Connecting MeerKAT radio continuum properties to GAMA optical emission-line and WISE mid-infrared activity

Abstract

The identification of AGN in large surveys has been hampered by seemingly discordant classifications arising from differing diagnostic methods, usually tracing distinct processes specific to a particular wavelength regime. However, as shown in Yao et al. (2020), the combination of optical emission line measurements and mid-infrared photometry can be used to optimise the discrimination capability between AGN and star formation activity. In this paper we test our new classification scheme by combining the existing GAMA-WISE data with high-quality MeerKAT radio continuum data covering 8 deg${}^2$ of the GAMA G23 region. Using this sample of 1 841 galaxies (z < 0.25), we investigate the total infrared (derived from 12$\mu$m) to radio luminosity ratio, q(TIR), and its relationship to optical-infrared AGN and star-forming (SF) classifications. We find that while q(TIR) is efficient at detecting AGN activity in massive galaxies generally appearing quiescent in the infrared, it becomes less reliable for cases where the emission from star formation in the host galaxy is dominant. However, we find that the q(TIR) can identify up to 70 % more AGNs not discernible at optical and/or infrared wavelengths. The median q(TIR) of our SF sample is 2.57 $\pm$ 0.23 consistent with previous local universe estimates.

References in corpus (29)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• The Host Galaxies and Classification of Active Galactic Nuclei
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• Radio galaxies and feedback from AGN jets
• SoFiA: a flexible source finder for 3D spectral line data
• Galaxy And Mass Assembly (GAMA): the G02 field, Herschel-ATLAS target selection and Data Release 3
• Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey
• The far-infrared/radio correlation and radio spectral index of galaxies in the SFR-M* plane up to z 2
• On the two main classes of Active Galactic Nuclei
• The NuSTAR View of Nearby Compton-thick AGN: The Cases of NGC 424, NGC 1320 and IC 2560
• The WISE Extended Source Catalogue (WXSC) I: The 100 Largest Galaxies
• Galaxy and Mass Assembly (GAMA): Exploring the WISE Cosmic Web in G12
• Galaxy And Mass Assembly: The 1.4GHz SFR indicator, SFR-M* relation and predictions for ASKAP-GAMA
• Calibration of ultraviolet, mid-infrared and radio star formation rate indicators
• Galaxy And Mass Assembly (GAMA): Active Galactic Nuclei in Pairs of Galaxies
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: radio properties and the far-infrared/radio correlation
• The non-linear infrared-radio correlation of low-z galaxies: implications for redshift evolution, a new radio SFR recipe, and how to minimize selection bias
• Deep Extragalactic VIsible Legacy Survey (DEVILS): Identification of AGN through SED Fitting and the Evolution of the Bolometric AGN Luminosity Function
• The Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS): Survey design, data catalogue and GAMA/WiggleZ spectroscopy
• Recalibrating the Wide-field Infrared Survey Explorer (WISE) W4 Filter
• Radio Source Extraction with ProFound
• Galaxy and Mass Assembly (GAMA): Demonstrating the power of WISE in the study of Galaxy Groups to $z<0.1$
• Cosmic evolution of star-forming galaxies to $z\simeq 1.8$ in the faint low-frequency radio source population
• An extinction free AGN selection by 18-band SED fitting in mid-infrared in the AKARI NEP deep field
• AGN's UV and X-ray luminosities in clumpy accretion flows
• Galaxy and Mass Assembly (GAMA): A $\text{WISE}$ study of the activity of emission-line systems in G23
• PKS 2250$-$351: A Giant Radio Galaxy in Abell 3936
• ASKAP Commissioning Observations of the GAMA 23 Field
• The detection of a massive chain of dark HI clouds in the GAMA G23 Field

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• WISE2MBH: A scaling-based algorithm for probing supermassive black hole masses through WISE catalogues
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• Identifying Radio Active Galactic Nuclei with Machine Learning and Large-Area Surveys