Determining the core radio luminosity function of radio AGNs via copula
| Autor: | Bin-Bin Zhang, Zunli Yuan, Jirong Mao, Jiancheng Wang, Diana M Worrall |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Active galactic nucleus
Radio galaxy Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Copula (probability theory) symbols.namesake Relativistic beaming 0103 physical sciences 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics luminosity function [galaxies] Physics Number density 010308 nuclear & particles physics Astronomy and Astrophysics Quasar Conditional probability distribution Astrophysics - Astrophysics of Galaxies galaxies [radio continuum] Lorentz factor Space and Planetary Science mass function Astrophysics of Galaxies (astro-ph.GA) active [galaxies] symbols |
| Zdroj: | Yuan, Z, Wang, J, Worrall, D M, Zhang, B-B & Mao, J 2018, ' Determining the Core Radio Luminosity Function of Radio AGNs via Copula ', Astrophysical Journal Supplement Series, vol. 239, no. 2, 33 . https://doi.org/10.3847/1538-4365/aaed3b |
| DOI: | 10.48550/arxiv.1810.12713 |
| Popis: | The radio luminosity functions (RLFs) of active galactic nuclei (AGNs) are traditionally measured based on total emission, which doesn't reflect the current activity of the central black hole. The increasing interest in compact radio cores of AGNs requires determination of the RLF based on core emission (i.e., core RLF). In this work we have established a large sample (totaling 1207) of radio-loud AGNs, mainly consisting of radio galaxies (RGs) and steep-spectrum radio quasars (SSRQs). Based on the sample, we explore the relationship between core luminosity ($L_c$) and total luminosity ($L_t$) via a powerful statistical tool called "Copula". The conditional probability distribution $p(\log L_{c} \mid \log L_{t})$ is obtained. We derive the core RLF as a convolution of $p(\log L_{c} \mid \log L_{t})$ with the total RLF which was determined by previous work. We relate the separate RG and SSRQ core RLFs via a relativistic beaming model and find that SSRQs have an average Lorentz factor of $\gamma=9.84_{-2.50}^{+3.61}$, and that most are seen within $8^{\circ} \lesssim \theta \lesssim 45^{\circ}$ of the jet axis. Compared with the total RLF which is mainly contributed by extended emission, the core RLF shows a very weak luminosity-dependent evolution, with the number density peaking around $z\thicksim 0.8$ for all luminosities. Differences between core and total RLFs can be explained in a framework involving a combination of density and luminosity evolutions where the cores have significantly weaker luminosity evolution than the extended emission. Comment: Accepted for publication in the ApJS |
| Databáze: | OpenAIRE |
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