J/ApJS/209/10ivo://CDS.VizieR/J/ApJS/209/10doi:10.26093/cds/vizier.22090010CDSMassaro F.D'Abrusco R.Paggi A.Masetti N.Giroletti M.Tosti G.,Smith H.A.Funk S.2017-06-01T08:49:38Z2013-12-18T09:18:51ZCDS support team

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

cds-question@unistra.frgamma-ray-astronomyradio-sourcesinfrared-photometryvisible-astronomyphotometryastronomical-object-identificationNearly one-third of the {gamma}-ray sources detected by Fermi are still unidentified, despite significant recent progress in this area. However, all of the {gamma}-ray extragalactic sources associated in the second Fermi-LAT catalog have a radio counterpart. Motivated by this observational evidence, we investigate all the radio sources of the major radio surveys that lie within the positional uncertainty region of the unidentified {gamma}-ray sources (UGSs) at a 95% level of confidence. First, we search for their infrared counterparts in the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) and then we analyze their IR colors in comparison with those of the known {gamma}-ray blazars. We propose a new approach, on the basis of a two-dimensional kernel density estimation technique in the single [3.4]-[4.6]-[12]{mu}m WISE color-color plot, replacing the constraint imposed in our previous investigations on the detection at 22{mu}m of each potential IR counterpart of the UGSs with associated radio emission. The main goal of this analysis is to find distant {gamma}-ray blazar candidates that, being too faint at 22{mu}m, are not detected by WISE and thus are not selected by our purely IR-based methods. We find 55 UGSs that likely correspond to radio sources with blazar-like IR signatures. An additional 11 UGSs that have blazar-like IR colors have been found within the sample of sources found with deep recent Australia Telescope Compact Array observations.2013ApJS..209...10Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/209/10CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/311 : WISE All-Sky Data Release (Cutri+ 2012)I/284 : The USNO-B1.0 Catalog (Monet+ 2003)J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)J/ApJS/209/9 : Unidentified gamma-ray sources. IV. X-ray (Paggi+, 2013)J/ApJS/207/4 : Unidentified {gamma}-ray sources. III. Radio (Massaro+, 2013)J/ApJS/206/17 : New gamma-ray blazar candidates in the 3PBC (Maselli+, 2013)J/ApJS/206/13 : Blazars with {gamma}-ray counterparts. II. (Massaro+, 2013)J/ApJS/206/12 : Blazars with {gamma}-ray counterparts. I. (D'Abrusco+, 2013)J/ApJ/748/68 : WISE IR colors of gamma-ray blazars (D'Abrusco+, 2012)J/ApJ/742/66 : New Fermi/LAT extragalactic sources (Teng+, 2011)J/ApJ/741/30 : Radio/{gamma}-ray correlation in AGN (Ackermann+, 2011)J/ApJ/726/16 : {gamma}-ray loud blazars (Linford+, 2011)J/ApJ/718/587 : The Fermi-AT20G catalog (Mahony+, 2010)J/ApJ/707/L56 : VLBI and bright Fermi/LAT sources (Kovalev, 2009)J/ApJ/706/L7 : The Fermi LAT sky as seen by INTEGRAL/IBIS (Ubertini+, 2009)J/ApJS/135/155 : Radio identification of 3EG EGRET sources (Mattox+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/209/10https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/209/10http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/209/10https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/209/10https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/209/10http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/209/10GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/209/10/table4 (Optical magnitudes for the WISE counterparts)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/209/10/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/209/10/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/209/10/table4?GETtext/xml+votable180.050000true7.83208337.41488890.005555555555555556Cone search capability for table J/ApJS/209/10/ugs (Unidentified Gamma-ray Sources in the Northern and Southern samples and in the SDA sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/209/10/ugs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/209/10/ugs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/209/10/ugs?GETtext/xml+votable180.050000true7.7757.4140.0055555555555555566/428 720 2754 3338 3465 4088 5448 5450 6062 6292 7131 8474 9175 9647 12207 12410 12782 12783 15783 15996 17154 17819 18366 18444 19421 19525 21010 21898 22239 22864 23105 24566 24885 25106 25781 25820 26892 30196 31011 32288 33198 33506 33528 34128 34375 34592 34593 35063 35227 36133 36886 36892 38633 38635 40422 43225 43228 43643 43805 43848 43877 43879 43996 44241 45284 45914 46285 46361 46613 47461 48528https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/209/10?format=asciiGamma-rayOpticalInfraredRadiodefaultJ/ApJS/209/10/table4Optical magnitudes for the WISE counterpartsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWISEWISE designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharB1mag[16.9/20.9]? USNO-B first B-band magnitudemagphot.mag;em.opt.BfloatnullableR1mag[15.7/20.5]? USNO-B first R-band magnitudemagphot.mag;em.opt.RfloatnullableB2mag[15.8/21.5]? USNO-B 2nd B-band magnitudemagphot.mag;em.opt.BfloatnullableR2mag[15.5/21.3]? USNO-B 2nd R-band magnitudemagphot.mag;em.opt.RfloatnullableImag[15.5/19.3]? USNO-B I-band magnitudemagphot.mag;em.opt.IfloatnullableTheta[0.04/2.7] Separation between WISE and optical counterpartarcsecpos.angDistancefloatUSNOCross-match with the USNO-B1 catalog within 3"meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from WISE names (right ascension part)degpos.eq.ra;meta.main_DEPositions from WISE names (declination part)degpos.eq.dec;meta.mainJ/ApJS/209/10/ugsUnidentified Gamma-ray Sources in the Northern and Southern samples and in the SDA sampleNotesNote(s) (2)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSetSouthern, Northern UGS sample ("SU", "NU") or SDA sample ("SDA") (1)src.samplechar2FGL2FGL designation (JHHMM.m+DDMMc)meta.id;meta.maincharOSimbad column added by the CDSmeta.ref.urlcharWISEWISE designation (JHHMMSS.ss+DDMMSS.s)meta.id.crosscharprimaryWDisplay the WISE data for this source (Cutri et al. 2012, Cat. II/311)meta.ref.urlcharRNameRadio name (NVSS, SUMSS or MRSS in table 2; IAU name in table 3)meta.id.crosschar[3.4/4.6][0.48/1.33] WISE [3.4]-[4.6] color indexmagphot.color;em.IR;em.IRfloate_[3.4/4.6][0.03/0.2] [3.4/4.6] 1{sigma} uncertaintymagstat.errorfloat[4.6/12][1.81/3.08] WISE [4.6]-[12] color indexmagphot.color;em.IR;em.IRfloate_[4.6/12][0.03/0.5] [4.6/12] 1{sigma} uncertaintymagstat.errorfloatCL[9.5/97.2] Estimate level of confidence derived from the KDE analysis ({pi}_kde_)stat.fit.goodnessfloatz[0.05/0.2]? Redshift from literaturesrc.redshiftfloatnullableu_z[?] Uncertainty flag on z or unknownmeta.code.error;src.redshiftcharCompComparison with previous analyses (3)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from 2FGL catalog (J/ApJS/199/31) (right ascension part)degpos.eq.ra;meta.main_DEPositions from 2FGL catalog (J/ApJS/199/31) (declination part)degpos.eq.dec;meta.main