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2. The sample

2.1. Definition of the sample

The sample is defined as follows:

Part 1: 233 sources with tex2html_wrap_inline2628 (hereafter on the Baars et al. 1977 scale) within the B(1950) sky coordinates: tex2html_wrap_inline2630, tex2html_wrap_inline2632 and tex2html_wrap_inline2634, tex2html_wrap_inline2636. Sky area of 0.4414 sr.

Part 2: 109 sources with tex2html_wrap_inline2638 within tex2html_wrap_inline2640, tex2html_wrap_inline2642, tex2html_wrap_inline2644, tex2html_wrap_inline2646, and
tex2html_wrap_inline2648, tex2html_wrap_inline2650. Sky area of 0.0906 sr.

Part 3: 31 sources with tex2html_wrap_inline2652 within tex2html_wrap_inline2644, tex2html_wrap_inline2646, and
tex2html_wrap_inline2648, tex2html_wrap_inline2650. Sky area of 0.0550 sr.

All the sources have tex2html_wrap_inline2662. Hereafter these parts are referred to as Subsample 1, 2, and 3, respectively.

2.2. Mean weighted 1.4-GHz flux density

For all the sample sources their two independent measurements of 1.4 GHz flux density resulting from the Green Bank surveys GB/GB2 (Maslowski 1972; Machalski 1978a) and 83GB (Condon & Broderick 1985; the relevant catalogue by White & Becker 1992) were compared with the measured VLA flux density (cf. Introduction). That comparison allowed to select either confused sources requiring flux correction or heavily resolved sources for further reobservations with lower resolution. Some of the confused sources appeared to be two different ones but still satisfying the criteria of the sample. Recently D-array and B-array maps for several of the sample sources have become available from the large VLA 1.4-GHz sky surveys: FIRST by Becker et al. (1995) and Condon et al. (1996). These were also used to check the effects of resolution in our data.

For many of the sources, additional 1.4 GHz fluxes were also available from observations with the Effelsberg 100 m telescope (Kühr et al. 1981) and Arecibo 300 m telescope (Owen et al. 1983); some fluxes for compact sources were available from measurements with the WSRT and Cambridge One-mile (OMT) telescopes. All collected 1.4 GHz flux densities, corrected for confusion if necessary, were then used to compute the weighted mean flux density at this frequency, tex2html_wrap_inline2664, and its error, tex2html_wrap_inline2666, with the standard formulae
The mean 1.4-GHz flux density was used to verify completeness of the sample.

2.3. Completeness of the sample

In order to satisfy the conditions given in Sect. 2.1, 12 sources from Paper I and 20 sources observed in Papers IV and V have been excluded from the sample. They are listed in Table 1 (click here) with information about the cause of exclusion. In turn, 15 sources have been added to the sample because they were underestimated in the finding surveys due to a large flux density error but their mean 1.4-GHz flux density calculated from all available observations
(cf. Sect. 2.2) satisfied the selection criterion. These additional sources are indicated by a diamond mark tex2html_wrap_inline2668 preceding the source name in Table A3 (click here). Due to the above corrections, we estimate that now the sample is about 99 per cent complete for sources with tex2html_wrap_inline2628, about 97 per cent complete for sources with tex2html_wrap_inline2638, and about 95 per cent complete for sources with
tex2html_wrap_inline2652. The completeness is evaluated using the method of Dixon & Kraus (1968).


Source Cause Source Cause Source Cause Note
0724+467 tex2html_wrap_inline2676 0719+362 2 sources 1137+493 tex2html_wrap_inline2678
0738+336 2 sources 0728+364 2 sources 1202+488 cluster
0908+340 2 sources 0846+377 2 sources 1204+483 2 sources
0913+471 tex2html_wrap_inline2676 0851+363 2 sources 1205+500 2 sources
0914+502 tex2html_wrap_inline2676 0902+480 2 sources 1225+498 2 sources
1112+333 2 sources 0910+486 tex2html_wrap_inline2678 1316+346 tex2html_wrap_inline2686
1135+464 2 sources 0954+490 2 sources 1401+350 cluster a)
1317+362 2 sources 0955+492 3 sources 1533+345 cluster
1432+382 3 sources 1042+481 tex2html_wrap_inline2678 1539+350 tex2html_wrap_inline2686
1442+363 2 sources 1124+488 cluster 1648+350 2 sources
1614+473 tex2html_wrap_inline2676
1615+352 part of 1615+351?
Table 1: (left panel): Sources excluded from the Part 1 (list of Machalski & Maslowski 1982); (central and right panel): excluded from the Part 2 and Part 3 (lists of Machalski & Condon 1983b, 1985)

a) given in Machalski & Condon (1990).

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