Radio Properties of High-Redshift Galaxies at
Study of high-redshift radio galaxies (HzRGs) can shed light on the active galactic nuclei (AGNs) evolution in massive elliptical galaxies. The vast majority of observed high-redshift AGNs are quasars, and there are very few radio galaxies at redshifts . We present the radio properties of 173 source...
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Published in | Astrophysical bulletin Vol. 78; no. 4; pp. 443 - 463 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Moscow
Pleiades Publishing
2023
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Study of high-redshift radio galaxies (HzRGs) can shed light on the active galactic nuclei (AGNs) evolution in massive elliptical galaxies. The vast majority of observed high-redshift AGNs are quasars, and there are very few radio galaxies at redshifts
. We present the radio properties of 173 sources optically identified with radio galaxies at
with flux densities
mJy. Literature data were collected for compilation of broadband radio spectra, estimation of radio variability, radio luminosity, and radio loudness. Almost 60
of the galaxies have steep or ultra-steep radio spectra; 22
have flat, inverted, upturn, and complex spectral shapes, and 18
have peaked spectra (PS). The majority of the PS sources in the sample (20/31) are megahertz-peaked spectrum source candidates, i.e. possibly very young and compact radio galaxies. The median values of the variability indices at 11 and 5 GHz are
and
, which generally indicates a weak or moderate character of the long-term variability of the studied galaxies. The typical radio luminosity and radio loudness are
erg s
and
respectively. We have found less prominent features of the bright compact radio cores in our sample compared to high-redshift quasars at
. The variety of the obtained radio properties shows the different conditions for the formation of radio emission sources in galaxies. |
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ISSN: | 1990-3413 1990-3421 |
DOI: | 10.1134/S1990341323700190 |