J/A+A/642/A148ivo://CDS.VizieR/J/A+A/642/A148doi:10.26093/cds/vizier.36420148CDSSonnenfeld A.Verma A.More A.Beaten E.Macmillan C.Wong K.C.,Chan J.H.H.Jaelani A.T.Lee C.Oguri M.Rusu C.E.Veldthuis M.,Trouille L.Marshall P.J.Hutchings R.Allen C.O' Donnell J.,Cornen C.Davis C.P.McMaster A.Lintott C.Miller G.2021-04-27T12:29:02Z2020-10-13T10:37:54ZCDS support team

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

cds-question@unistra.frgravitational-lensingredshiftedStrong lenses are extremely useful probes of the distribution of matter on galaxy and cluster scales at cosmological distances, but are rare and difficult to find. The number of currently known lenses is on the order of 1000. We wish to use crowdsourcing to carry out a lens search targeting massive galaxies selected from over 442 square degrees of photometric data from the Hyper Suprime-Cam (HSC) survey. We selected from the S16A internal data release of the HSC survey a sample of ~300000 galaxies with photometric redshifts in the range 0.2<zphot<1.2 and photometrically inferred stellar masses logM*>11.2. We crowdsourced lens finding on this sample of galaxies on the Zooniverse platform, as part of the Space Warps project. The sample was complemented by a large set of simulated lenses and visually selected non-lenses, for training purposes. Nearly 6000 citizen volunteers participated in the experiment. In parallel, we used YattaLens an automated lens finding algorithm, to look for lenses in the same sample of galaxies. Based on a statistical analysis of classification data from the volunteers, we selected a sample of the most promising ~1500 candidates which we then visually inspected: half of them turned out to be possible (grade C) lenses or better. Including lenses found by YattaLens or serendipitously noticed in the discussion section of the Space Warps website, we were able to find 14 definite lenses (grade A), 129 probable lenses (grade B) and 581 possible lenses. YattaLens found half the number of lenses discovered via crowdsourcing. Crowdsourcing is able to produce samples of lens candidates with high completeness and purity, compared to currently available automated algorithms. A hybrid approach, in which the visual inspection of samples of lens candidates pre-selected by discovery algorithms and/or coupled to machine learning is crowdsourced, will be a viable option for lens finding in the 2020s with forthcoming wide area surveys such as LSST, Euclid and WFIRST.2020A&A...642A.148Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/642/A148CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/642/A148https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/642/A148http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/642/A148https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/642/A148https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/642/A148http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/642/A148GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/642/A148/sugohi (SuGOHI catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/642/A148/sugohi?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/642/A148/sugohi?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/642/A148/sugohi?GETtext/xml+votable180.050000true0.3735-0.04490.0055555555555555564/1105 1189 1365 1621 1685 1706 5/1024-1026 1028-1029 2459-2460 2471 2480 2496 4424 4426 4428-4430 4432 4434 4449 4452 4697-4699 4713-4715 4720 4722 4765 4800-4801 4810 5469 6399 6479 6483 6488 6490-6492 6500-6502 6512 6566 6568 6570 6572 6822 6828 6830-6831 6912 9199 10239 6/4108-4109 4111 4120-4122 4128 4134 4137 8192 8194-8195 8200 8224 9641-9644 9646 9815 9818-9822 9831 9833 9835 9844-9845 9848-9849 9877 9879 9882-9883 9895 9897 9899-9902 9904-9905 9907 9910 9912 9924 9929 9988 9992-9993 10147 10150 10153 10155-10156 10158 10583 10589 10599 10605-10608 10610 10647 10662 10668-10670 10672 10676 10688-10690 11008-11009 11264 11266-11267 11272 11424-11426 11520-11521 11524 17405 17525 17527 17533 17535 17669 17671 17675 17677-17679 17701-17703 17709-17711 17724 17726 17741 17760-17761 17770-17771 17774 17787 17793 17805 17807 17812 17816 17818 17845 17856-17857 17863 17865-17866 18008 18010-18011 18013 18021 18034-18035 18038-18039 18067 18070 18073-18074 18078 18081 18085 18088-18090 18092 18095 18105 18122 18144 18177-18178 18185 18679 18685-18687 18750 18766 18769 18771 18774 18776-18777 18780 18785 18787 18800 18808-18809 18811 18830-18832 18836-18838 18841 18843-18844 18847 18849-18851 18865-18869 18872-18874 18876 18878-18879 18885 18892 18895 18910 18912-18913 18917 18925 18933 19021 19023 19044-19045 19047 19053 19056-19057 19059 19064-19065 19067-19068 19071 19156-19157 19208 19210 19213 19215-19218 19220 19224 19226 19229 19234 19236 19246 19252 19329 19331-19332 19456-19457 19459-19461 19464-19465 21836-21837 21861 21872-21873 21875 21880-21881 21883 21886 25590-25591 25593-25595 25853 25911 25913-25915 25927 25931 25956-25958 25972 25975-25976 25989 25991 25995 25998-25999 26012-26014 26016-26017 26021-26023 26025 26029-26030 26032 26034-26036 26052 26054 26056 26165 26171-26173 26175 26187 26189 26191 26193 26201-26202 26215 26217-26218 26222 26246-26247 26251-26253 26255-26257 26259-26260 26262-26263 26270-26271 26277-26279 26284 26286-26287 26292 26298 26304 26316 26318-26319 26329 26336 26869 26950-26951 26954 26956 26959 26977 26981 26989 26992-26994 27000 27196-27197 27211-27212 27214-27216 27224-27225 27235-27238 27240-27241 27245-27248 27258-27260 27269 27271 27273-27275 27277-27281 27285 27292 27294 27318 27328 27330 27333 27336 27344-27346 27370 27652 27656 31400 31402 36794-36795 36842 40950-40951 40955 45049 45051-45052 45054-45055https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/642/A148?format=asciidefaultJ/A+A/642/A148/sugohiSuGOHI catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameDesignation (HSCJHHMMSS.ss+DDMMSS.s)meta.id;phys.atmol.configurationcharRAJ2000Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainzl? Lens spectroscopic redshift (set to -9.999 when unavailable)src.redshift;pos.heliocentricfloatnullablezs? Source spectroscopic redshift (set to -9.999 when unavailable)src.redshift;pos.heliocentricfloatnullablepzl? Lens photometric redshift (set to -9.999 when unavailable)src.redshift.photfloatnullableGrade[ABC] Lens probability (1)meta.codecharRefSuGOHI paper reference (2)meta.bibchar