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High Redshift USS 4C Sources

The high redshift objects discussed in this paper are a subset of the 4C USS sample described in Chambers et al. 1987 and Paper I. This subset is those objects that we have found to have redshifts . All the faint extended objects in the USS 4C sample were observed spectroscopically but the objects with the strongest emission lines are the most likely to have had their redshifts determined. Objects in the range are less likely to have their redshifts determined because no strong emission lines are redshifted into the observed bandpass. Many of the spectroscopically unidentified sources in Paper I have faint optical identifications and are likely to be additional high redshift objects. The sample of eight objects presented here is probably biased towards objects with strong emission lines.

In Table 1 we list the high redshift 4C USS sources, redshifts, R magnitude, and integrated radio properties. Offset stars and their coordinates are also listed. Finder charts for the 6 previously unidentified high redshift objects are shown in Figure 1, finder charts for the other two objects, 4C41.17 and 4C40.36, are in Chambers et al. 1988 and Chambers et al. 1990. Table 2 contains the radio total intensity and polarization photometry. These are summarized in plots of the radio spectra of the individual components of each source in Figure 2. Table 3 lists details of the optical and infrared photometry.

The registered images of the radio total intensity, radio polarization, infrared, optical broad band, and narrow band emission are shown in Figures 3,4,5,6,7,8,9, and 10. When the radio morphology is simple then we designate the western lobe as lobe A, the eastern lobe as lobe B, and if an unambiguous core is detected it is labeled C. Sub-components are given a numerical subscript. In the same manner as Paper I we show both polarization and total intensity maps and in our discussion of the radio polarization data we use strongly depolarized for objects with a small depolarization measure DP = P20/P6 and weakly depolarized for objects with a large DP. The registration of the optical data with the radio data is crucial to examine the relationship between the radio and optical emission. To emphasize the relationships of all the different kinds of data each panel in the figures has been carefully scaled and registered with the other panels for that object (to within the astrometric accuracy discussed above). The interested reader is encouraged to reproduce each figure on a transparency so that the panels can be overlaid. To aid in the presentation of the data we also include enlarged subsections of certain images. In sections 3.1 through 3.8 below we discuss each individual high redshift object in order of right ascension.




Next: 4C60.07 Up: Ultra Steep Spectrum Radio Previous: Spectroscopy


M.Bremer@sron.ruu.nl
Wed May 29 16:34:20 MET DST 1996