J/A+A/699/A55ivo://CDS.VizieR/J/A+A/699/A55doi:10.26093/cds/vizier.36990055CDSFoustoul V.Webb N.A.Mignon-Risse R.Kammoun E.Volonteri M.,Dong-Paez C.A.2025-08-05T20:01:01Z2025-06-30T15:29:13ZCDS support team

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

cds-question@unistra.frgalaxiesvisible-astronomyphotometryorbitsquasarsThe role of mergers in the evolution of massive black holes is still unclear,and their dynamical evolution, from the formation of pairs to binaries and the final coalescence, carries large physical uncertainties. The identification of the elusive population of close massive binary black holes (MBBHs) is crucial to understand the importance of mergers in the formation and evolution of supermassive black holes. It has been proposed that MBBHs may display periodic optical/ultra-violet variability. Optical surveys provide photometric measurements of a large variety of objects, over decades and searching for periodicities coming from galaxies in their long-term optical/UV lightcurves may help identify new MBBH candidates. Using the Catalina Real-Time Transient Survey (CRTS) and Zwicky TransientFacility (ZTF) data, we studied the long-term periodicity of variable sources in the centre of galaxies identified using the galaxy catalogue Glade+. We report 36 MBBHs candidates, with sinusoidal variability with amplitudes between 0.1 and 0.8 magnitudes over 3-5 cycles, through fitting 15 years of data. The periodicities are also detected when adding a red noise contribution to the sine model. Moreover, the periodicities are corroborated through Generalized Lomb Scargle (GLS) periodograms analysis, providing supplementary evidence for the observed modulation. We also indicate 58 objects, that were previously proposed to be MBBH candidates from analysis of CRTS data only. Adding ZTF data clearly shows that the previously claimed modulation is due to red noise. We also created a catalogue of 221 weaker candidates which require further observations over the coming years to help validate their nature. Based on our 36 MBBHs candidates, we expect $\sim$20MBBHs at $z<1$, which is commensurate with simulations. Further observations will help confirm these results.2025A&A...699A..55Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/699/A55CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/249/17 : SDSS QSO DR14 spectral properties (Rakshit+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/699/A55https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/699/A55http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/699/A55https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/699/A55https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/699/A55http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/699/A55GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/699/A55/tablec1 (Parameters of weak MBBH candidates found during the CRTS and ZTF-g joint search)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/699/A55/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/699/A55/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/699/A55/tablec1?GETtext/xml+votable180.050000true246.183343.99450.0055555555555555565/1482 2857 6/5269 5300 5314 5320 5426 5438 5492 5502 5525 5559 5566 5592 5595 5607 5609-5611 5628 5701 5749 5756 5837 5873 5879 5901-5902 5909 5916 5919-5920 5922 5932 5941 5947 5967 5975 5988 5997 6015 6022 6027 6035 6042 6045 6047 6064 6066 6091-6093 7220 7427 7438 7442 7446 7449 7472 7478 7480 7485 7492 7524 9109 9146 9160 9166 9174 9181 9191 9215 9375 9418 9444 9456 9613 9750 9821 9832 9846 9895 9900 9953 9970 10001 10117 10186 10268 10369 10372 10405 10409 10476 10529 10533 10551 10609 10623 10664 10682-10683 10686 10728 10730 10795 10802 10804 10832 10840 10859 10878 10899 10941 10957 10967-10968 10974 10986 10989 10993 11000 11003 11013 11015 11020-11021 11025-11027 11033 11037 11039 11045 11047 11050 11052 11063 11072 11082-11083 11097 11101-11102 11105 11112 11117 11132 11136 11143 11157 11170 11176 11178 11188 11191 11197 11223 11229 11234 11239 11250-11251 11257 11260 11262 11303 11340 11353 11355 11390 11413 11424 11442 11457 11461 11463 11495 11533 11557 11566 11648 11786 11791 11803 11825 11831 11846 11909-11910 11912 11930 11949 28116 28279 28505 28508 28531-28532 28541 28566 28583 28585 28606 32447https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/699/A55?format=asciiOpticaldefaultJ/A+A/699/A55/tablec1Parameters of weak MBBH candidates found during the CRTS and ZTF-g joint searchrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameZTF Object IDmeta.id;meta.mainRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainzRedshiftsrc.redshiftfloatPerFitted perioddtime.period;meta.modelledfloate_PerPeriod errordstat.errorfloatlogMBH? Log10 black hole mass (1)log(solMass)phys.massfloatnullablee_logMBH? Log10 black hole mass error (1)log(solMass)stat.errorfloatnullablerchi2Reduced chi squarestat.fit.chi2floatCRTSobs[Yes No] Does the object has CRTS observations?meta.codechar