Radio Properties of FR0 Galaxies According to Multifrequency Measurements with RATAN-600

Mikhailov, A. G. , Sotnikova Yu. V.

Recent studies have shown that among the population of radio-loud active galactic nuclei in the local U-niverse, they numerically dominate compact radio sources of the FR0 class. In this paper, we present ob-servation results of a sample of 33 FR0 radio galaxies with RATAN-600 in the first half of 2020. For the first time, quasi-simultaneous spectra of this class objects have been measured in the frequency range as wide as 2.25-22.3 GHz. Radio luminosity of the sampled objects at the frequency 4.7 GHz varies within 1${\mathrm{0^}}^{38.8-40.6}$ erg/s, with the average value of ${\mathrm{10^}}^{39.7}$ erg/s. The data confirm the deficit of extended radio emission: the average value of the core-dominance parameter ($\log R\approx -0.10$) substantially exceeds the values typical for FRI galaxies. Quasi-simultaneous spectra are flat, while in the range 4.7-8.2 GHz, the average spectral index is close to zero. The spectra of 44 percent of objects which have more than three quasi-simultaneous points have peaked-shaped profiles. Using additional data of catalogs allowed us to identify three new candidates for the sources with the maximum of the spectrum in the GHz range. A statistically significant correlation was found between the parsec scale jet power and the bolometric luminosity of the accretion disk: $\log\tfrac{{{{L}j}}}{{{{L}_{{{Edd}}}}}} = (0.52 ± 0.15)\log\tfrac{{{{L}_{{{bol}}}}}}{{{{L}_{{{Edd}}}}}} - (0.69 ± 0.51)$. In general, the spectra of the studied objects are flat and have a complex structure, which indicates a high opacity in the radio range and the contribution of several components to the total spectrum. Original →