J/ApJ/916/47ivo://CDS.VizieR/J/ApJ/916/47doi:10.26093/cds/vizier.19160047CDSKim J.Im M.Paek G.S.H.Lee C.-U.Kim S.-L.Chang S.-W.Choi C.,Hwang S.Kang W.Kim S.Kim T.Lee H.M.Lim GuSeo J.Sung H.-I.2023-03-20T14:05:32Z2023-01-23T13:15:05ZCDS support team

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

cds-question@unistra.frgravitational-wavesblack-holesphotometryvisible-astronomyWe present optical follow-up observation results of three binary black hole merger (BBH) events, GW190408_181802, GW190412, and GW190503_185404, which were detected by the Advanced LIGO and Virgo gravitational wave (GW) detectors. Electromagnetic (EM) counterparts are generally not expected for BBH merger events. However, some theoretical models suggest that EM counterparts of BBH can possibly arise in special environments, prompting motivation to search for EM counterparts for such events. We observed high-credibility regions of the sky for the three BBH merger events with telescopes of the Gravitational-wave EM Counterpart Korean Observatory (GECKO), including the KMTNet. Our observation started as soon as 100 minutes after the GW event alerts and covered 29-63deg^2^ for each event with a depth of ~22.5mag in the R band within hours of observation. No plausible EM counterparts were found for these events, but based on there being no detection of the GW190503_185404 event, for which we covered the 69% credibility region, we place the BBH merger EM counterpart signal to be M_g_{>}-18.0 AB mag within about one day of the GW event. The comparison of our detection limits with light curves of several kilonova models suggests that a kilonova event could have been identified within hours of the GW alert with GECKO observations if the compact merger happened at <400Mpc and the localization accuracy was on the order of 50deg^2^. Our result shows great promise for the GECKO facilities to find EM counterparts within a few hours from GW detection in future GW observation runs.2021ApJ...916...47Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/916/47CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)VII/281 : GLADE v2.3 catalog (Dalya+, 2018)J/ApJ/766/109 : Color/age/metallicity gradients of E galaxies (Kim+, 2013)J/ApJ/848/L16 : Counterpart of GW170817. I. DECam obs. (Soares-Santos+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/916/47https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/916/47http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/916/47https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/916/47https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/916/47http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/916/47GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/916/47/table2 (Tiling observation of the three GW events)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/916/47/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/916/47/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/916/47/table2?GETtext/xml+votable180.050000true223.059583-41.3811110.005555555555555556Cone search capability for table J/ApJ/916/47/table3 (Galaxy observation of GW190412)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/916/47/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/916/47/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/916/47/table3?GETtext/xml+votable180.050000true198.48416720.5897220.0055555555555555565/2291 2628 7000 6/8959 9070 9086 9117 9123 9131 9135 9142-9144 9146 9148 9151 9155 9158 9161-9163 9168 9170-9171 9174-9177 9184 9186-9188 9190 9192-9193 9195 9200 10325 10327 10496 10503 10516 10560 12546 12558 12592 19197 19374 19435 26273 26278-26279 26285 26291 26297 26301 26344 26346 27665 27729 27733 27737 27909 27911-27912 27917-27919 27921 27923 27930-27932 27935 27940 27942-27943 27956 27958 27960 27977 27981-27983 27992 27994-27995 27998 28005 28007-28008 28013 28016-28018 28020 34581 34626 39053 39073 39079 39081 39096 39428 39433 39435 39437 39461 39465 41981 43345-43346 43350 43355 43380 44032 44040https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/916/47?format=asciiOpticaldefaultJ/ApJ/916/47/table1Target gravitational wave (GW) eventsSimbadNameSimbad column added by the CDSmeta.idcharnullableEventTarget GW event IDmeta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeSource type ("BBH"=binary black hole)meta.code.classcharDateEvent time (UT)stime.epochnullableArea90[156/448] Initial 90% areadeg**2phys.angSizeintDist[412/1473] Initial distanceMpcpos.distanceinte_Dist[105/358] Dist uncertaintyMpcstat.errorintAreaGWTC[21/140] GWTC-2 90% areadeg**2phys.angSizeintDistGWTC[740/1580] GWTC-2 distanceMpcpos.distanceinte_DistGWTC[170/660] Lower uncertainty on DistGWTCMpcstat.errorintE_DistGWTC[140/710] Upper uncertainty on DistGWTCMpcstat.error;stat.maxintl_FARUpper limit flag on FARmeta.code.errorcharFAR[7.9e-5] False alarm rate taken from the result of PyCBC BBH pipeline in the GWTC-2 catalog (Abbott+ 2021PhRvX..11b1053A)yr**-1time;arith.ratiodoubleNobsNumber of follow-up observations for this event (link to Table 2)meta.numberintnullableLCInteractive Plot from Table 2 datameta.ref.urlcharJ/ApJ/916/47/table2Tiling observation of the three GW eventsEventGravitational wave event identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTelTelescope identifier (1)meta.id;instr.telcharObs[2019] Year of the observation start timestime.epochTime[1.6/89.2] Time since GW alerthtime.epochfloatRAJ2000[4/22] Hour of Right Ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000[0/55] Degree of Declination (J2000) (2)pos.eq.dec;meta.mainBandFilter used (B, V or R)meta.code;instr.filtercharDepth[17/23.3] Image depth in 5-sigma; ABmagphot.mag;instr.sensitivityfloatJ/ApJ/916/47/table3Galaxy observation of GW190412SimbadNameSimbad column added by the CDSmeta.idcharnullableNEDnameNED column added by the CDSmeta.idcharLEDAmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs[2019] Year of the observation start timestime.epochNameTarget identifier (2)meta.id;meta.maincharRAJ2000[12/15] Hour of Right Ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000[0/36] Degree of Declination (J2000) (2)pos.eq.dec;meta.mainBandFilter used (B, V, R or I)meta.code;instr.filtercharDepth[15.7/21.4] Image depth in 5-sigma; ABmagphot.mag;instr.sensitivityfloatGLADEDisplay the GLADE v2.3 cat. (VII/281) within 3"meta.ref.urlcharTelTelescope identifier (1)meta.id;instr.telchar