Analysis of the update sample of USS objects and search of candidates to GPS sources in the RZF survey

A deep RATAN-600 Zenith Field (RZF) survey at wavelength ${\lambda}$ = 7.6 cm on the declination of the 3C84 radio source. In the center of the survey region, 448 objects were detected, and 73 of them have ultra-steep spectra (USS), which are the main indicator for finding possible candidates for distant galaxies. Optical identifications for 31 of the USS objects were made using the SDSS surveys have been used. It turns out that 23 objects are galaxies and 8 are star-forming objects. Photometric redshifts ($z_{\rm ph}$) and radio luminosities at 3.9 and 1.4 GHz ($L_{3.9}$ and $L_{1.4}$) are determined for 31 objects with spectral indices $\alpha < -1.1$, $S_{\rm \nu} \sim \nu^\alpha$ for objects with published photometric data. In the sample of USS objects, 15 galaxies have $z_{\rm ph}< 0.5$, and 8 of them have relatively high $L_{1.4} > 10^{26}$ W/Hz of type FR II. Seven galaxies at $z_{\rm ph} > 0.5$ are also of type FR II. Five sources are of intermediate type FR I-FR II. Only three radio galaxies at $z_{\rm ph}<0.5$ turned out to be a rare nearby galaxy with relatively low $L_{1.4}<10^{25}$ W/Hz (FR I). These radio sources are either located in the dense intergalactic medium of rich clusters or are confined within their host galaxies. Almost all of these sources can be observed with the SAO 6-m telescope. Galaxies with $L_{1.4} > 10^{26}$ W/Hz (FR II) have magnitudes $18<m_{\rm r}<23$. The search for Gigahertz Peaked-spectrum (GPS) candidates in the RZF survey was performed, and 29 objects were classified as GPS candidates. The most sensitive radio and optical catalogs, a new blazar candidate catalog, Blazar Radio and Optical Survey (BROS) were used. We propose 7 new candidates for GPS sources and 5 new Megahertz Peaked-spectrum (MPS) sources based on their spectral shape and variability characteristics.