J/AJ/166/107ivo://CDS.VizieR/J/AJ/166/107doi:10.26093/cds/vizier.51660107CDSKoshimoto N.Sumi T.Bennett D.P.Bozza V.Mroz P.Udalski A.,Rattenbury N.J.Abe F.Barry R.Bhattacharya A.Bond I.A.Fujii H.,Fukui A.Hamada R.Hirao Y.Silva S.I.Itow Y.Kirikawa R.Kondo I.,Matsubara Y.Miyazaki S.Muraki Y.Olmschenk G.Ranc C.Satoh Y.,Suzuki D.Tomoyoshi M.Tristram P.J.Vandorou A.Yama H.,Yamashita K.MOA Collaboration2024-11-06T20:17:31Z2024-04-29T07:49:09ZCDS support team

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

cds-question@unistra.frgravitational-lensingexoplanetsinfrared-photometryvisible-astronomyphotometryWe report the discoveries of low-mass free-floating planet (FFP) candidates from the analysis of 2006-2014 MOA-II Galactic bulge survey data. In this data set, we found 6111 microlensing candidates and identified a statistical sample consisting of 3535 high-quality single-lens events with Einstein radius crossing times in the range 0.057<tE/days<757, including 13 events that show clear finite-source effects with angular Einstein radii of 0.90<{theta}E/{mu}as<332.54. Two of the 12 events with tE<1day have significant finite-source effects, and one event, MOA-9y-5919, with tE=0.057{+/-}0.016days and {theta}E=0.90{+/-}0.14{mu}as, is the second terrestrial-mass FFP candidate to date. A Bayesian analysis indicates a lens mass of 0.75_-0.46_^+1.23^M{Earth} for this event. The low detection efficiency for short-duration events implies a large population of low-mass FFPs. The microlensing detection efficiency for low-mass planet events depends on both the Einstein radius crossing times and the angular Einstein radii, so we have used image-level simulations to determine the detection efficiency dependence on both tE and {theta}E. This allows us to use a Galactic model to simulate the tE and {theta}E distribution of events produced by the known stellar populations and models of the FFP distribution that are fit to the data. Methods like this will be needed for the more precise FFP demographics determinations from Nancy Grace Roman Space Telescope data.2023AJ....166..107Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/166/107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AcA/50/421 : OGLE-II DIA BUL_SC1 field (Wozniak, 2000)J/A+A/533/A134 : Abundances of microlensed stars in the Bulge (Bensby+, 2011)J/A+A/529/A75 : Limb-darkening coefficients (Claret+, 2011)J/A+A/549/A147 : Abundances microlensed bulge dwarf stars. V. (Bensby+, 2013)J/ApJ/778/150 : Microlensing events toward the Bulge from MOA-II (Sumi+, 2013)J/AJ/154/210 : 2015 high-cadence Spitzer microlensing events (Zhu+, 2017)J/AJ/160/74 : Optical and IR photometry of OGLE-2017-BLG-0406 (Hirao+, 2020)J/AJ/160/148 : RI-band LC of microlens OGLE-2018-BLG-1269Lb (Jung+, 2020)J/ApJ/903/L11 : OGLE and KMTNet light curve OGLE-2016-BLG-1928 (Mroz+, 2020)J/AJ/159/262 : OGLE/KMTnet VI bands photom OGLE-2019-BLG-0551 (Mroz+, 2020)J/AJ/161/126 : I-band LC of the microlensevent KMT-2017-BLG-2820 (Ryu+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/166/107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/166/107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/166/107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/166/107https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/166/107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/166/107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/166/107/table3 (All 6111 visually-identified microlensing events timescale event candidates of tE<1 day)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/107/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/107/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/107/table3?GETtext/xml+votable180.050000true266.19384167-33.646655560.0055555555555555565/7179 7181-7183 7194-7195 7205 7216-7217 7220-7221 7266 6/28702-28703 28709-28711 28713 28715 28722-28723 28770-28771 28774-28775 28792 28794-28795 28798-28799 28804 28816-28817 28819 28828-28829 28872-28874 28876-28877 28888-28890 28893 28972-28973 28975 29056 29058-29059 290682.367228618189496e-19 2.6706780932288093e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/166/107?format=asciiOpticalInfrareddefaultJ/AJ/166/107/table3All 6111 visually-identified microlensing events timescale event candidates of tE<1 dayIDMOA-9y-NNNN sequential identifier (1)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIIDInternal ID, field-chip-subfield-IDmeta.idcharRAJ2000[17/18] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainAlert1Alerted IDmeta.id.assoccharAlert2Second Alerted IDmeta.id.assoccharIcmag[13.6/21]? Catalog star's Ic band magnitudemagphot.mag;em.opt.Ifloatnullablee_Icmag[0.01/3]? Uncertainty in Icmagmagstat.error;phot.magfloatnullableNdata[317/31548] Ndata (2)meta.noteintcriteriaEvent Selection Criteria (3)meta.notecharJ/AJ/166/107/table6Parameters for 6111 visually-identified microlensing eventschi2[79/1363652] {chi}^2^stat.fit.chi2intrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDMOA-9y-NNNN sequential identifier (1)meta.id;meta.maincharprimaryt0[-3637/17229] Time of maximum magnification, Heliocentric Julian Date, HJD-2450000.0dtime.epochdoublee_t0[0/1029] Uncertainty in t0dstat.errordoubletE[0.004/64937738] Einstein radius crossing timedtime.epochdoublee_tE[0/71440870] Uncertainty in tEdstat.errordoubleu0[0/28.1] minimum impact parametersrc.impactParam;stat.mindoublee_u0[0/47.1] Uncertainty in u0stat.errordoublerho[0/10] angular size of the sourcephys.angSizedoublee_rho[0/61.2] Uncertainty in rhostat.errordoubleIsmag[4.63/36.4] Apparent I-band source magnitudemagphot.mag;em.opt.Ifloatdchi2[-1514/76442] {chi}^2^-{chi}^2^_FS_meta.notefloat