5 Results

Table 5 with the results of observations is available in the electronic form only at the CDS via anonymous ftp. It includes the flux density data (with one sigma errors without scale errors $\sigma^{r}_{scale}$) at 1.4, 2.7, 3.9, 7.7, 13 and 31 cm for 546 of 551 objects of the source list from Table 1. Instantaneous observations of the spectra are shown at Fig. 4. Averaged instantaneous spectra are given in Table 5 and Fig. 4, if two or more observations of a source have been done.

The sources 0156-14, 1635-03 were not observed in December, 1997. We have pointed the antenna to the coordinates of 0611+13 several times, but we have not detected an emission from the source at any frequency (nothing is present at the coordinates of 0611+13 in NED too). The object 3C 274 is resolved by RATAN-600 at all observed frequencies; multifrequency response to 3C 111 has a double maximum. We have excluded the data for these sources from final results.

Absence of data for some sources at some frequencies is a result, in general, of data exclusion for the following reasons: possible confusion in declinations (especially at low elevations) or partial resolution of a source at some frequencies (e.g. 3C 154 at 1.4, 2.7, 3.9, 7.7 cm), a source is too weak to be measured reliably (e.g. III Zw 2 at 31 cm), a strong influence of man-made interferences (frequently at 31 cm, sometimes at 13 cm), strong interferences from a stationary placed satellite at 2.7 and 7.7 cm (in declinations between $-10^\circ$and $0^\circ$). Nevertheless, in some cases the data was not excluded in spite of the increase in errors caused usually by interferences.

We believe that shapes of the instantaneous spectra presented can be explained by continuous activity of the nuclei of the objects in accordance with the basic hypothesis of a source with two dominating general components (compact and extended), following Kovalev et al. (1996), Kovalev & Kovalev (1996). The detailed analysis of the data is deferred to later papers.

Acknowledgements

We would like to thank the RATAN-600 staff for technical support of the observational process. Some of our problems in achieving the twenty four hour observations were resolved through the valuable assistance of Ira Morozova. We are obliged to Harry Teräsranta for providing us with the unpublished data of 22 GHz Metsähovi observations to check our calibration at this frequency, to Greg Taylor for observing the object 0237-23 at our request at the VLA in 1998 and 1999 in order to study known high frequency discrepancy of the source spectrum, and to Vladimir Amirkhanyan for kindly making his routine on simulating the RATAN-600 beam available at our disposal. We thank Tanya Downs and an anonymous referee for carefully reading the manuscript and for valuable comments. YYK and YAK are grateful to the administration and employees of the observatory for their hospitality during the visit for carrying out the observations. This work has been partly supported by the Russian State Program "Astronomy" (grant 1.2.5.1). YYK acknowledges support from International Soros Science Educational Program grants a97-2965, a98-1932 and a99-1882. This research has made use of the NASA/IPAC Extragalactic database (NED), which is operated by the Jet Propulsion Laboratory, Caltech, under contract with the National Aeronautic and Space Administration.