J/A+A/450/959ivo://CDS.VizieR/J/A+A/450/959doi:10.26093/cds/vizier.34500959CDSOrienti M.Dallacasa D.Tinti S.Stanghellini C.2019-02-27T13:37:00Z2007-01-01T15:03:01ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiquasarsradio-sourcesWe propose a morphological classification based on the parsec scale structure of fifty-one High Frequency Peakers (HFPs) from the "bright" HFP sample. VLBA images at two adjacent frequencies (chosen among 8.4, 15.3, 22.2 and 43.2GHz) have been used to investigate the morphological properties of the HFPs in the optically thin part of their spectrum. We confirm that there is quite a clear distinction between the pc-scale radio structure of galaxies and quasars: the 78% of the galaxies show a "Double/Triple" morphology, typical of Compact Symmetric Objects (CSOs), while the 87% of the quasars are characterised by Core-Jet or unresolved structure. This suggests that most HFP candidates identified with quasars are likely blazar objects in which a flaring self-absorbed component at the jet base was outshining the remainder of the source at the time of the selection based on the spectral shape. Among the sources classified as CSOs or candidates it is possible to find extremely young radio sources with ages of about 100 years or even less.2006A&A...450..959Ohttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/450/959CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/363/887 : High frequency peakers. I. The bright sample (Dallacasa+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/450/959https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/450/959http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/450/959https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/450/959https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/450/959http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/450/959GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/450/959/table2 (The VLBA flux density of candidates High Frequency Peaker)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/450/959/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/450/959/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/450/959/table2?GETtext/xml+votable180.050000true0.7521.48330.0055555555555555566/465 1225 1576 2089 2630 5630 5767 6381 6755 6815 6853 7119 7129 7857 8199 8220 8251 8365 8718 8914 9722 10321 11024 11594 11669 11686 11808 12301 12352 12617 12853 13153 13352 13585 14879 14907 17859 18871 18907 19100 19367 19483 19537 20230 23720 27433 27464 30171 31529 31672 31894 32160 32247 32362 327645.5658981862942334e-24 2.8624621049259595e-23https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/450/959?format=asciiRadiodefaultJ/A+A/450/959/table2The VLBA flux density of candidates High Frequency PeakerrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource name (J2000) (1)meta.id;meta.maincharprimaryCompindicates that the source has individual components flux measurementsmeta.ref.urlcharz? Redshiftsrc.redshiftdoublenullableType[BL EF G Q] Optical type (2)src.classcharS8A? VLA 8.4GHz flux densitymJyphot.flux.density;em.radio.6-12GHzintnullableS8B? VLBA 8.4GHz flux densitymJyphot.flux.density;em.radio.6-12GHzintnullableS15A? VLA 15.3GHz flux densitymJyphot.flux.density;em.radio.12-30GHzintnullableS15B? VLBA 15.3GHz flux densitymJyphot.flux.density;em.radio.12-30GHzintnullableS22A? VLA 22.2GHz flux densitymJyphot.flux.density;em.radio.12-30GHzintnullableS22B? VLBA 22.2GHz flux densitymJyphot.flux.density;em.radio.12-30GHzintnullableS43B? VLBA 43.2GHz flux densitymJyphot.flux.density;em.mm.30-50GHzintnullablealpha? Spectral index (G1)spect.indexfloatnullableHeq? Equipartition magnetic field (G2)mGphys.magFieldintnullableMorphMorphological classification from VLBA images (3)src.morphchar_RARight ascension (derived from Source) for Eq=J2000.0degpos.eq.ra;meta.main_DEDeclination (derived from Source) for Eq=J2000.0degpos.eq.dec;meta.mainJ/A+A/450/959/compComponent VLBA flux density (tables 3 and 4 of paper)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCompsrc.classcharSourceSource name (J2000)meta.id;meta.maincharm_SourceComponent labelmeta.code.multipcharS8B? VLBA flux density at 8.4GHzmJyphot.flux.density;em.radio.6-12GHzintnullableS15B? VLBA flux density at 15.3GHzmJyphot.flux.density;em.radio.12-30GHzintnullableS22B? VLBA flux density at 22.2GHzmJyphot.flux.density;em.radio.12-30GHzintnullableS43B? VLBA flux density at 43.2GHzmJyphot.flux.density;em.mm.30-50GHzintnullablealpha? Spectral index (G1)spect.indexfloatnullablethetamajDeconvolved angular size of major axis (1)masphys.angSizefloatthetaminDeconvolved angular size of minor axis (1)masphys.angSize;srcfloatPA? Position angle of the major axis (1)degpos.posAngintnullableHeqEquipartition magnetic field (G2)1e-07Tphys.magFieldintFreqMax? Turnover frequencyem.freqfloatnullableLAS? Angular distance between componentsmaspos.angDistancefloatnullableLLS? Linear distance between componentspcpos.distanceintnullableNote[*] *: For the sources with redshift unknown, we adopt z=1.00meta.notechar