J/A+A/708/A373ivo://CDS.VizieR/J/A+A/708/A373CDSLa Marca A.Margalef-Bentabol B.Wang L.Trager S.C.,Rodriguez-Gomez V.Martin G.2026-05-19T14:14:26Z2026-04-28T11:12:28ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiescatalogsredshiftedstellar-massesvisible-astronomyinfrared-astronomyGalaxy major mergers are a potential mechanism for triggering active galactic nuclei (AGN) activity, but their role remains debated, particularly beyond the local Universe. We aim to shed light on the merger-AGN connection at z=0.5-2, exploiting the multi-wavelength datasets and James Webb Space Telescope (JWST) observations in the COSMOS field. We construct a stellar mass-limited sample and identify AGN via mid-infrared (MIR) colours, X-ray detections, and spectral energy distribution (SED) fitting. We train convolutional neural networks to identify mergers with mock JWST observations. We create non-AGN and non-merger control samples matching the redshift, stellar mass, and star-formation rate distributions of the AGN and mergers. We find AGN to be moderately more frequent in mergers than in non-mergers, with excess ratios ranging from ~2.5 (X-ray AGN) to ~1.3 (MIR) and ~1.1-1.2 (SED AGN). Similarly, AGN galaxies show a higher merger fraction (f_merg_) than non-AGN controls. We then study f_merg_ as a function of relative and absolute AGN power, utilising the AGN fraction (f_AGN_) and accretion disc luminosity (L_disc_) parameters. We uncover a f_merg_-f_AGN_ relation with two regimes: f_merg_ stays roughly flat for less-dominant AGN (f_AGN_<0.8) but increases at f_AGN_>0.8 for the MIR and X-ray AGN, and more gently for SED AGN, where mergers appear to be the main triggering mechanism. Additionally, f_merg_ increases monotonically as a function of L_disc_, for all AGN types, reaching f_merg_>50% for the most luminous AGN (L_disc_>~10^46^erg/s). Overall, our results suggest that major mergers can trigger AGN out to the cosmic noon at z~2. Furthermore, the role of major mergers shows a clear dependence on AGN luminosity and remains the principal mechanism for fuelling the most powerful AGN.2026A&A...708A.373Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/A373CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/258/11 : The COSMOS2020 catalog (Weaver+, 2022)J/A+A/688/A20 : COSMOS2020-MIPS-PACS-SPIRE-SCUBA catalog (Wang+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/A373https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/708/A373http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/708/A373https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/708/A373https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/708/A373http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/708/A373GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/708/A373/catalog (COSMOS Web Master Catalogue z=0.5-2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A373/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A373/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A373/catalog?GETtext/xml+votable180.050000true150.05843723158942.54362309349110.0055555555555555566/27256 27258https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/708/A373?format=asciiOpticalInfrareddefaultJ/A+A/708/A373/catalogCOSMOS Web Master Catalogue z=0.5-2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIdFarmer id from COSMOS2020 catalog (id)meta.id;meta.mainintRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainindexedDEJ2000Declination (J2000) (DEC)degpos.eq.dec;meta.mainindexedzRedshift (z_summary)src.redshiftdoublef_z[1/3] Redshfit source (z_source) (1)meta.codeintMstarCIGALE stellar mass (bayes.stellar.m_star)solMassphys.massdoublee_MstarCIGALE stellar mass uncertainty (bayes.stellar.m_star_err)solMassstat.errordoubleSFRCIGALE star-formation rate (bayes.sfh.sfr)solMass/yrphys.SFRdoublee_SFRCIGALE star-formation rate uncertainty (bayes.sfh.sfr_err)solMass/yrstat.error;phys.SFRdoublefracAGNAGN fraction 3-30 micron (bayes.agn.fracAGN)phys.luminosity;arith.ratiodoublee_fracAGNAGN fraction uncertainty 3-30 micron (bayes.agn.fracAGN_err)stat.errordoubleAccPowerAGN accretion power (bayes.agn.accretion_power)Wphys.luminositydoublee_AccPowerAGN accretion power uncertainty (bayes.agn.accretion_power_err)Wstat.errordoubleDiskLumAGN disk luminosity (bayes.agn.disk_luminosity)Wphys.luminositydoublee_DiskLumAGN disk luminosity uncertainty (bayes.agn.disk_luminosity_err)Wstat.errordoubleAGNLumAGN luminosity (bayes.agn.luminosity)Wphys.luminositydoublee_AGNLumAGN luminosity uncertainty (bayes.agn.luminosity_err)Wstat.errordoublechi2chi square of best CIGALE fit (best.chi_square)stat.fit.chi2;meta.modelleddoublerchi2Reduced chi square of best CIGALE fit (best.reduced_chi_square)stat.fit.chi2doubledeltarchi2? Difference on reduced chi square with and without AGN (delta_reduced_chi2)stat.fit.chi2doublenullablerelrchi2? Relative difference on reduced chi square with and without AGN (relative_reduced_chi2_change)stat.fit.chi2doublenullableHAModelHorizon-AGN Model predicted score (HA Model)stat.fit.goodnessdoubleTNGModelIllustris-TNG Model predicted score (TNG Model)stat.fit.goodnessdoubleMergerClass[0/1]? Merger Classification adopted in the work (Merger Classification)meta.codeintnullable