B0905+352: The WENSS radio contour plot, an overlay of the FIRST radio map (contours) with an optical image (grey scale; the identification has been encircled) and the optical spectrum of the host galaxy.

Figure A.13: B0935+352: The WENSS radio contour plot, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.14: B1029+281: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.15: B1044+745: The WENSS radio contour plot, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.16: B1110+405: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.17: B1213+422: The WENSS radio contour plot, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.18: B1245+676: The WENSS radio contour plot and an overlay of the NVSS radio map (contours) with an optical image (grey scale). An optical spectrum has been published by Marcha et al. (1996).

Figure A.19: B1306+621: The WENSS (left) and NVSS (right) radio contour plots, an overlay of the WSRT radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.20: B1310+451: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.21: B1416+380: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.22: B1426+295: The WENSS (left) and NVSS (right) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.23: B1543+845: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.24: B1709+464: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the FIRST radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.25: B1736+375: The WENSS radio contour plot, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy of the central source; note the fuzzy optical object near the center of the northern radio component.

Figure A.26: B1852+507: The WENSS radio contour plot, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.27: B1911+470: The WENSS radio contour plot, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.

Figure A.28: B1918+516: The WENSS radio contour plot, an overlay of the 1.4-GHz WSRT radio map (contours) with an optical image (grey scale; the identification is indicated by the arrow) and the optical spectrum of the host galaxy.

Figure A.29: B2147+816: The WENSS (upper) and NVSS (lower) radio contour plots, an overlay of the NVSS radio map (contours) with an optical image (grey scale) and the optical spectrum of the host galaxy.