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

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 10(38.8-40.6) erg/s, with the average value of 10(39.7) erg/s. The data confirm the deficit of extended radio emission: the average value of the core-dominance parameter (log R approximate to -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 L-j/L-Edd = (0.52 +/- 0.15) log 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.

Automated summary

This paper presents observation results of 33 FR0 radio galaxies in the local universe, showing that they dominate compact radio sources and have flat, complex spectra with high opacity and multiple components contributing to the total spectrum. Additionally, a statistically significant correlation was found between parsec scale jet power and bolometric luminosity of the accretion disk. New candidates for sources with spectral peaks in the GHz range were identified, and 44% of objects exhibited peaked-shaped spectral profiles.