J/A+A/684/A208ivo://CDS.VizieR/J/A+A/684/A208doi:10.26093/cds/vizier.36840208CDSMayer M.G.F.Becker W.2025-08-21T20:01:06Z2024-04-26T10:00:35ZCDS support team

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

cds-question@unistra.frx-ray-sourcesgamma-ray-astronomypulsarsThe latest source catalog of the Fermi-LAT telescope contains more than 7000 gamma-ray sources at GeV energies, with the two dominant source classes thought to be blazars and rotation-powered pulsars. Despite continuous follow-up efforts, around 2600 sources have no known multiwavelength association. Our target is the identification of possible (young and recycled) pulsar candidates in the sample of unassociated gamma-ray sources via their characteristic X-ray and gamma-ray emission. To achieve this, we cross-match the Fermi-LAT catalog with the catalog of X-ray sources in the western Galactic hemisphere from the first four all-sky surveys of eROSITA on the SRG (Spektrum-Roentgen-Gamma) mission. We complement this by identifying X-ray counterparts of known pulsars detected at gamma-ray and radio energies in the eROSITA data. We use a Bayesian cross-matching scheme to construct a probabilistic catalog of possible pulsar-type X-ray counterparts to Fermi-LAT sources. Our method combines the overlap of X-ray and gamma-ray source positions with a probabilistic classification (into pulsar and blazar candidates) of each source based on its gamma-ray properties and a prediction on the X-ray flux of pulsar- or blazar-type counterparts. Finally, an optical and infrared counterpart search is performed to exclude coronally emitting stars and active galactic nuclei from our catalog. We provide a catalog of our prior gamma-ray-based classifications of all 2600 unassociated sources in the Fermi-LAT catalog, with around equal numbers of pulsar and blazar candidates. Our final list of candidate X-ray counterparts to suspected new high-energy pulsars, cleaned for spurious detections and sources with obvious non-pulsar counterparts, contains around 900 X-ray sources, the vast majority of which lies in the 95% gamma-ray error ellipse. We predict between 30 and 40 new pulsars among our top 200 candidates, with around equal numbers of young and recycled pulsars. This candidate list may serve as input to future follow-up campaigns, looking directly for pulsations or for the orbital modulation of possible binary companions, where it may allow for a drastic reduction in the number of candidate locations to search. We furthermore detect the X-ray counterparts of 15 known rotation-powered pulsars, which were not seen in X-rays before.2024A&A...684A.208Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/684/A208CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIX/67 : Incremental Fermi LAT 4th source cat. (4FGL-DR3)J/A+A/682/A34 : SRG/eROSITA all-sky survey catalogs (eRASS1) (Merloni+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/684/A208https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/684/A208http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/684/A208https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/684/A208https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/684/A208http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/684/A208GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/684/A208/catalog (Full list of candidates with a probability of being a pulsar-type counterpart P_i_PSR>0.02)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/684/A208/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/684/A208/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/684/A208/catalog?GETtext/xml+votable180.050000true236.0641766760492-25.92527895765940.005555555555555556Cone search capability for table J/A+A/684/A208/cand (Corresponding list of sources which failed visual inspection)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/684/A208/cand?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/684/A208/cand?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/684/A208/cand?GETtext/xml+votable180.050000true94.147213352682422.57699125999560.0055555555555555565/7201 9814 10444 10549 10641 10762 6/6446 6678 20702 20745 20805 20843 20845 21329 21385 21394 21399 21401 21428 21483 21487 21526 21641 21645-21648 21658 21662 22039 22044-22045 22088 22117 22678 22848 22858 22868 22871 23501 23554-23555 23563 23567 23590 23600 23610 23631 23669 23673-23674 23739 23766 23774 23798 23810 23946 23969-23971 23980 23982 23995-23996 24183 24208 24320 24325 24370 24378 24433 24663 24788 26192 26237 27231 28506 28675 28680 28684 28696 28702-28703 28709-28710 28712 28715-28716 28718 28727 28729-28731 28800-28801 28803 28817-28820 28822 28824 28834 28837-28839 28841-28846 28848-28850 28856 28858 29191 29200 29226 29317 29322 32775 32832 34392 34871 34928 35807 37046 37152 37202 37228 37233 37241 37310 37321 37356 37365-37366 37369 37372-37373 37534 37554 37648-37649 37663 37669 37673 37726-37727 37750 37752 37775 37816 37819 37837 37839 37844 37846 37848-37850 37852 37872 37874 37878 37882-37884 37886 37893 37899-37900 37902 37908-37909 37924 37928 37931 37952 38006 38016 38018-38019 38026 38049 38052 38055 38178 38410 38508 39111 39174-39175 39200 39248-39249 39252 39273 39280 39283 39304 39308 39341 39345 39387 39437 39439 39640 39733 39792 39804 39882-39883 39906 40127 40183 40402 40496-40497 40618 41014 41019 41115 41208 41257 41340 41350 41355 41380 41390 41392 41399 41402-41403 41405-41407 41434 41437 41448-41449 41451 41456 41460 41474 41545 41551 41561-41563 41568 41573-41575 41579 41586 41589 41599 41606 41612-41613 41622 41631 41636 41642 41655 41657 41661 41680 41682-41686 41688 41692 41695-41697 41699 41709 41714 41716 41718 41722 41729 41733 41735 41742 41744 41749-41750 41759 41764 41766-41767 41770 41773 41780 41790 41815 41823 41835 41841 41853 41863 41874 41877 41882 41889 41894 41900 41908 41917 41924 42039 42042 42091 42098 42107 42110-42111 42114 42116-42117 42122 42124 42126 42131-42132 42135 42142-42143 42147 42150 42156 42159 42169-42174 42180 42184 42186 42191 42193-42194 42202 42205 42207 42210-42213 42215-42217 42219 42221 42223-42224 42226 42229 42234 42237 42299-42300 42302-42303 42311 42318 42339 42341-42342 42345-42348 42350-42351 42363 42366-42367 42369-42372 42374 42378-42379 42382 42385 42388 42390 42392 42397-42398 42406 42417 42420 42429 42432-42433 42435-42436 42438 42445 42448 42450 42452 42454 42456 42460-42462 42465-42466 42482-42483 42485-42487 42496 42498 42504 42510 42514 42518 42521 42523 42525 42527 42533 42541 42552 42570 42572 42574 42578 42580 42593 42600 42614 42632 42635 42641 42679 42756-42757 42766-42767 42779 42804 42806 42829 42837 42849 42856 42860 42869-42870 42927 42977 42983 42989 42992 43010 43017 43019 43040 43042-43043 43062 43082 43109 43136-43138 43146 43150 43171 43174 43227-43229 43231 43243 43246 43253 43265 43280 43309 43339 43392 43467 43552 43593 43651 43660 43860 44102 44129 44155 44212 44302 44314 44374 44514 44569 44585 44817 44838 44984 45078-45079 45397 45446 45496 45640 45874 46057 46361 46534 47127 47305 47310 47332 47655 47753 47771 47784https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/684/A208?format=asciiGamma-rayX-rayRadiodefaultJ/A+A/684/A208/catalogFull list of candidates with a probability of being a pulsar-type counterpart P_i_PSR>0.02recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRank of X-ray source by match probabilitymeta.idintRA_ICRSRight ascension (ICRS) of X-ray sourcedegpos.eq.ra;meta.mainPriorfrMSPLikelihood ratio, assuming millisecond pulsar nature, of having a match rather than a background X-ray source based on only X-ray and gamma-ray fluxes (Eqs. 6 and 7)stat.likelihooddoublePiPSRCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of pulsar naturestat.fit.goodnessdoublePiAGNCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of AGN (blazar) naturestat.fit.goodnessdoubleSimbadSimbad column added by the CDSmeta.ref.urlcharDE_ICRSDeclination (ICRS) of X-ray sourcedegpos.eq.dec;meta.maineposOne-sigma positional error of X-ray sourcearcsecstat.error;posdoubleDetLikeX-ray detection likelihoodstat.likelihooddoubleExtLikeX-ray extent likelihoodstat.likelihooddoubleCRX-ray count rate in 0.2-2.3keVct/sphot.count;em.X-raydoubleFeRASSX-ray source flux in 0.2-2.3keV, determined via an energy conversion factor from the count ratemW.m**-2phot.flux;em.X-raydoubleName4FGLName of gamma-ray source in 4FGL-DR4 catalogmeta.idcharClass2-4FGLClass of low-probability association of gamma-ray source in 4FGL-DR4 catalogmeta.code.classcharAssoc2-4FGLLow-probability association of gamma-ray source in 4FGL-DR4 catalogstat.fit.goodnesscharRA4deg4FGL right ascension (ICRS) of gamma-ray sourcedegpos.eq.raDE4deg4FGL declination (ICRS) of gamma-ray sourcedegpos.eq.decamaj4FGLSemi-major axis of gamma-ray 95% error ellipsearcminphys.angSize.smajAxis;pos.errorEllipsedoublebmin4FGLSemi-minor axis of gamma-ray 95% error ellipsearcminphys.angSize.sminAxis;pos.errorEllipsedoublephi4FGLPosition angle of gamma-ray error ellipse on the skydegpos.posAng;pos.errorEllipsedoublenu4FGLDensity of eRASS:4 X-ray sources within a 2 deg radius around gamma-ray sourcedeg**-2src.densitydoubleExpFieldExpectation value for the number of X-ray chance alignments (denominator in Eq. 4)meta.numberdoubleF4FGLgamma-ray source flux in the range 100 MeV - 100 GeVmW.m**-2phot.flux.density;em.gamma.harddoublePriorPSRPrior probability for a source to be a pulsar, rather than blazar, based on its gamma-ray propertiesstat.fit.goodnessdoublePrioryoungoldPrior probability for a source to be a young pulsar, rather than millisecond pulsar, based on its gamma-ray propertiesstat.fit.goodnessdoubledmahalanobisMahalanobis distance, i.e. the distance between X-ray and gamma-ray source positions, normalized by the total positional error in the given directionpos.distancedoubleBFposPurely positional Bayes factor of the association, i.e. value of Eq. 4 with c = 1.posdoublelogFluxratioLogarithmic gamma-to-X-ray flux ratiophot.flux;arith.ratiodoublePriorfrAGNLikelihood ratio, assuming AGN nature, of having a match rather than a background X-ray source based on only X-ray and gamma-ray fluxes (Eqs. 6 and 7)stat.likelihooddoublePriorfrYNGLikelihood ratio, assuming young pulsar nature, of having a match rather than a background X-ray source based on only X-ray and gamma-ray fluxes (Eqs. 6 and 7)stat.likelihooddoublePiYNGCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of young pulsar naturestat.fit.goodnessdoublePiMSPCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of millisecond pulsar naturestat.fit.goodnessdoublePiCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matchedstat.fit.goodnessdoubleCommentComment on the match, for instance, on possible alternative nature of the X-ray sourcemeta.notecharplotsSee the pdf filemeta.ref.urlchar4eRASSeROSITA source ID following IAU naming conventions (4eRASS JHHMMSS.s+DDMMSS)meta.id;meta.maincharJ/A+A/684/A208/candCorresponding list of sources which failed visual inspectionF4FGLgamma-ray source flux in the range 100MeV-100GeVmW.m**-2phot.flux.density;em.gamma.harddoublePriorPSRPrior probability for a source to be a pulsar, rather than blazar, based on its gamma-ray propertiesstat.fit.goodnessdoubleBFposPurely positional Bayes factor of the association, i.e. value of Eq. 4 with c=1posdoublePiMSPCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of millisecond pulsar naturestat.fit.goodnessdoublePiCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matchedstat.fit.goodnessdoubleCommentComment on the match, for instance, on possible alternative nature of the X-ray sourcemeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRank of X-ray source by match probabilitymeta.idchar4eRASSeROSITA source ID following IAU naming conventionsmeta.id;meta.maincharRA_ICRSRight ascension (ICRS) of X-ray sourcedegpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) of X-ray sourcedegpos.eq.dec;meta.maineposOne-sigma positional error of X-ray sourcearcsecstat.error;posdoubleDetLikeX-ray detection likelihoodstat.likelihooddoubleExtLikeX-ray extent likelihoodstat.likelihooddoubleCRX-ray count rate in 0.2-2.3keVct/sphot.count;em.X-raydoubleFeRASSX-ray source flux in 0.2-2.3keV, determined via an energy conversion factor from the count ratemW.m**-2phot.flux;em.X-raydoubleName4FGLName of gamma-ray source in 4FGL-DR4 catalogmeta.idcharClass2-4FGLClass of low-probability association of gamma-ray source in 4FGL-DR4 catalogmeta.code.classcharAssoc2-4FGLLow-probability association of gamma-ray source in 4FGL-DR4 catalogstat.fit.goodnesscharRA4degRight ascension (ICRS) of gamma-ray sourcedegpos.eq.raDE4degDeclination (ICRS) of gamma-ray sourcedegpos.eq.decamaj4FGLSemi-major axis of gamma-ray 95% error ellipsearcminphys.angSize.smajAxis;pos.errorEllipsedoublebmin4FGLSemi-minor axis of gamma-ray 95% error ellipsearcminphys.angSize.sminAxis;pos.errorEllipsedoublephi4FGLPosition angle of gamma-ray error ellipse on the skydegpos.posAng;pos.errorEllipsedoublenu4FGLDensity of eRASS:4 X-ray sources within a 2deg radius around gamma-ray sourcedeg**-2src.densitydoubleExpFieldExpectation value for the number of X-ray chance alignments (denominator in Eq. 4)meta.numberdoublePrioryoungoldPrior probability for a source to be a young pulsar, rather than millisecond pulsar, based on its gamma-ray propertiesstat.fit.goodnessdoubledmahalanobisMahalanobis distance, i.e. the distance between X-ray and gamma-ray source positions, normalized by the total positional error in the given directionpos.distancedoublelogFluxratioLogarithmic gamma-to-X-ray flux ratiophot.flux;arith.ratiodoublePriorfrAGNLikelihood ratio, assuming AGN nature, of having a match rather than a background X-ray source based on only X-ray and gamma-ray fluxes (Eqs. 6 and 7)stat.likelihooddoublePriorfrYNGLikelihood ratio, assuming young pulsar nature, of having a match rather than a background X-ray source based on only X-ray and gamma-ray fluxes (Eqs. 6 and 7)stat.likelihooddoublePriorfrMSPLikelihood ratio, assuming millisecond pulsar nature, of having a match rather than a background X-ray source based on only X-ray and gamma-ray fluxes (Eqs. 6 and 7)stat.likelihooddoublePiPSRCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of pulsar naturestat.fit.goodnessdoublePiAGNCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of AGN (blazar) naturestat.fit.goodnessdoublePiYNGCombined posterior probability (Eq. 8) for the given X-ray and gamma-ray source to be matched, and to be of young pulsar naturestat.fit.goodnessdoubleJ/A+A/684/A208/priorResult of our machine-learning based prior classification of gamma-ray sources into possible young/millisecond pulsars and blazarsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName4FGLName of gamma-ray source in 4FGL-DR4 catalog (4FGL JHHMM.m+DDMM)meta.id;meta.maincharPriorPSRPrior probability for a source to be a pulsar, rather than blazar, based on its gamma-ray propertiesstat.fit.goodnessdoublePrioryoungoldPrior probability for a source to be a young pulsar, rather than millisecond pulsar, based on its gamma-ray propertiesstat.fit.goodnessdoubleSymLonSymmetric Galactic longitudepos.galactic.londoubleSymLatSymmetric Galactic latitudepos.galactic.latdoublelogVarIndlog variability indexmeta.code;src.var.indexdoubleFracVarFractional variabilityem.freq;src.vardoublePowerLawIndPower law index, PL_Indexspect.indexdoublelogParIndlog-parabola Index, LP_Indexspect.indexdoubleDeltaIndDifference between power law and log-parabola indices, LP_Index - PL_Indexspect.indexdoubleLogParBetalog-parabola beta parameterspect.indexdoublelogSigCurv? Curvature significance for the log-parabola model LPSigCurv scales with the source detection significance,spect.indexdoublenullablen_logSigCurv[I] I for infinitymeta.notecharModSigCurv? 3logLP_SigCurv-2logSignif_Avg valuestat.fit.paramdoublenullablen_ModSigCurv[I] I for infinitymeta.codecharEPivotPivot Energyphys.energydoubleEFluxErrlogUnc_Energy_Flux100-0.4logEnergy_Flux100 valuestat.fit.paramdoubleSigCombined? 3logLP_SigCurv - logVariability_Index valuestat.fit.paramdoublenullablen_SigCombined[I] I for infinitymeta.notecharHR12Hardness ratio based on bands 0.3-1.0GeV/0.05-0.3GeVphot.flux;arith.ratiodoubleHR23Hardness ratio based on bands 1.0-3.0GeV/0.3-1.0GeVphot.flux;arith.ratiodoubleHR34Hardness ratio based on bands 3-30GeV/1.0-3.0GeVphot.flux;arith.ratiodoubleHR45Hardness ratio based on bands 30-1000GeV/3-30GeVphot.flux;arith.ratiodoubleK13Curvature parameter based on bands 1.0-3.0GeV/0.3-1.0GeV/0.05-0.3GeVstat.fit.paramdoubleK24Curvature parameter based on bands 3-30GeV/1.0-3.0GeV/0.3-1.0GeVstat.fit.paramdoubleK35Curvature parameter based on bands 30-1000GeV/3-30GeV/1.0-3.0GeVstat.fit.paramdouble