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Cosmic evolution of radio-excess active galactic nuclei in quiescent and star-forming galaxies across 0 < z < 4

Wang, Yijun; Wang, Tao; Liu, Daizhong; Sargent, Mark T.; Gao, Fangyou; Alexander, David M.; Rujopakarn, Wiphu; Zhou, Luwenjia; Daddi, Emanuele; Xu, Ke; Kohno, Kotaro; Jin, Shuowen

Cosmic evolution of radio-excess active galactic nuclei in quiescent and star-forming galaxies across 0 < z < 4 Thumbnail


Yijun Wang

Tao Wang

Daizhong Liu

Mark T. Sargent

Fangyou Gao

Wiphu Rujopakarn

Luwenjia Zhou

Emanuele Daddi

Ke Xu

Kotaro Kohno

Shuowen Jin


Context. Radio-excess active galactic nuclei (radio-AGNs) are essential to our understanding of both the physics of black hole (BH) accretion and the interaction between BHs and host galaxies. Recent deep and wide radio continuum surveys have made it possible to study radio-AGNs down to lower luminosities and up to higher redshifts than previous studies, and are providing new insights into the abundance and physical origin of radio-AGNs.
Aims. Here we focus on the cosmic evolution, physical properties, and AGN-host galaxy connections of radio-AGNs selected from a total sample of ∼400 000 galaxies at 0 < z < 4 in the GOODS-N and COSMOS fields.
Methods. Combining the deep radio continuum data with multi-band, de-blended far-infrared, and submillimeter data, we were able to identify 983 radio-AGNs out of the entire galaxy sample through radio excess relative to the far-infrared–radio relation.
Results. We studied the cosmic evolution of 1.4 GHz radio luminosity functions (RLFs) for both star-forming galaxies (SFGs) and radio-AGNs, which can be well described by a pure luminosity evolution of L⋆ ∝ (1 + z)−0.34 × z + 3.57 and a pure density evolution of Φ⋆ ∝ (1 + z)−0.77 × z + 2.69, respectively. We derived the turnover luminosity, above which the number density of radio-AGNs surpasses that of SFGs. We show that this crossover luminosity increases with increasing redshifts, from 1022.9 W Hz−1 at z ∼ 0 to 1025.2 W Hz−1 at z ∼ 4. At the full redshift range of 0 < z < 4, we further derive the probability (pradio) of SFGs and quiescent galaxies (QGs) hosting a radio-AGN, as a function of stellar mass (M⋆), radio luminosity (LR), and redshift (z), which yields pradio ∝ (1+z)3.08 M⋆1.06 LR−0.77 for SFGs, and pradio ∝ (1+z)2.47 M⋆1.41 LR−0.60 for QGs, respectively.
Conclusions. The quantitative relation for the probabilities of galaxies hosting a radio-AGN indicates that radio-AGNs in QGs prefer to reside in more massive galaxies with higher LR than those in SFGs. The fraction of radio-AGN increases toward higher redshift in both SFGs and QGs, with a more rapid increase in SFGs.

Journal Article Type Article
Acceptance Date Feb 9, 2024
Online Publication Date May 8, 2024
Publication Date 2024-05
Deposit Date Jul 1, 2024
Publicly Available Date Jul 1, 2024
Journal Astronomy & Astrophysics
Print ISSN 0004-6361
Electronic ISSN 1432-0746
Publisher EDP Sciences
Peer Reviewed Peer Reviewed
Volume 685
Article Number A79
Public URL


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