J/MNRAS/489/3591ivo://CDS.VizieR/J/MNRAS/489/3591doi:10.26093/cds/vizier.74893591CDSPruzhinskaya M.V.Malanchev K.L.Kornilov M.V.Ishida E.E.O.Mondon F.,Volnova A.A.Korolev V.S.2024-08-20T20:12:59Z2023-02-14T13:16:40ZCDS support team

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

cds-question@unistra.frsupernovaegalaxy-classification-systemsphotometryclassificationvisible-astronomyastronomical-modelsIn the upcoming decade, large astronomical surveys will discover millions of transients raising unprecedented data challenges in the process. Only the use of the machine learning algorithms can process such large data volumes. Most of the discovered transients will belong to the known classes of astronomical objects. However, it is expected that some transients will be rare or completely new events of unknown physical nature. The task of finding them can be framed as an anomaly detection problem. In this work, we perform for the first time an automated anomaly detection analysis in the photometric data of the Open Supernova Catalog (OSC), which serves as a proof of concept for the applicability of these methods to future large-scale surveys. The analysis consists of the following steps: (1) data selection from the OSC and approximation of the pre-processed data with Gaussian processes, (2) dimensionality reduction, (3) searching for outliers with the use of the isolation forest algorithm, and (4) expert analysis of the identified outliers. The pipeline returned 81 candidate anomalies, 27 (33 per cent) of which were confirmed to be from astrophysically peculiar objects. Found anomalies correspond to a selected sample of 1.4 per cent of the initial automatically identified data sample of approximately 2000 objects. Among the identified outliers we recognized superluminous supernovae, non-classical Type Ia supernovae, unusual Type II supernovae, one active galactic nucleus and one binary microlensing event. We also found that 16 anomalies classified as supernovae in the literature are likely to be quasars or stars. Our proposed pipeline represents an effective strategy to guarantee we shall not overlook exciting new science hidden in the data we fought so hard to acquire. All code and products of this investigation are made publicly available. (http://snad.space/osc/)2019MNRAS.489.3591Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/489/3591CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/333 : Sloan Digital Sky Survey-II Supernova Survey (Sako+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/489/3591https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/489/3591http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/489/3591https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/489/3591https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/489/3591http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/489/3591GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/489/3591/tablea1 (List of outliers and their hosts)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/489/3591/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/489/3591/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/489/3591/tablea1?GETtext/xml+votable180.050000true17.3745417-1.08841670.0055555555555555566/3861 4552 5715 6070 6192 8359 8532 9640 9794 10556 10817 11425 11427 13350 14441 14913 17239 17405 17663 17689 17692 17747 17749 17755 17763-17764 17767 17769 17817 17830-17831 17840 17997 17999 18006 18011 18019 18021-18023 18034 18073 18098 18176 18398 18686 18765 18789 18791 18844 18852 18856 19034 19043 19050 19056 19097 19115 19136 19787 21220 23196 23204 26584 26914 26983 27256 27258 27612 30034 30036 30042 30059 30099 32522 34694 40210 48481 48500https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/489/3591?format=asciiOpticaldefaultJ/MNRAS/489/3591/tablea1List of outliers and their hostsSimbadNameSimbad column added by the CDSmeta.idcharnullableRefsReferencesmeta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSupernova namemeta.id;meta.maincharf_Name[ef ] Flag on Name (1)meta.codecharn_Name[1/9] Note on Name (2)meta.noteintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainTypeType of the source (3)src.classcharzCMB? CMB redshiftsrc.redshift;pos.cmbfloatnullableHostHost galaxy namemeta.id.parentcharRAH? Right ascension (J2000) of the Hostpos.eq.ranullableDEH? Declination (J2000) of the Hostpos.eq.decnullableHTypeHost morphological type from Simbadsrc.morph.typecharSepas? Separation of the source from the center of its host galaxy (in arcsec)arcsecpos.angDistancefloatnullableSepkpc? Separation of the source from the center of its host galaxy (in kpc)kpcpos.distancefloatnullableCommentsClassification and comments (4)meta.code.class;src.classchar