J/MNRAS/516/2736ivo://CDS.VizieR/J/MNRAS/516/2736CDSBurke C.J.Liu X.Shen Y.Phadke K.A.Yang Q.Hartley W.G.,Harrison I.Palmese A.Guo H.Zhang K.Kron R.Turner D.J.,Giles P.A.Lidman C.Chen Y.-C.Gruendl R.A.Choi A.Amon A.,Sheldon E.Aguena M.Allam S.Andrade-Oliveira F.Bacon D.Bertin E.,Brooks D.Carnero Rosell A.Carrasco Kind M.Carretero J.Conselice C.,Costanzi M.Da Costa L.N.Pereira M.E.S.Davis T.M.De Vicente J.,Desai S.Diehl H.T.Everett S.Ferrero I.Flaugher B.,Garcia-Bellido J.Gaztanaga E.Gruen D.Gschwend J.Gutierrez G.,Hinton S.R.Hollowood D.L.Honscheid K.Hoyle B.James D.J.Kuehn K.,Maia M.A.G.Marshall J.L.Menanteau F.Miquel R.Morgan R.,Paz-Chinchon F.Pieres A.Plazas Malagon A.A.Reil K.Romer A.K.,Sanchez E.Schubnell M.Serrano S.Sevilla-Noarbe I.Smith M.,Suchyta E.Tarle G.Thomas D.To C.Varga T.N.Wilkinson R.D.,(The DES Collaboration)2025-10-08T09:15:09Z2025-10-06T15:44:03ZCDS support team

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

cds-question@unistra.frblack-holesgalaxiesdwarf-galaxiesactive-galactic-nucleiastrometryphotometryvisible-astronomystellar-massesredshiftedspectroscopyinfrared-astronomyx-ray-sourcesWe present a sample of 706, z < 1.5 active galactic nuclei (AGNs) selected from optical photometric variability in three of the Dark Energy Survey (DES) deep fields (E2, C3, and X3) over an area of 4.64 deg^2^. We construct light curves using difference imaging aperture photometry for resolved sources and non- difference imaging PSF photometry for unresolved sources, respectively, and characterize the variability significance. Our DES light curves have a mean cadence of 7 d, a 6-yr baseline, and a single-epoch imaging depth of up to g ~ 24.5. Using spectral energy distribution (SED) fitting, we find 26 out of total 706 variable galaxies are consistent with dwarf galaxies with a reliable stellar mass estimate (M* < 10^9.5^M_{Sun}_; median photometric redshift of 0.9). We were able to constrain rapid characteristic variability time-scales (~ weeks) using the DES light curves in 15 dwarf AGN candidates (a subset of our variable AGN candidates) at a median photometric redshift of 0.4. This rapid variability is consistent with their low black hole (BH) masses. We confirm the low-mass AGN nature of one source with a high S/N optical spectrum. We publish our catalogue, optical light curves, and supplementary data, such as X-ray properties and optical spectra, when available. We measure a variable AGN fraction versus stellar mass and compare to results from a forward model. This work demonstrates the feasibility of optical variability to identify AGNs with lower BH masses in deep fields, which may be more 'pristine' analogues of supermassive BH seeds.2022MNRAS.516.2736Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/516/2736CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/334 : VISTA Deep Extragalactic Observations (VIDEO)II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)IX/57 : The Chandra Source Catalog (CSC), Release 2.0J/MNRAS/487/4285 : Variable AGN candidates catalog (Pouliasis+, 2019)J/MNRAS/510/687 : Viewing angle in AGN SED models (Ramos Padilla+, 2022)J/A+A/474/473 : XMM-LSS survey: AGN classifications (Garcet+, 2007)J/A+A/544/A156 : UltraVISTA Catalogue Release DR1 (McCracken+, 2012)J/A+A/622/A103 : Python Code Investigating GALaxy Emission (Boquien+,2019)J/A+A/634/A50 : Optically variable AGN in the VST/CDF-S (Poulain+, 2020)J/A+A/627/A33 : Optically variable AGN in COSMOS field (De Cicco+, 2019)J/A+A/574/A112 : COSMOS field variability-selected AGN nucleiJ/A+A/488/73 : Variability-selected AGN in Chandra DFS (Trevese+, 2008)J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)J/ApJ/775/116 : z<0.06 active black hole galaxies from SDSS-DR8J/ApJ/813/82 : z<0.06 broad-line AGN emission-line measuresJ/ApJ/922/155 : [FeX]{lambda}6374 em. in SDSS dwarf galaxiesJ/ApJ/888/36 : SDSS/FIRST dwarf galaxies with VLA high res. obs.J/ApJ/748/124 : AGN X-ray variability in the 4Ms catalog (Young+, 2012)J/ApJ/830/51 : FourStar galaxy evolution survey (ZFOURGE)J/ApJ/896/10 : NSA low-mass galaxies with long-term PTF obs.J/ApJ/894/24 : Optical variability of AGN from the HSC SSP surveyJ/ApJ/854/160 : SDSS and DES long-term extreme variability QSOsJ/ApJ/805/96 : SDSS-RM project: velocity dispersions of QSOsJ/ApJ/757/83 : The Blanco Cosmology Survey (BCS) (Desai+, 2012)J/ApJ/789/147 : Star formation histories of LG dwarf galaxiesJ/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxiesJ/ApJ/772/26 : AGN with WISE. II. The NDWFS Bootes field (Assef+, 2013)J/ApJS/228/2 : Chandra Deep Field-South survey: 7Ms sources (Luo+, 2017)J/ApJS/228/9 : Physical parameters of ~300000 SDSS-DR12 QSOsJ/ApJS/201/30 : The Chandra COSMOS survey. III. (Civano+, 2012)J/ApJS/241/34 : The SDSS Reverberation Mapping (SDSS-RM) projectJ/AJ/153/107 : Australian Dark Energy Survey (OzDES) quasar catalogJ/AJ/154/269 : A new photo-z method for quasars in Stripe 82J/other/Sci/373.789 : optical variability of AGNs (Burke+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/516/2736https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/516/2736http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/516/2736https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/516/2736https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/516/2736http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/516/2736GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/516/2736/table2 (Variability-selected AGN candidates regardless of stellar mass or variability properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/516/2736/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/516/2736/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/516/2736/table2?GETtext/xml+votable180.050000true52.1408-27.18230.005555555555555556Cone search capability for table J/MNRAS/516/2736/table3 (Catalogue of 15 variable AGN candidates with rapid variability log({tau}_DRW_)<1.5)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/516/2736/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/516/2736/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/516/2736/table3?GETtext/xml+votable180.050000true52.961-28.48630.0055555555555555565/8847 6/17683 17686 17689 17691-17693 35382-35383 35385 35387 35473 35476 35931-35932 35934-35935 35953 35956-35957https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/516/2736?format=asciiX-rayOpticalInfrareddefaultJ/MNRAS/516/2736/table2Variability-selected AGN candidates regardless of stellar mass or variability propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMoreLink to table3meta.ref.urlcharNameVariable AGB name candidates (Name)meta.id;meta.maincharprimaryDESDisplay The Dark Energy Survey DR2meta.ref.urlcharRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (Dec)degpos.eq.dec;meta.maingmagMedian DES g magnitude in AB system (g)magphot.mag;em.opt.BfloatSNRSignal to noise ratio as described by the estimator in equation 9 of the section 2.5.1 (SNR)stat.snr;meta.modelled;arithfloatsigLBLjung-Box test significance as described in section 2.5.3 AGN-like variability ({sigma}_LB_)stat.fit.goodness;meta.modelledfloatlog(F2-7)? Chandra hard X-ray F2-7_keV_ (logF2-7_keV_/ergs^-1^cm^-2^)log(0.001W.m**-2)phot.flux;em.X-ray.mediumfloatnullableField[SN-C3/SN-E2/SN-X3] DES deep fields as SN-C3 for 300 cases, SN-E2 for 234 cases and SN-X3 for 172 cases (Field)obs.fieldcharlog(M*)Stellar mass estimate with CIGALE code as described in section 2.7 Stellar mass estimation (logM*/M_{Sun}_)log(solMass)phys.mass;meta.modelledfloate_log(M*)Mean uncertainty of log (M*) (errlogM*/M_{Sun}_)log(solMass)stat.errorfloatDChi2Difference between reduced {Chi}^2^ values like {chi}^2^_fAGN=1_ - {Chi}^2^ in section 2.7 ({Delta}{Chi}^2^_{nu}_)stat.fit.chi2;meta.modelledfloatlog(Tau)Characteristic damping variability time-scale term {tau}_DRW_ as described in section 2.8 (log{tau}_DRW_/days)log(d)time.scale;phys.atmol.damping;stat.paramfloate_log(Tau)Mean uncertainty of log (TauDRW) (errlog{tau}_DRW_/days)log(d)stat.errorfloatzphPhotometric redshift z_ph_ with method of Yang et al. 2017AJ....154..269Y, Cat. J/AJ/154/269 as section 2.6 (z_ph_)src.redshift;meta.modelledfloatE_zph? Upper uncertainty of zph (Errz_ph_)stat.error;stat.maxfloatnullablee_zphLower uncertainty of zph (errz_ph_)stat.errorfloatzsp? Spectroscopic redshift z_sp_ (z_sp_)src.redshiftfloatnullabler_zspLiterature reference of zsp (z_sp_source) (1)meta.ref;pos.framecharW1-W2? WISE W1-W2 colour (W1-W2)magphot.color;em.IR.3-4um;em.IR.4-8umfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/MNRAS/516/2736/table3Catalogue of 15 variable AGN candidates with rapid variability log({tau}_DRW_)<1.5recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameVariable AGB name candidates (Name)meta.id;meta.maincharRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (Dec)degpos.eq.dec;meta.maingmagMedian DES g magnitude in AB system (g)magphot.mag;em.opt.BfloatSNRSignal to noise ratio as described by the estimator in equation 9 of the section 2.5.1 (SNR)stat.snr;meta.modelled;arithfloatsigLBLjung-Box test significance as described in section 2.5.3 AGN-like variability ({sigma}_LB_)stat.fit.goodness;meta.modelledfloatlog(M*)Stellar mass estimate with CIGALE code as described in section 2.7 Stellar mass estimation (logM*/M_{Sun}_)log(solMass)phys.mass;meta.modelledfloate_log(M*)Mean uncertainty of log (M*) (errlogM*/M_{Sun}_)log(solMass)stat.errorfloatDChi2Difference between reduced {Chi}^2^ values like {chi}^2^_fAGN=1_ - {Chi}^2^ in section 2.7 ({Delta}{Chi}^2^_{nu}_)stat.fit.chi2;meta.modelledfloatlog(Tau)Characteristic damping variability time-scale term {tau}_DRW_ as described in section 2.8 (log{tau}_DRW_/days)log(d)time.scale;phys.atmol.damping;stat.paramfloate_log(Tau)Mean uncertainty of log (TauDRW) (errlog{tau}_DRW_/days)log(d)stat.errorfloatzphPhotometric redshift z_ph_ with method of Yang et al. 2017AJ....154..269Y, Cat. J/AJ/154/269 as section 2.6 (z_ph_)src.redshift;meta.modelledfloatE_zphUpper uncertainty of zph (Errz_ph_)stat.error;stat.maxfloate_zphLower uncertainty of zph (errz_ph_)stat.errorfloatzsp? Spectroscopic redshift z_sp_ (z_sp_)src.redshiftfloatnullabler_zspLiterature reference of zsp (z_sp_source) (1)meta.ref;pos.framecharW1-W2? WISE W1-W2 colour (W1-W2)magphot.color;em.IR.3-4um;em.IR.4-8umfloatnullablelog(F2-7)? Chandra hard X-ray F2-7_keV_ (logF2-7_keV_/ergs^-1^cm^-2^)log(0.001W.m**-2)phot.flux;em.X-ray.mediumfloatnullableField[SN-C3/SN-E2/SN-X3] DES deep fields as SN-C3 for 10 cases, SN-E2 for 3 cases and SN-X3 for 2 cases (Field)obs.fieldchar