J/ApJ/924/54ivo://CDS.VizieR/J/ApJ/924/54doi:10.26093/cds/vizier.19240054CDSPetrov P.Singer L.P.Coughlin M.W.Kumar V.Almualla M.Anand S.,Bulla M.Dietrich T.Foucart F.Guessoum N.2025-02-04T20:09:39Z2023-09-13T14:27:02ZCDS support team

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

cds-question@unistra.frgravitational-wavesneutron-starsblack-holesstellar-distanceSearches for electromagnetic counterparts of gravitational-wave signals have redoubled since the first detection in 2017 of a binary neutron star merger with a gamma-ray burst, optical/infrared kilonova, and panchromatic afterglow. Yet, one LIGO/Virgo observing run later, there has not yet been a second, secure identification of an electromagnetic counterpart. This is not surprising given that the localization uncertainties of events in LIGO and Virgo's third observing run, O3, were much larger than predicted. We explain this by showing that improvements in data analysis that now allow LIGO/Virgo to detect weaker and hence more poorly localized events have increased the overall number of detections, of which well-localized, gold-plated events make up a smaller proportion overall. We present simulations of the next two LIGO/Virgo/KAGRA observing runs, O4 and O5, that are grounded in the statistics of O3 public alerts. To illustrate the significant impact that the updated predictions can have, we study the follow-up strategy for the Zwicky Transient Facility. Realistic and timely forecasting of gravitational-wave localization accuracy is paramount given the large commitments of telescope time and the need to prioritize which events are followed up. We include a data release of our simulated localizations as a public proposal planning resource for astronomers.2022ApJ...924...54Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/924/54CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/795/105 : Electromagnetic follow-up with LIGO/Virgo (Singer+, 2014)J/ApJ/804/114 : Parameter-estimation performance with LIGO (Berry+, 2015)J/ApJ/904/155 : gri photometry for 32 kilonovae with ZTF (Andreoni+, 2020)J/ApJ/905/145 : ZTF candidate counterparts to 13 GW follow-up (Kasliwal+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/924/54https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/924/54http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/924/54https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/924/54https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/924/54http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/924/54GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/924/54/table1Public alerts in O3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSuperevent identifiermeta.id;meta.maincharClassSource classification (1)src.classcharDist[110/5700] Mean a posteriori luminosity distanceMpcpos.distanceintArea[38/24000] 90% credible areadeg**2phys.angSize;phys.areaintVolume[0.17/7600]? 90% credible comoving volume (2)1e+06Mpc**3phys.volumefloatnullableHasNS[0/100] Prob. at least one component <3M_{sun}_%stat.fit.goodnessintRemnant[0/100] Prob. that source tidally disrupted a NS (3)%stat.fit.goodnessintBNS[0/100] Prob. both components are 1-3M_{sun}_ (4)%stat.fit.goodnessintNSBH[0/100] Prob. one mass 1-3M_{sun}_ and one >5M_{sun}_ (4)%stat.fit.goodnessintBBH[0/100] Prob. both masses >5M_{sun}_ (4)%stat.fit.goodnessintMassGap[0/100] Prob. one or both masses are 3-5M_{sun}_ (4)%stat.fit.goodnessintTerr[0/98] Prob. of a non-astrophysical event (4)%stat.fit.goodnessint