J/PASJ/70/28ivo://CDS.VizieR/J/PASJ/70/28doi:10.26093/cds/vizier/bj-26-wCDSTominaga N.Tanaka M.Morokuma T.Utsumi Y.Yamaguchi M.S.Yasuda N.,Tanaka M.Yoshida M.Fujiyoshi T.Furusawa H.Kawabata K.S.Lee C.-H.,Motohara K.Ohsawa R.Ohta K.Terai T.Abe F.Aoki W.Asakura Y.,Barway S.Bond I.A.Fujisawa K.Honda S.Ioka K.Itoh Y.Kawai N.,Kim J.H.Koshimoto N.Matsubayashi K.Miyazaki S.Saito T.,Sekiguchi Y.Sumi T.Tristram P.J.2026-03-17T20:05:39Z2020-02-11T11:17:50ZCDS support team

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

cds-question@unistra.frgravitational-wavesvisible-astronomyneutron-starsWe perform a z-band survey for an optical counterpart of the binary neutron star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted transient search covers 23.6deg^2^ corresponding to the 56.6% credible region of GW170817 and reaches the 50% completeness magnitude of 20.6mag on average. As a result, we find 60 candidate extragalactic transients, including J-GEM17btc (also known as SSS17a/DLT17ck). While J-GEM17btc is associated with NGC 4993, which is firmly located inside the 3D skymap of GW170817, the other 59 candidates do not have distance information in the GLADE v2 catalog or NASA/IPAC Extragalactic Database. Among 59 of the candidates, 58 are located at the center of extended objects in the Pan-STARRS1 catalog, while one candidate has an offset. We present location, z-band apparent magnitude, and time variability of the candidates and evaluate the probabilities that they are located within the 3D skymap of GW170817. The probability for J-GEM17btc is 64%, which is much higher than for the other 59 candidates (9.3x10^-3^-2.1x10^-1^%). Furthermore, the possibility that at least one of the other 59 candidates is located within the 3D skymap is only 3.2%. Therefore, we conclude that J-GEM17btc is the most likely and distinguished candidate to be the optical counterpart of GW170817.2018PASJ...70...28Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/PASJ/70/28CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/198 : Mark III Catalog of Galaxy Peculiar Velocities (Willick+ 1997)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VII/275 : GLADE catalog (Dalya+, 2016)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers, 2016)IX/55 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR8 (XMM-SSC, 2018)J/A+A/465/71 : 21cm observations of 452 galaxies (Theureau+, 2007)J/MNRAS/444/527 : Tully-Fisher distances for Spitzer galaxies (Sorce+, 2014)J/MNRAS/445/2677 : Peculiar velocities in 6dFGS (Springob+, 2014)J/A+A/588/A103 : 2nd ROSAT all-sky survey (2RXS) catalog (Boller+, 2016)J/ApJ/848/L16 : Counterpart of GW170817. I. DECam. (Soares-Santos+, 2017)J/ApJ/848/L29 : Opt. follow-up of GW170817 counterpart (Diaz+, 2017)J/ApJ/848/L33 : Opt. follow-up of GW events with LCO (Arcavi+, 2017)J/ApJ/851/L21 : UV-NIR obs. compil. of GW170817 counterpart (Villar+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/PASJ/70/28https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/PASJ/70/28http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/PASJ/70/28https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/PASJ/70/28https://vizier.iucaa.in/viz-bin/votable?-source=J/PASJ/70/28http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/PASJ/70/28GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/PASJ/70/28/table5 (The 60 final candidate extragalactic transients)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/PASJ/70/28/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/PASJ/70/28/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/PASJ/70/28/table5?GETtext/xml+votable180.050000true196.1837917-22.61866670.0055555555555555565/6233 6/24853 24896-24897 24899-24900 24902 24904-24905 24910 24929 24937 24940-24942 43935 43978 44000 44002-44003 44008 44010-44011https://cdsarc.cds.unistra.fr/viz-bin/moc/J/PASJ/70/28?format=asciiOpticaldefaultJ/PASJ/70/28/table5The 60 final candidate extragalactic transientsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the candidate; <[TTM2018] J-GEM17aaa> for Simbadmeta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.main