J/ApJ/835/L30ivo://CDS.VizieR/J/ApJ/835/L30doi:10.26093/cds/vizier.18359030CDSMakarov V.V.Frouard J.Berghea C.T.Rest A.Chambers K.C.Kaiser N.,Kudritzki R.-P.Magnier E.A.2019-08-22T12:04:57Z2017-02-13T15:27:46ZCDS support team

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

cds-question@unistra.frastrometryquasarsWe investigate a sample of 2293 ICRF2 extragalactic radio-loud sources with accurate positions determined by VLBI, mostly active galactic nuclei (AGNs) and quasars, which are cross-matched with optical sources in the first Gaia release (Gaia DR1). The distribution of offsets between the VLBI sources and their optical counterparts is strongly non-Gaussian, with powerful wings extending beyond 1 arcsec. Limiting our analysis to only high-confidence difference detections, we find (and publish) a list of 188 objects with normalized variances above 12 and offsets below 1 arcsec. Pan-STARRS stacked and monochromatic images resolve some of these sources, indicating the presence of double sources, confusion sources, or pronounced extended structures. Some 89 high-quality objects, however, do not show any perturbations and appear to be star-like single sources, yet they are displaced by multiples of the expected error from the radio-loud AGN. We conclude that a fraction of luminous AGNs (more than 4%) can be physically dislodged from the optical centers of their parent galaxies.2017ApJ...835L..30Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/835/L30CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/323 : International Celestial Reference Frame 2, ICRF2 (Ma+, 2009)I/337 : Gaia DR1 (Gaia Collaboration, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/835/L30https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/835/L30http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/835/L30https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/835/L30https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/835/L30http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/835/L30GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/835/L30/table1 (List of 188 objects with normalized variances above 12 and offsets below 1 arcsec)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/835/L30/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/835/L30/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/835/L30/table1?GETtext/xml+votable180.050000true299.41895833.641095380.0055555555555555566/18 532 893 1312 1521 1528 2235 2245 2397 2414 2564 2721 3072 4685 4792 5767 6018 6175 6243 6264 6319 6377 6888 6996 7192 7195 7472 7709 7857 7937 8147 8220 8466 8468 8487 8515 8577 8709 8729 9545 9566 9612 9633 9655 9978 10078 10288 10432 10440 10463 10634 10642 11502 11639 11669 11845 12218 12241 13224 14383 14413 14455 14539 14988 15014 15023 15286 15536 15737 16027 16059 16093 16253 16444 16532 16629 17206 17351 17839 17937 18037 18066 18378 19190 19500 19831 20213 20468 20893 20929 20935 21010 21121 21170 21266 21935 21990 22363 22490 22501 22659 23223 23364 23476 23601 23897 24123 24615 24809 24828 25493 25742 25920 26000 26100 26207 26491 26550 26983 27672 27765 28249 28453 28538 28628 28643 29311 29675 29736 29795 30507 30542 30836 31399 31998 32527 32558 32594 33549 34264 34428 34517 34699 35249 35720 35786 36155 36211 36417 36554 36558 37217 37246 37686 38474 38583 38800 39354 39658 39888 39997 40607 40692 41059 41310 41374 41387 42046 43257 43566 43936 44122 44247 44523 45158 45409 45763 46337 46373 46764 47057 47375 47747 47941 48023 48493 48496 485411.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/835/L30?format=asciidefaultJ/ApJ/835/L30/table1List of 188 objects with normalized variances above 12 and offsets below 1 arcsecrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDelta[0.461/936.284] Absolute difference in position between Gaia and VLBImaspos;arith.diffdoubleICRFICRF2 name (JHHMMSS.s+DDMMSS)meta.id;meta.maincharRAICRSICRF2 right ascension (J2000)degpos.eq.ra;meta.mainDEICRSICRF2 declination (J2000)degpos.eq.dec;meta.mainDisp[DVN] ICRF2 type (1)meta.codecharGmag[14/22] Gaia DR1 magnitude in G bandmagphot.mag;em.opt.Rdoublez? Redshift from OCARSsrc.redshiftfloatnullableAGNtypeMorphological type from OCARS (2)src.morph.typecharNconf[0/30000] Number of Gaia sources within 10 arcminmeta.numberintPneib[0/7] Probability of a chance neighbor within 1 arcsec%statintNotesNotes (3)meta.notecharSimbadSimbad column added by the CDSmeta.ref.urlchar