J/ApJS/206/13ivo://CDS.VizieR/J/ApJS/206/13doi:10.26093/cds/vizier.22060013CDSMassaro F.D'Abrusco R.Paggi A.Masetti N.Giroletti M.Tosti G.,Smith H.A.Funk S.2023-02-03T11:40:09Z2013-08-30T08:37:42ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsinfrared-photometryquasarsgamma-ray-astronomyastronomical-object-identificationactive-galactic-nucleiredshiftedA significant fraction (~30%) of the high-energy gamma-ray sources listed in the second Fermi Large Area Telescope catalog (2FGL) are still of unknown origin, being not yet associated with counterparts at low energies. We recently developed a new association method to identify if there is a {gamma}-ray blazar candidate within the positional uncertainty region of a generic 2FGL source. This method is entirely based on the discovery that blazars have distinct infrared colors with respect to other extragalactic sources found, thanks to the Wide-field Infrared Survey Explorer (WISE) all-sky observations. Several improvements have also been performed to increase the efficiency of our method in recognizing {gamma}-ray blazar candidates. In this paper we applied our method to two different samples, the first constituted by unidentified {gamma}-ray sources (UGSs), and the second by active galaxies of uncertain type, both listed in the 2FGL. We present a catalog of IR counterparts for ~20% of the UGSs investigated. Then, we also compare our results for the associated sources with those present in the literature. In addition, we illustrate the extensive archival research carried out to identify the radio, infrared, optical, and X-ray counterparts of the WISE-selected, {gamma}-ray blazar candidates. Finally, we discuss the future developments of our method based on ground-based follow-up observations.2013ApJS..206...13Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/206/13CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/311 : WISE All-Sky Data Release (Cutri+ 2012)V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)I/284 : The USNO-B1.0 Catalog (Monet+ 2003)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)J/A+A/495/691 : Multifrequency catalog of blazars, Roma-BZCAT (Massaro+, 2009)J/ApJS/206/13 : New gamma-ray blazar candidates in the 3PBC (Maselli+, 2013)J/ApJS/206/12 : Paper I. (D'Abrusco+, 2013)J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)J/ApJ/743/171 : The 2LAC catalog (Ackermann+, 2011)J/ApJ/718/587 : The Fermi-AT20G catalog (Mahony+, 2010)J/ApJS/175/97 : CGRaBS: survey of {gamma}-ray blazar candidates (Healey+, 2008)J/ApJ/609/564 : Blazar counterparts for 3EG sources (Sowards-Emmerd+, 2004)J/ApJ/537/101 : Optical Study for blazars. I. (Fan+, 2000)J/A+AS/128/315 : BVRI photometry of blazars (Jia Guibin+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/206/13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/206/13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/206/13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/206/13https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/206/13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/206/13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/206/13/ugs (Unidentified gamma-ray sources without gamma-ray analysis flag photometry (tables 3 and 8))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/206/13/ugs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/206/13/ugs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/206/13/ugs?GETtext/xml+votable180.050000true9.742791743.49638890.005555555555555556Cone search capability for table J/ApJS/206/13/ugsw (Unidentified gamma-ray sources with gamma-ray analysis flag photometry (tables 4 and 9))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/206/13/ugsw?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/206/13/ugsw?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/206/13/ugsw?GETtext/xml+votable180.050000true38.57537562.70216670.005555555555555556Cone search capability for table J/ApJS/206/13/agu (Active galaxies of uncertain type photometry (tables 5 and 10))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/206/13/agu?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/206/13/agu?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/206/13/agu?GETtext/xml+votable180.050000true2.344833350.5080.005555555555555556Cone search capability for table J/ApJS/206/13/table7 (UGSs without associated {gamma}-ray blazar candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/206/13/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/206/13/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/206/13/table7?GETtext/xml+votable180.050000true0.6862.340.0055555555555555566/189 289 720 851 968 1054 1094 1264 1342 1538 1791 1957 1965 2028 2100 2439 2754 2808 3054 3099 3130 3234 3338 3441 3465 3479 3492 3649 3652 3784 3871 4080 4088 5352 6062 6292 6306 6498 6787 7131 7405 7767 7936 7951 8100 8474 9175 9417 9647 9855 10427 12164 12251 12410 12444 13278-13279 13960 14263 14619 14658 14683 14738 14904 14906 14976 15003 15272 15305 15400 15468 15483 15486 15652 15783 15996 16087 16358 16816 17154 17341 17822 17844 19332 19421 19616 19724 19999 20021 20481 20606 20836 21010 21140 21164 21447 21493 21626 21647 21656 21758 21806 21898 22083 22239 22241 22243 22246 22249 22683 22849 22855 22864 23105 23227 23338 23513 23882 24307 24340 24482 24564 24635 24798 24853 24885 24980 25142 25234 25468 25781 25820 25857 26363 26848 26850 26892 26897 27138 28681 28716 28736 28748 28754 28804 28816-28817 28821 28823 29180 29207 29758 29771 29816 29881 30196 30330 30341 30343 30573 30601 30743 30813 30957 30991 30999 31003 31011 31092-31093 31221 31720 31778 31822 31837 32034-32035 32050 32185 32249 32288 32628 32739 32904 33059 33198 33238 33356 33464 33467 33506 33528 33818 33865 33898 33929 33959 33968 34038 34085 34128 34375 34593 34871 34968 35063 35079 35187 35333 36394 36615 36688 36719 36892 37040 37183 37310-37311 37479 37487 37519 37688 37752 37779 37852 37874 37881 37884 37886 37991 37994 38026 38112 38369 38488 38511 38610 38759 38873 38911 38931 38937 39111 39142 39210 39544 39777 39889 39963 39969 39974 39978 40113 40143 40205 40329 40474 40533 40585 40680 40811 40904 41047 41073 41110 41217 41510 41524 41571 41619 41735 41837 41942 42005 42150 42173 42188 42212 42235 42261 42311 42335 42530 42571 42583 42596 42744 42853 42945 42976 42993 43003 43029 43040 43060 43085 43109 43112 43156 43186 43194 43265 43280 43435 43531 43596-43597 43643 43805 43863 43877 43888 43985 44011 44153 44241 44253 44284 44313 44540 44582 44592 44654 44777 45284 45293 45316 45586 45618 45774 45836 46370 46392 46501 46534 46569 47107 47277 47398 47442 47461 47630 47675 48227 48528 48573 48773 48844 48957https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/206/13?format=asciiGamma-rayInfrareddefaultJ/ApJS/206/13/ugsUnidentified gamma-ray sources without gamma-ray analysis flag photometry (tables 3 and 8)z? Redshiftsrc.redshiftfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2FGL2FGL name (JHHMM.m+DDMMc)meta.id;meta.maincharNxNumber of studied counterpartsmeta.numberintnullableWISEWISE name (JHHMMSS.ss+DDMMSS.s)meta.id.assoccharprimaryONameOther name (Roma-BZCAT, NVSS, SDSS, AT20G, or NED)meta.idchar[3.4/4.6]WISE 3.4-4.6 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[3.4/4.6]3.4-4.6um color index 1{sigma} uncertaintymagstat.errorfloat[4.6/12]WISE 4.6-12 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[4.6/12]4.6-12um color index 1{sigma} uncertaintymagstat.errorfloat[12/22]WISE 12-22 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[12/22]12-22um color index 1{sigma} uncertaintymagstat.errorfloatTypeObject type (BZB=BL Lac object, BZQ=Flat Spectrum Radio Quasar)src.classcharCl[ABC] Class of the candidate blazar according to our method (1)meta.codecharNoteNotes about associations and classes (2)meta.notecharu_z[?] Uncertainty flag on z (3)meta.code.error;src.redshiftcharFlag[y/n] Reassociation flag (tables 5,6) (4)meta.code.errorcharB1mag? USNO-B1 B1 band magnitudemagphot.mag;em.opt.BfloatnullableR1mag? USNO-B1 R1 band magnitudemagphot.mag;em.opt.RfloatnullableB2mag? USNO-B1 B2 band magnitudemagphot.mag;em.opt.BfloatnullableR2mag? USNO-B1 R2 band magnitudemagphot.mag;em.opt.RfloatnullableImag? USNO-B1 I band magnitudemagphot.mag;em.opt.Ifloatnullable_RAPositions from WISE names (right ascension part)degpos.eq.ra;meta.main_DEPositions from WISE names (declination part)degpos.eq.dec;meta.mainJ/ApJS/206/13/ugswUnidentified gamma-ray sources with gamma-ray analysis flag photometry (tables 4 and 9)WISEWISE name (JHHMMSS.ss+DDMMSS.s)meta.id.assoccharprimaryONameOther name (Roma-BZCAT, NVSS, SDSS, AT20G, or NED)meta.idchar[3.4/4.6]WISE 3.4-4.6 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[3.4/4.6]3.4-4.6um color index 1{sigma} uncertaintymagstat.errorfloat[4.6/12]WISE 4.6-12 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[4.6/12]4.6-12um color index 1{sigma} uncertaintymagstat.errorfloat[12/22]WISE 12-22 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[12/22]12-22um color index 1{sigma} uncertaintymagstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2FGL2FGL name (JHHMM.m+DDMMc)meta.id;meta.maincharNxNumber of studied counterpartsmeta.numberintnullableTypeObject type (BZB=BL Lac object, BZQ=Flat Spectrum Radio Quasar)src.classcharCl[ABC] Class of the candidate blazar according to our method (1)meta.codecharNoteNotes about associations and classes (2)meta.notecharz? Redshiftsrc.redshiftfloatnullableu_z[?] Uncertainty flag on z (3)meta.code.error;src.redshiftcharFlag[y/n] Reassociation flag (tables 5,6) (4)meta.code.errorcharB1mag? USNO-B1 B1 band magnitudemagphot.mag;em.opt.BfloatnullableR1mag? USNO-B1 R1 band magnitudemagphot.mag;em.opt.RfloatnullableB2mag? USNO-B1 B2 band magnitudemagphot.mag;em.opt.BfloatnullableR2mag? USNO-B1 R2 band magnitudemagphot.mag;em.opt.RfloatnullableImag? USNO-B1 I band magnitudemagphot.mag;em.opt.Ifloatnullable_RAPositions from WISE names (right ascension part)degpos.eq.ra;meta.main_DEPositions from WISE names (declination part)degpos.eq.dec;meta.mainJ/ApJS/206/13/aguActive galaxies of uncertain type photometry (tables 5 and 10)u_z[?] Uncertainty flag on z (3)meta.code.error;src.redshiftcharFlag[y/n] Reassociation flag (tables 5,6) (4)meta.code.errorcharB1mag? USNO-B1 B1 band magnitudemagphot.mag;em.opt.BfloatnullableR1mag? USNO-B1 R1 band magnitudemagphot.mag;em.opt.RfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2FGL2FGL name (JHHMM.m+DDMMc)meta.id;meta.maincharNxNumber of studied counterpartsmeta.numberintnullableWISEWISE name (JHHMMSS.ss+DDMMSS.s)meta.id.assoccharprimaryONameOther name (Roma-BZCAT, NVSS, SDSS, AT20G, or NED)meta.idchar[3.4/4.6]WISE 3.4-4.6 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[3.4/4.6]3.4-4.6um color index 1{sigma} uncertaintymagstat.errorfloat[4.6/12]WISE 4.6-12 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[4.6/12]4.6-12um color index 1{sigma} uncertaintymagstat.errorfloat[12/22]WISE 12-22 um color index corrected for Galactic extinctionmagphot.color;em.IR;em.IRfloate_[12/22]12-22um color index 1{sigma} uncertaintymagstat.errorfloatTypeObject type (BZB=BL Lac object, BZQ=Flat Spectrum Radio Quasar)src.classcharCl[ABC] Class of the candidate blazar according to our method (1)meta.codecharNoteNotes about associations and classes (2)meta.notecharz? Redshiftsrc.redshiftfloatnullableB2mag? USNO-B1 B2 band magnitudemagphot.mag;em.opt.BfloatnullableR2mag? USNO-B1 R2 band magnitudemagphot.mag;em.opt.RfloatnullableImag? USNO-B1 I band magnitudemagphot.mag;em.opt.Ifloatnullable_RAPositions from WISE names (right ascension part)degpos.eq.ra;meta.main_DEPositions from WISE names (declination part)degpos.eq.dec;meta.mainJ/ApJS/206/13/table7UGSs without associated {gamma}-ray blazar candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2FGL2FGL name (JHHMM.m+DDMM)meta.id;meta.mainchar_RAPositions from the 2FGL catalog (Cat. J/ApJS/199/31) (right ascension part)degpos.eq.ra;meta.main_DEPositions from the 2FGL catalog (Cat. J/ApJS/199/31) (declination part)degpos.eq.dec;meta.main