J/ApJ/786/20ivo://CDS.VizieR/J/ApJ/786/20doi:10.26093/cds/vizier.17860020CDSLo K.K.Farrell S.Murphy T.Gaensler B.M.2017-09-04T07:58:17Z2017-06-27T10:15:26ZCDS support team

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

cds-question@unistra.frx-ray-sourcesgalaxy-classification-systemsTo maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the Second XMM-Newton Serendipitous Source Catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, and other multi-wavelength contextual information. The 10 fold cross validation accuracy of the training data is ~97% on a 7 class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest derived outlier measure, we identified 12 anomalous sources, of which 2XMM J180658.7-500250 appears to be the most unusual source in the sample. Its X-ray spectra is suggestive of a ultraluminous X-ray source but its variability makes it highly unusual. Machine-learned classification and anomaly detection will facilitate scientific discoveries in the era of all-sky surveys.2014ApJ...786...20Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/786/20CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIX/40 : The XMM-Newton 2nd Incremental Source Catalogue (2XMMi)J/A+A/493/339 : XMM-Newton serendipitous Survey. V. (Watson+, 2009)J/MNRAS/416/1844 : 2XMM ultraluminous X-ray source candidates (Walton+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/786/20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/786/20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/786/20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/786/20https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/786/20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/786/20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/786/20/table7 (2XMM variable sources classification)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/786/20/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/786/20/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/786/20/table7?GETtext/xml+votable180.050000true0.5770833-29.85222220.0055555555555555565/292 6/311 342 351 399 474 485 496 579 597 859 862 1024 1031 1037 1050 1074 1075 1082 1111 1114 1115 1159 1196 1198 1387 1483 1504 1539 1694 1701 1704 1841 1847 1965 2012 2134 2154 2155 2229 2248 2622 2623 2666 2709 2752 3029 3042 3054 3063 3066 3136 3256 3257 3308 3506 3507 3632 3849 3934 3986 4027 4078 4124 4439 4444 4447 4536 4653 4698 4790 4859 4955 5091 5112 5241 5420 5423 5469 5558 5689 5860 6021 6069 6274 6340 6528 6639 7026 7178 7210 7241 7273 7309 7606 7612 7618 7642 7733 7743 7752 7784 7828 7896 8029 8124 8173 8224 8264 8268 8687 8790 8843 8906 8922 8952 9018 9194 9346 9401 9442 9468 9512 9660 9750 10169 10255 10265 10303 10312 10378 10379 10390 10400 10401 10422 10442 10454 10484 10599 10604 10761 10769 10771 10774 10912 10927 10999 11027 11029 11084 11112 11127 11249 11354 11375 11434 11690 11790 11845 11856 11875 11925 12127 12317 12481 12553 12568 12725 12804 12859 13191 13301 13414 13511 13564 13641 13743 13778 13956 14053 14056 14261 14263 14305 14314 14318 14321 14379 14610 14629 14631 14692 14697 14700 15112 15368 15369 15385 15430 15593 15681 16072 16144 16186 16220 16232 16280 16410 16429 16490 16589 16609 16655 16671 16831 17022 17124 17188 17248 17264 17448 17472 17683 17690 17691 17692 17695 17752 17818 18207 18367 18398 18590 18683 18699 18817 18968 19283 19506 19730 19883 20061 20071 20489 20510 20624 20700 20701 20875 21169 21196 21436 21438 21439 22050 22095 22289 22485 22651 22659 22722 22735 22804 22805 22848 22851 22854 22855 22862 22873 22912 22977 23171 23191 23223 23230 23323 23451 23527 23538 23539 23545 23548 23549 23637 23639 23705 23717 23728 23738 23952 24829 24897 24949 24951 25148 25182 25344 25540 25666 25682 25901 25907 25982 26100 26125 26265 26292 26446 26645 26802 26990 27004 27005 27102 27126 27133 27228 27256 27259 27343 27428 27462 27545 27580 27718 27719 27742 27765 27862 27934 27937 27948 27975 27982 28026 28062 28142 28221 28346 28396 28492 28517 28529 28535 28690 28703 28711 28772 28779 28787 28798 28809 28813 28817 28823 28825 28830 28831 28849 28868 28875 28877 28890 28891 28892 28894 28913 28925 28971 29070 29081 29090 29091 29097 29114 29192 29193 29211 29221 29259 29287 29307 29398 29511 29523 29529 29535 29691 29870 30021 30029 30256 30257 30306 30318 30328 30366 30439 30507 30616 30618 30719 30993 31259 31393 31537 31751 31774 31804 31898 32484 32994 33047 33067 33088 33094 33096 33099 33106 33113 33116 33121 33153 33193 33295 33298 33306 33317 33323 33328 33378 33403 33649 33662 33694 33713 33801 33930 33986 34034 34035 34038 34054 34065 34104 34297 34493 34531 34534 34653 34845 35067 35150 35256 35512 35514 35536 35611 35770 35935 36129 36158 36526 36697 36700 36792 36844 36956 36957 36958 37022 37071 37128 37231 37252 37306 37474 37475 37512 37592 37593 37788 37863 37869 37871 37880 37881 37882 37901 37925 37926 37929 37930 37936 37937 38016 38018 38081 38139 38145 38268 38442 38528 38653 38853 38926 39055 39077 39118 39140 39181 39183 39216 39235 39247 39253 39318 39327 39396 39397 39775 39784 39785 39825 39937 40124 40271 40293 40433 40520 40613 40784 40786 40932 40988 41001 41134 41270 41271 41279 41399 41526 41530 41584 41586 41591 41630 41654 41660 41676 41682 41697 41701 41713 41812 41814 41823 42027 42137 42169 42170 42210 42211 42214 42215 42216 42224 42226 42228 42315 42391 42394 42409 42435 42451 42460 42464 42496 42547 42841 42925 42981 42990 43024 43035 43042 43065 43227 43310 43321 43386 43420 43523 43564 43632 43677 43787 43803 43806 43836 43874 43947 44094 44169 44316 44356 44475 44861 44894 45044 45227 45350 45471 45580 45671 45754 45814 45855 45984 46399 46568 46615 46737 46738 46855 46969 47014 47047 47136 47414 47417 47496 47648 47649 47805 47824 47825 47828 48034 48163 48263 48274 49112 49123https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/786/20?format=asciiX-rayOpticaldefaultJ/ApJ/786/20/table72XMM variable sources classificationCMClassification marginstat.fit.goodnessfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName2XMM identifier (2XMM JHHMMSS.s+DDMMSS and 2XMMi JHHMMSS.s+DDMMSS in Simbad)meta.id;meta.maincharPAGNProbability source is an AGNstat.fit.goodnessfloatPCVProbability source is a CVstat.fit.goodnessfloatPGRBProbability source is a GRBstat.fit.goodnessfloatPSSSProbability source is a SSSstat.fit.goodnessfloatPStarProbability source is a starstat.fit.goodnessfloatPULXProbability source is a ULXstat.fit.goodnessfloatPXRBProbability source is a XRBstat.fit.goodnessfloatPmaxMaximum classification probabilitystat.fit.goodnessfloatRFCOutput from Random Forest classifiersrc.classcharSampleSource in known or unknown samplemeta.codecharClassActual class; known sources onlysrc.classcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions form Simbad or Name (right ascension part)degpos.eq.ra;meta.main_DEPositions form Simbad or Name (declination part)degpos.eq.dec;meta.main