J/ApJ/853/68ivo://CDS.VizieR/J/ApJ/853/68doi:10.26093/cds/vizier.18530068CDSPiner B.G.Edwards P.G.2019-01-07T09:40:18Z2018-11-06T16:22:36ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsradio-continuum-emissionredshiftedproper-motionsWe present 88 multi-epoch Very Long Baseline Array (VLBA) images (most at an observing frequency of 8GHz) of 20TeV blazars, all of the high-frequency-peaked BL Lac (HBL) class, that have not been previously studied at multiple epochs on the parsec scale. From these 20 sources, we analyze the apparent speeds of 43 jet components that are all detected at four or more epochs. As has been found for other TeV HBLs, the apparent speeds of these components are relatively slow. About two-thirds of the components have an apparent speed that is consistent (within 2{sigma}) with no motion, and some of these components may be stationary patterns whose apparent speed does not relate to the underlying bulk flow speed. In addition, a superluminal tail to the apparent speed distribution of the TeV HBLs is detected for the first time, with eight components in seven sources having a 2{sigma} lower limit on the apparent speed exceeding 1c. We combine the data from these 20 sources with an additional 18 sources from the literature to analyze the complete apparent speed distribution of all 38 TeV HBLs that have been studied with very long baseline interferometry at multiple epochs. The highest 2{sigma} apparent speed lower limit considering all sources is 3.6c. This suggests that bulk Lorentz factors of up to about 4, but probably not much higher, exist in the parsec-scale radio-emitting regions of these sources, consistent with estimates obtained in the radio by other means such as brightness temperatures. This can be reconciled with the high Lorentz factors estimated from the high-energy data if the jet has velocity structures consisting of different emission regions with different Lorentz factors. In particular, we analyze the current apparent speed data for the TeV HBLs in the context of a model with a fast central spine and a slower outer layer.2018ApJ...853...68Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/853/68CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/609/539 : Kinematics of parsec-scale radio jets (Kellermann+, 2004)J/AJ/133/2357 : Relativistic jets in the RRFID database (Piner+, 2007)J/ApJ/706/1253 : MOJAVE VII. Blazar jet acceleration (Homan+, 2009)J/AJ/137/3718 : 15GHz monitoring of AGN jets with VLBA (Lister+, 2009)J/AJ/138/1874 : MOJAVE. VI. Kinematic analysis of blazar jets (Lister+, 2009)J/ApJ/742/27 : 15GHz and jet properties of MOJAVE blazars (Lister+, 2011)J/ApJ/740/98 : Synchroton peak for blazars and radio galaxies (Meyer+, 2011)J/A+A/545/A117 : Monitoring of Mrk 421 at 15 and 24 GHz (Lico+, 2012)J/ApJ/758/84 : Relativistic jets in the RRFID database. II. (Piner+, 2012)J/A+A/559/A75 : 43GHz observation of the blazar Mrk 421 (Blasi+, 2013)J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)J/ApJ/787/151 : Fitted jet components in BL Lacertae (Cohen+, 2014)J/MNRAS/438/796 : Local radio-galaxy population at 20GHz (Sadler+, 2014)J/ApJ/798/134 : MOJAVE. XII. Acceleration of blazar jets (Homan+, 2015)J/ApJ/810/L9 : 1.5Jy MOJAVE AGN sample and 3FGL data (Lister+, 2015)J/AJ/152/12 : MOJAVE. XIII. 15GHz observations on 1994-2013 (Lister+, 2016)J/ApJ/846/98 : Jet kinematics of blazars at 43GHz with VLBA (Jorstad+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/853/68https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/853/68http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/853/68https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/853/68https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/853/68http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/853/68GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/853/68/table2 (Observed sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/853/68/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/853/68/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/853/68/table2?GETtext/xml+votable180.050000true3.4835103-18.90186470.0055555555555555566/398 615 2295 3023 3431 7038 8374 13705 16796 16806 17843 20624 23134 23835 24027 28138 32261 32345 36342 38797https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/853/68?format=asciiRadiodefaultJ/ApJ/853/68/table5Gaussian modelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBNameB1950 Source Namemeta.id;meta.maincharEpochEpoch of observationyrtime.epochfloatFreq[8.4/15.3] Observing frequencyGHzem.freqfloatComp[0/99] Component ID (1)meta.idintFlux[0.6/119.3] Component flux densitymJyphot.flux.density;em.radio.6-12GHzfloatRad[0.002/22.3] Radial position of component centermaspos.angDistancefloatPA[-180/179] Position angle of component center (2)degpos.posAngfloatAxis[0/12.7] Full-width at half maximum of component major axismasphys.angSize.smajAxisfloatRatio[0.5/1] Axial ratio of componentphys.size.axisRatiofloatPAmaj[-85/88.4] Position angle of major axis (3)degpos.posAngfloatType[0/1] Component type. 0: delta function, 1: Gaussianmeta.codeintJ/ApJ/853/68/table6Apparent component speedsm_BName[1/5] Component IDmeta.code.multipintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBNameB1950 name of the sourcemeta.id;meta.maincharSavg[1/25] Mean flux densitymJyphot.flux.density;em.radiofloatravg[0.3/22] Mean separation from coremaspos.angDistance;stat.meanfloate_ravg[0.01/0.4] ravg uncertaintymasstat.errorfloatpm[-0.3/0.8] Proper motionmas/yrpos.pmfloate_pm[0.005/0.4] pm uncertaintymas/yrstat.errorfloatbeta[-4.2/8] Apparent speed in units of the speed of lightphys.veloc;arith.difffloate_beta[0.04/4.5] beta uncertaintystat.errorfloatf_beta[a] Flag on beta (1)meta.codechar1sig[0.1/4.9]? 1{sigma} lower limit on the apparent speed if greater than zerostat.errorfloatnullable2sig[0.1/3.6]? 2{sigma} lower limit on the apparent speed if greater than zerostat.errorfloatnullableJ/ApJ/853/68/table2Observed sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the TeV high-frequency-peaked BL Lac (HBL)meta.id;meta.maincharCompNumber of component speeds for this source (link to table 6)meta.numberintnullableBNameB1950 name (HHMM+ddd; B1950)meta.idcharprimaryz[0.06/0.6] Redshift from TeVCat unless otherwise indicatedsrc.redshiftfloatr_z[a-d, ] Note(s) on z (1)meta.ref;pos.framecharImg[4/5] Number of VLBA imagesmeta.numberintDate1First epoch of observationtime.epochnullableDate2Last epoch of observationtime.epochnullableNgNumber of Gaussian model data for this source (link to table 5)meta.numberintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharNEDNED column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main