SPECTRA OF WEAK RADIO-SOURCES FROM THE RA TAN-600 KHOLOD DEEP SURVEY

A multi-frequency deep survey of a band of sky with the declination of the source SS433 (delta similar or equal to 5 degrees +/- 20') was ma de as part of the ''Kholod'' program on the RATAN-600 in 1987-1988. Th e right ascension intervals covered by the survey are 0(h) < alpha < 1 4(h) and 18(h) < alpha < 24(h). The spectral properties of 400 sources from the RC catalog were determined for the first time using only RAT AN-600 data. The maximum in the flux density distribution for these so urces at the central wavelength, 7.6 cm, occurs at similar to 30 mJy. The lower flux limits for the sample at wavelengths 3.9, 7.6, 13.0, an d 31.0 cm are 16, 9, 37, and 61 mJy, respectively. These observations provide the first flux estimates at 13.0 cm and 31.0 cm for 90% of the sources. Spectra were measured for the first time for 112 sources (28 %), and were revised for 90 sources (23%). The maximum in the spectral index distribution for the entire sample in the interval from 7.6-31. 0 cm occurs at alpha = -0.86 +/- 0.04 (S-nu similar to nu(alpha)). The spectra of some 30 of the sample sources (5%) are peaked at roughly 1 GHz, and about 40 spectra (10%) have low-frequency breaks. Roughly 70 sources (19%) have flat spectra (alpha > -0.5), and 64 have very stee p spectra (alpha < -1.1). A comparison of the types of spectra observe d in these weak sources and in a sample of compact steep-spectrum (CSS ) sources suggests that many of the survey sources may be CSS sources.