J/A+A/712/A182ivo://CDS.VizieR/J/A+A/712/A182CDSEuclid Coll.Laloux B.Bongiorno A.Salvato M.Allevato V.Mezcua M.,Roster W.Matamoro Zatarain T.Paltani S.Shirley R.Tarsitano F.,Saulder C.Fotopoulou S.Andonie C.Buchner J.La Franca F.Le Brun V.,Ricci F.Scott D.Shankar F.Siudek M.Sorce J.G.Spinoglio L.,Toba Y.Viitanen A.Wang L.Zamorani G.Andreon S.Auricchio N.,Baccigalupi C.Baldi M.Balestra A.Bardelli S.Battaglia P.,Biviano A.Branchini E.Brescia M.Camera S.Canas-Herrera G.,Capobianco V.Carbone C.Carretero J.Casas S.Castellano M.,Castignani G.Cavuoti S.Chambers K.C.Cimatti A.Colodro-Conde C.,Congedo G.Conselice C.J.Conversi L.Copin Y.Costille A.Courbin F.,Courtois H.M.Cropper M.Da Silva A.Degaudenzi H.De Lucia G.Dole H.,Dubath F.Duncan C.A.J.Dupac X.Escoffier S.Fabricius M.Farina M.,Farinelli R.Ferriol S.Finelli F.Fosalba P.Fourmanoit N.Frailis M.,Franceschi E.Fumana M.Galeotta S.George K.Gillis B.Giocoli C.,Gracia-Carpio J.Grazian A.Grupp F.Gwyn S.Haugan S.V.H.Hoekstra H.,Holmes W.Hormuth F.Hornstrup A.Jahnke K.Jhabvala M.Joachimi B.,Kermiche S.Kiessling A.Kubik B.Kuemmel M.Kunz M.Kurki-Suonio H.,Le Brun A.M.C.Ligori S.Lilje P.B.Lindholm V.Lloro I.Mainetti G.,Maino D.Maiorano E.Mansutti O.Marcin S.Marggraf O.Martinelli M.,Martinet N.Marulli F.Massey R.J.Medinaceli E.Mei S.Mellier Y.,Meneghetti M.Merlin E.Meylan G.Mora A.Moresco M.Moscardini L.,Nakajima R.Neissner C.Nichol R.C.Niemi S.-M.Padilla C.Pasian F.,Pedersen K.Percival W.J.Pettorino V.Pires S.Polenta G.Poncet M.,Popa L.A.Pozzetti L.Racca G.D.Raison F.Renzi A.Rhodes J.,Riccio G.Romelli E.Roncarelli M.Saglia R.Sakr Z.Sapone D.,Sartoris B.Schneider P.Schrabback T.Scodeggio M.Secroun A.,Seidel G.Serrano S.Sihvola E.Simon P.Sirignano C.Sirri G.,Steinwagner J.Tallada-Crespi P.Taylor A.N.Tereno I.Tessore N.,Toft S.Toledo-Moreo R.Torradeflot F.Tutusaus I.Valenziano L.,Valiviita J.Vassallo T.Veropalumbo A.Wang Y.Weller J.Zacchei A.,Zucca E.Ballardini M.Bolzonella M.Bozzo E.Burigana C.Cabanac R.,Calabrese M.Cappi A.Castro T.Escartin Vigo J.A.Gabarra L.,Garcia-Bellido J.Maoli R.Martin-Fleitas J.Maturi M.Mauri N.,Metcalf R.B.Pezzotta A.Poentinen M.Porciani C.Risso I.Scottez V.,Sereno M.Tenti M.Viel M.Wiesmann M.Akrami Y.Andika I.T.,Angora G.Anselmi S.Archidiacono M.Atrio-Barandela F.Bazzanini L.,Bertacca D.Bethermin M.Bisigello L.Blanchard A.Blot L.Bonici M.,Brown M.L.Bruton S.Calabro A.Camacho Quevedo B.Caro F.,Carvalho C.S.Cogato F.Conseil S.Cooray A.R.Davini S.De Paolis F.,Desprez G.Diaz-Sanchez A.Di Domizio S.Diego J.M.Elkhashab M.Y.,Enia A.Fang Y.Finoguenov A.Fontanot F.Franco A.Gasparetto T.,Gaztanaga E.Giacomini F.Gianotti F.Gozaliasl G.Guidi M.,Gutierrez C.M.Hall A.Hernandez-Monteagudo C.Hildebrandt H.Hjorth J.,Hunt L.K.Kajava J.J.E.Kang Y.Kansal V.Karagiannis D.Kiiveri K.,Kim J.Kirkpatrick C.C.Kruk S.Lattanzi M.Legrand L.Lepori F.,Leroy G.Lesci G.F.Lesgourgues J.Leuzzi L.Liaudat T.I.Liu S.J.,Lopez Lopez X.Macias-Perez J.Magliocchetti M.Magnier E.A.Mancini C.,Manjon-Garcia A.Mannucci F.Martins C.J.A.P.Maurin L.Miluzio M.,Monaco P.Montoro A.Moretti C.Morgante G.Murray C.Nadathur S.,Naidoo K.Natoli P.Navarro-Alsina A.Nesseris S.Paoletti D.,Passalacqua F.Paterson K.Pisani A.Potter D.Pratt G.W.Quai S.,Radovich M.Rodighiero G.Rojas K.Sacquegna S.Sahlen M.Sanders D.B.,Sarpa E.Schneider A.Sciotti D.Sellentin E.Smith L.C.Tanidis K.,Tao C.Testera G.Teyssier R.Tosi S.Troja A.Tucci M.Venhola A.,Vergani D.Verza G.Vielzeuf P.Vinciguerra S.Walton N.A.2026-08-18T08:03:15Z2026-08-18T08:44:51ZCDS support team

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

cds-question@unistra.frsurveysactive-galactic-nucleiredshiftedvisible-astronomyinfrared-astronomyThe Euclid Quick Data Release (Q1) is a powerful dataset to study active galactic nuclei (AGN) and their host galaxies. Deriving their physical properties through multi-component spectral energy distribution (SED) fitting is a challenging task for AGN, but it is greatly aided by the Euclid near-infrared photometry. Here we present a new method of quantifying the reliability of SED-derived parameters, such as AGN bolometric and monochromatic luminosities, host's stellar mass (M*), star-formation rate (SFR), and specific star-formation rate (sSFR), by using mock SEDs of AGN built by combining observed SEDs of QSOs and galaxies. We applied this methodology to the ~1 million Q1 AGN candidates, constructing a catalogue of AGN and host galaxy properties, alongside their respective reliability values. With a reliability threshold at 0.5, we find 88% of sources to have robust stellar masses and 76% to have reliable AGN luminosities. Moreover, through SED fitting we also measured the AGN fraction (fAGN) of the total mid-infrared flux and we used its lower-limit to select AGN. A f_AGN,ow_>0.075 threshold yields 85% completeness and purity. Comparable to colour-colour AGN selections, this method has the advantage of being less affected by redshift evolution and exploring fainter magnitudes. Additionally, by comparing the AGN and host galaxy parameters across different identification methods, we find that the probed range in stellar mass and AGN luminosity can be quite different. This highlights the importance of combining different approaches and accounting for their selection biases when studying AGN and their role in galaxy evolution. Finally, for the X-ray detected sample, we present the X-ray to mid-IR luminosity relation, and the correlation between stellar mass and bolometric luminosity as a function of redshift, in good agreement with previous results.2026A&A...712A.182Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/712/A182CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/234/23 : The WISE AGN candidates catalogs (Assef+, 2018)J/ApJ/796/60 : ECDFS galaxies photometric redshifts + counterparts (Hsu+,2014)J/A+A/711/A16 : X-ray point-like sources of Euclid (Q1) (Euclid Coll.+, 2026)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/712/A182https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/712/A182http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/712/A182https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/712/A182https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/712/A182http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/712/A182GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/712/A182/catalog (Accretion properties of X-ray AGN)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/712/A182/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/712/A182/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/712/A182/catalog?GETtext/xml+votable180.050000true267.993683998054665.96490905531610.005555555555555556Cone search capability for table J/A+A/712/A182/zphpdf (zphot PDF)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/712/A182/zphpdf?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/712/A182/zphpdf?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/712/A182/zphpdf?GETtext/xml+votable180.050000true267.3405259532667.271643127890.0055555555555555564/2145 5/2557 2559 2901 2903 3839 4010-4011 8506-8507 8579 8585 8592 8982-8983 8989 9032 6/10233 10235 11601 11603 11609 11611 15343 15351 15353-15355 16034-16035 16038-16039 16056 16058 33979 33981-33983 34307 34309-34311 34313-34315 34336-34337 34339 34352-34353 34372 34374 34376-34377 35923 35926-35927 35952-35953 35955 35964-35965 36098 36104 36106-36107https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/712/A182?format=asciiOpticalInfrareddefaultJ/A+A/712/A182/catalogAccretion properties of X-ray AGNrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDEuclid ID (id)meta.id;meta.mainRAJ2000Right ascension (J2000) of the Euclid source (right_ascension_euclid)degpos.eq.ra;meta.mainindexedE_Mstar? Stellar mass estimate 1-sigma upper uncertainty (Mstar_err_sup)solMassstat.error;stat.maxdoublenullableSFR? Star Formation Rate estimate (SFR)solMass/yrphys.SFRdoublenullablee_SFR[]? Star Formation Rate estimate 1-sigma lower uncertainty (SFR_err_inf)solMass/yrstat.error;phys.SFRdoublenullableE_SFR? Star Formation Rate estimate 1-sigma upper uncertainty (SFR_err_sup)solMass/yrstat.error;stat.maxdoublenullablesSFR? Specific Star Formation Rate estimate (sSFR)meta.iddoublenullableExtReGALFlagIf True, the source is located outside the interpolation region used during the reliability function construction, i.e. the reliability value should be taken with a grain of salt for inactive galaxy candidates (Sect 4.4)meta.codecharRelMstarStellar mass reliability for AGN candidates (reliability_Mstar)meta.code.qualdoubleRelMstarGALStellar mass reliability for inactive galaxy candidates (reliability_Mstar_GAL)meta.code.qualdoublee_RelMstar[]? Stellar mass lower uncertainty to reach at least 68% reliability (Sect 4.6.1) (realistic_Mstar_err_inf)stat.errordoublenullablee_RelMstarGAL[]? Stellar mass lower uncertainty to reach at least 68% reliability for inactive galaxy candidates (Sect 4.6.1) (realistic_Mstar_err_inf_GAL)stat.errordoublenullableE_RelMstar? Stellar mass upper uncertainty to reach at least 68% reliability (Sect 4.6.1) (realistic_Mstar_err_sup)stat.error;stat.maxdoublenullableE_RelMstarGAL? Stellar mass upper uncertainty to reach at least 68% reliability for inactive galaxy candidates (Sect 4.6.1) (realistic_Mstar_err_sup_GAL)stat.error;stat.maxdoublenullableRelSFRSFR reliability for AGN (reliability_SFR)meta.code.qualdoubleDEJ2000Declination (J2000) of the Euclid source (declination_euclid)degpos.eq.dec;meta.mainindexedzbest? Best redshift estimate, equal to best_zspec if available (best_z)src.redshift;pos.heliocentricdoublenullablezspbest? Best spectroscopic redshift (see confidence order from paper) (best_zspec)src.redshift;pos.heliocentricdoublenullablezphbest? Best photometric redshift (see confidence order from paper ) (best_zphot)src.redshift.photdoublenullablezph? Photometric redshift computed in this work (zphot_this_work)src.redshiftdoublenullableGoodFlagsAbsence of photometric flags (Matamoro et al., 2025, in prep.) (good_flags)meta.codecharE(B-V)galMilky-Way E(B-V) attenuation (gal_ebv_ebv)magphot.color.excessdoublemumax-mag? If below -2.6, the source is considered point-like (Matamoro et al., 2025, in prep.) (mumax_minus_mag_euclid)mag.arcsec**-2phot.mag.sbdoublenullablen_mumax-mag[I] I for Infinitymeta.notecharVISmag? Magnitude in the VIS band (mag_VIS)magphot.mag;em.optdoublenullableSampleAThe source belongs to sample A (has spectroscopic redshift) (Sample_A)meta.codecharSampleBThe source belongs to sample B (is an X-ray AGN candidates) (Sample_B) (1)meta.codecharSampleCThe source belongs to sample C (is an AGN candidate) (Sample_C)meta.codecharStarCandEFlag of star candidates (star_candidate_euclid)meta.codecharb24AEBisigello et al. (2024A&A...691A...1E) AGN selection A (bisigello24_a_euclid)meta.codecharb24BEBisigello et al. (2024A&A...691A...1E) AGN selection B (bisigello24_b_euclid)meta.codecharJHVISYEEuclid-based color-color selection from Matamoro et al., 2025, in prep. (jhvisy_euclid)meta.codecharVISHGZEEuclid-based color-color selection from Matamoro et al., 2025, in prep. (vishgz_euclid)meta.codecharA18C75AC75 mid-infrared AGN selection from Assef et al., 2018ApJS..234...23A, Cat. J/ApJS/234/23 (assef18_c75_allwise)meta.codecharA18R90AR90 mid-infrared AGN selection from Assef et al., 2018ApJS..234...23A, Cat. J/ApJS/234/23 (assef18_r90_allwise)meta.codecharQSO-PRFRandom forest AGN selection (Tucci et al., 2025, in prep.) (qso_PRF)meta.codecharQSO-QUAIAQSO flag by QUAIA (qso_quaia)meta.codecharQSO-GDR3QSO flag from GAIA DR3 (qso_gdr3)meta.codecharQSO-DESIQSO flag from DESI (qso_desi)meta.codecharisAGNbroadBroad-line AGN from DESI DR1 (is_agn_broad)meta.codecharisAGNnarrowNarrow-line AGN from DESI DR1 (is_agn_narrow)meta.codecharredChi2? Reduced chi-square value from the SED fitting (reduced_Chi2)stat.fit.chi2doublenullablez? Redshift value (redshift)src.redshiftdoublenullablee_z[]? Redshift value 1-sigma lower uncertainty (redshift_err_inf)stat.error;src.redshiftdoublenullableE_z? Redshift value 1-sigma upper uncertainty (redshift_err_sup)stat.error;stat.maxdoublenullableMstar? Stellar mass estimate (Mstar)solMassphys.massdoublenullablee_Mstar[]? Stellar mass estimate 1-sigma lower uncertainty (Mstar_err_inf)solMassstat.errordoublenullablee_sSFR[]? Specific Star Formation Rate estimate 1-sigma lower uncertainty (sSFR_err_inf)stat.errordoublenullableE_sSFR? Specific Star Formation Rate estimate 1-sigma upper uncertainty (sSFR_err_sup)stat.error;stat.maxdoublenullableAge? Host age estimate (age)Gyrtime.agedoublenullablee_Age[]? Host age estimate 1-sigma lower uncertainty (age_err_inf)Gyrstat.error;time.agedoublenullableE_Age? Host age estimate 1-sigma upper uncertainty (age_err_sup)Gyrstat.error;stat.maxdoublenullablefAGN? AGN fraction (5-20um) estimate (fAGN)meta.numberdoublenullablee_fAGN[]? AGN fraction (5-20um) estimate 1-sigma lower uncertainty (fAGN_err_inf)stat.errordoublenullableE_fAGN? AGN fraction (5-20um) estimate 1-sigma upper uncertainty (fAGN_err_sup)stat.error;stat.maxdoublenullableLAGN? AGN bolometric luminosity estimate (LAGN)solLumphys.luminositydoublenullablee_LAGN[]? AGN bolometric luminosity estimate 1-sigma lower uncertainty (LAGN_err_inf)solLumstat.errordoublenullableE_LAGN? AGN bolometric luminosity estimate 1-sigma upper uncertainty (LAGN_err_sup)solLumstat.error;stat.maxdoublenullableL6um? 6-micron AGN luminosity estimate (L6um)phys.luminosity;em.IRdoublenullablee_L6um[]? 6-micron AGN luminosity estimate 1-sigma lower uncertainty (L6um_err_inf)stat.errordoublenullableE_L6um? 6-micron AGN luminosity estimate 1-sigma upper uncertainty (L6um_err_sup)stat.error;stat.maxdoublenullableL2500A? 2500{AA} AGN luminosity estimate (L2500A)phys.luminositydoublenullablee_L2500A[]? 2500{AA} AGN luminosity estimate 1-sigma lower uncertainty (L2500A_err_inf)stat.errordoublenullableE_L2500A? 2500{AA} AGN luminosity estimate 1-sigma upper uncertainty (L2500A_err_sup)stat.error;stat.maxdoublenullableInc? AGN viewing angle estimate (inclination)pos.posAngdoublenullablee_Inc[]? AGN viewing angle estimate 1-sigma lower uncertainty (inclination_err_inf)stat.errordoublenullableE_Inc? AGN viewing angle estimate 1-sigma upper uncertainty (inclination_err_sup)stat.error;stat.maxdoublenullableE(B-V)? E(B-V) attenuation estimate (E_BV)magphot.color.excessdoublenullablee_E(B-V)[]? E(B-V) attenuation estimate 1-sigma lower uncertainty (E_BV_err_inf)magstat.errordoublenullableE_E(B-V)? E(B-V) attenuation estimate 1-sigma upper uncertainty (E_BV_err_sup)magstat.error;stat.maxdoublenullableSEDAGNCandAGN-candidate flag from SED fitting (fAGN+fAGN_err_inf>0.075, sect 5.2) (SED_AGN_candidate)meta.codecharBandAvailMost similar combination of available photometric bands to selected corresponding reliability functions (band_availability)meta.codecharW34flagWISE3 or WISE4 have flux measurements with SNR>3 (W34_flag)meta.codecharRelLAGNReliability of the AGN bolometric luminosity (reliability_LAGN)meta.code.qualdoubleRelL6umReliability of the AGN luminosity at 6um (reliability_L6um)meta.code.qualdoubleRelL2500AReliability of the AGN luminosity at 2500{AA} (reliability_L2500A)meta.code.qualdoubleRelSFRGALSFR reliability for inactive galaxy candidates (reliability_SFR_GAL)meta.code.qualdoubleSFRcor? Bias-corrected SFR estimate for AGN candidates (Sect 4.6.2) (corrected_SFR)solMass/yrphys.SFRdoublenullablee_SFRcor[]? Bias-corrected SFR estimate lower uncertainty for AGN candidates (Sect 4.6.2) (corrected_SFR_err_inf)solMass/yrstat.errordoublenullableE_SFRcor? Bias-corrected SFR estimate upper uncertainty for AGN candidates (Sect 4.6.2) (corrected_SFR_err_sup)solMass/yrstat.error;stat.maxdoublenullableRelsSFRSpecific SFR reliability for AGN (reliability_sSFR)meta.code.qualdoubleRelsSFRGALSpecific SFR reliability for inactive galaxy candidates (reliability_sSFR_GAL)meta.code.qualdoubleFieldThe source is within Euclid Deep Field North (EDFN), South (EDFS), or Fornax (EDFF) (field)meta.id;obs.fieldcharExtRelFlagIf True, the source is located outside the interpolation region used during the reliability function construction, i.e. the reliability value should be taken with a grain of salt. (extrapolated_relia_flag)meta.codecharJ/A+A/712/A182/zphpdfzphot PDFFieldField (field)meta.id;obs.fieldcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDEuclid ID (id)meta.id;meta.mainRAJ2000Right ascension (J2000) Euclid (right_ascension_euclid)degpos.eq.ra;meta.mainindexedDEJ2000Declination (J2000) Euclid (declination_euclid)degpos.eq.dec;meta.mainindexedzbestBest redshift estimate (best_z)src.redshift;pos.heliocentricdoublezspbest? Best spectroscopic redshift(best_zspec)src.redshift;pos.heliocentricdoublenullablezphbestBest photometric redshift (best_zphot)src.redshift.photdoublezphPhotometric redshift computed in this work (zphot_this_work)src.redshiftdouble