AGN optical-infrared relation

Although the population of quasars evolved significantly in the past, the properties of quasars as physical objects are supposed to remain almost unchanged, which makes quasars promising candidates for cosmological tests. The X-UV luminosity relation in particular is widely used for this purpose. However, the potential of other spectral domains for this purpose remains open. The aim of the analysis we present is to test the parameter space in order to build a well behaving OPT-IR correlation that could serve as a cosmological probe. The main objective is to calibrate the OPT-IR luminosity relation for quasars, focusing on accurate estimations of dusty torus and accretion disk luminosities. We analyzed contaminations related to host galaxies, particularly from polar dust, the interstellar medium, and stellar emission that affect the optical and infrared. We used a sample of nearly 400 quasars with photometrical observations and spectroscopical redshift divided into four redshift bins (0.7-2.4). Full spectral energy distribution (SED) fitting was performed with the CIGALE code, and results were compared with simplified photometric luminosity estimates. The impact of non-active galactic nucleus components and the role of polar dust in the fitting process were assessed. We show that for sources with a disk luminosity above 10^45^[erg/s], the photometric estimates are consistent with SED-based values. While polar dust contributes marginally to luminosity, its presence significantly alters SED fitting, particularly the torus opening angle and cold dust properties. In the optical domain, stellar emission is the dominant contamination. In the infrared, disk emission and cold dust play major roles. We propose two empirical calibrations for the OPT-IR relation. We conclude that the optical band is dominated by the accretion disk component above 10^45^ or 10^46^[erg/s] depending on redshift, while IR luminosity is dominated by the dusty torus emission above 1.6x10^45^ or 2x10^46^[erg/s] depending on the redshift. In this high-luminosity regime, simplified photometric methods yield reliable disk and torus luminosity estimates.

Cone search capability for table J/A+A/708/A31/sample (Data sample)

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/708/A31
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/A31
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/A31
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/708/A31
Provenance
Creator Ralowski M.; Hryniewicz K.; Malek K.; Pollo A.; Risaliti G.
Publisher CDS
Publication Year 2026
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy