J/AJ/161/154ivo://CDS.VizieR/J/AJ/161/154doi:10.26093/cds/vizier.51610154CDSKerby S.Kaur A.Falcone A.D.Stroh M.C.Ferrara E.C.Kennea J.A.,Colosimo J.2022-03-07T07:09:03Z2021-04-16T09:56:56ZCDS support team

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

cds-question@unistra.frx-ray-sourcespulsarsactive-galactic-nucleiWe conduct X-ray spectral fits on 184 likely counterparts to Fermi-LAT 3FGL unassociated sources. Characterization and classification of these sources allows for more complete population studies of the high-energy sky. Most of these X-ray spectra are well fit by an absorbed power law model, as expected for a population dominated by blazars and pulsars. A small subset of 7 X-ray sources have spectra unlike the power law expected from a blazar or pulsar and may be linked to coincident stars or background emission. We develop a multiwavelength machine learning classifier to categorize unassociated sources into pulsars and blazars using gamma- and X-ray observations. Training a random forest procedure with known pulsars and blazars, we achieve a cross-validated classification accuracy of 98.6%. Applying the random forest routine to the unassociated sources returned 126 likely blazar candidates (defined as P_bzr_>90%) and 5 likely pulsar candidates (P_bzr_<10%). Our new X-ray spectral analysis does not drastically alter the random forest classifications of these sources compared to previous works, but it builds a more robust classification scheme and highlights the importance of X-ray spectral fitting. Our procedure can be further expanded with UV, visual, or radio spectral parameters or by measuring flux variability.2021AJ....161..154Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/154CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/154https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/154http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/154https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/154https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/154http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/154GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/161/154/3fglfits (X-ray fit and ML classification results (tables 3 and 4 of the paper))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/161/154/3fglfits?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/161/154/3fglfits?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/161/154/3fglfits?GETtext/xml+votable180.050000true2.021958314.83848330.0055555555555555566/50 897 1354 1538 1973 2667 3113 3234 3369 3619 3915 4179 8485 9032 9417 10194 10202 10427 10971 11689 12164 12313 12410 12443 12476 12736 13034 13056 13204 13324 13334 13433 13720 13929 14150 14185 14274 14320 14854 15483 15488 15910 15994 16137 17095 17154 17819 18666 18852 19545 19673 20110 20473 21438 21593 21645 21710 21808 21898 22683 23009 24064 24512 24641 24789 24836 25095 25142 25234 25370 25403 25468 25525 25553 25781 25807 25865 26125 26156 26237 27127 27381 27468 27772 28015 28037 28290 28560 28772 28823 28837 28910 28967 29151 29547 29881 30154 30256 30624 31011 31116 32086 32288 32539 32581 32629 33059 33087 33243 34171 34623 34772 35227 35594 36100 36133 36394 36445 36951 36956 37112 37247 37338 37492 37744 37819 37848 37861 37940 37991 38019 38112 38127 38176 38184 38192 38873 39139 39208 40113 40329 40422 40585 41091 41359 41510 41518 41655 41683 41699 41772 41824 42222 42311 42385 42390 42436 42566 42580 42920 42981 43197 43710 43746 44049 44123 44302 44571 44913 45077 45226 45242 45316 45707 45847 45904 46122 46444 47196 47461 48274 48580 48699 48854 48858 48963https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/161/154?format=asciiX-rayRadiodefaultJ/AJ/161/154/3fglfitsX-ray fit and ML classification results (tables 3 and 4 of the paper)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint3FGLNameFermi-LAT 3FGL catalog name (JHHMM.m+DDMM)meta.id;meta.maincharSwFS3NameSwift-XRT X-ray excess name (JHHMMSS.s+DDMMSS)meta.idcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainPLSlope? X-ray fit photon index, 0.2-10keVspect.indexfloatnullableE_PLSlope? Photon index positive uncertaintystat.error;stat.maxfloatnullablee_PLSlope? Photon index negative uncertaintystat.errorfloatnullableFlux? X-ray fit flux, 0.2-10keVmW.m**-2phot.flux;em.X-raydoublenullableE_Flux? X-ray flux positive uncertaintymW.m**-2stat.error;stat.maxdoublenullablee_Flux? X-ray flux negative uncertaintymW.m**-2stat.error;phot.fluxdoublenullablefitDOF? X-ray fit degrees of freedomstat.fit.dofintnullablefitCstat? X-ray fit C-statisticstat.fit.paramfloatnullableBlazarProb? Random forest blazar probabilitystat.fit.goodnessfloatnullableNotesError message (1)meta.notecharSimbadSimbad column added by the CDSmeta.ref.urlchar