J/ApJ/904/179ivo://CDS.VizieR/J/ApJ/904/179doi:10.26093/cds/vizier.19040179CDSMaithil J.Runnoe J.C.Brotherton M.S.Wardle J.F.Wills B.J.,DiPompeo M.De Breuck C.2022-06-13T09:45:51Z2022-04-05T07:02:16ZCDS support team

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

cds-question@unistra.frquasarsactive-galactic-nucleiradio-spectroscopyredshiftedRadio core dominance measurements, an indicator of jet orientation, sometimes rely on core flux density measurements from large-area surveys like Faint Images of the Radio Sky at Twenty cm (FIRST) that have an angular resolution of only 5". Such low-resolution surveys often fail to resolve cores from the extended emission, resulting in an erroneous measurement. We focus on investigating this resolution effect for a sample of 119 radio-loud quasars. We obtained continuum observations from NSF's Karl G. Jansky Very Large Array (VLA) at 10GHz in A configuration with a 0.2 resolution. Our measurements show that at FIRST spatial resolution, core flux measurements are indeed systematically high even after considering the core variability. For a handful of quasars, 10GHz images reveal extended features, whereas the FIRST image shows a point source. We found that the resolution effect is more prominent for quasars with smaller angular sizes. We further computed two radio core dominance parameters R and R5100 for use in statistical orientation investigations with this sample. We also present the spectral energy distributions between 74MHz and 1.4GHz, which we used to measure the spectral index of the extended emission of these quasars. Our results empirically confirm that determination of radio core dominance requires high spatial resolution data. We highlight the practical issues associated with the choice of frequency and resolution in the measurement of core and extended flux densities.2020ApJ...904..179Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/904/179CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VIII/84 : A final non-redundant catalogue for 7C 151-MHz survey (Hales+ 2007)VII/252 : SDSS-DR5 quasar catalog (Schneider+, 2007)VIII/97 : 74MHz VLA Low-frequency Sky Survey Redux (VLSSr) (Lane+, 2014)J/A+AS/124/259 : Westerbork Northern Sky Survey I. (Rengelink+ 1997)J/A+A/369/380 : CSS/GPS radio sources VLA observations (Fanti+, 2001)J/ApJ/658/203 : VLBA imaging and polarimetry survey at 5GHz (Helmboldt+, 2007)J/AJ/141/182 : Radio and optical properties of QSOs (Kimball+, 2011)J/AJ/147/143 : MOJAVE. XI. Spectral distributions (Hovatta+, 2014)J/MNRAS/454/3864 : Orientation & QSO black hole mass estim. (Brotherton+ 2015)J/A+A/598/A78 : The GMRT 150MHz all-sky radio survey (Intema+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/904/179https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/904/179http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/904/179https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/904/179https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/904/179http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/904/179GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/904/179/table1 (SDSS names, redshifts, optical and radio flux densities, and spectral indices of extended emission of 119 radio-loud quasars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/904/179/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/904/179/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/904/179/table1?GETtext/xml+votable180.050000true113.592473147.48856310.005555555555555556Cone search capability for table J/ApJ/904/179/table4 (Data for 28 additional objects observed with VLA)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/904/179/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/904/179/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/904/179/table4?GETtext/xml+votable180.050000true123.633817856.16574640.0055555555555555566/4949 5016 5041 5071 5212 5263 5306 5359 5406 5415 5441 5448-5449 5469 5485 5505 5507 5552 5597 5672 5710 5731 5749 5773 5800 5807 5817 5845 5894 5928 5983 6004 6064 6111 6120 6264 6352 6460 6462 6481 6484 6490 6543 6549 6551 6607 6628 6640-6641 6644 6934 7223 7226 7238 7245 7269 7272 7280 7310 7318 7341 7358 7368 7381 7396-7397 7448 7479 7488 9127 9138 9146 9151 9181 9184-9185 9191 9193 9320 9327 9375 9404 9608 9616 9632-9633 9637 9754 9768 9876 9900 9925 9932 9961 9965 9988 10181 10217 10329 10420 10428 10550 10557 10630 10641 10706 10710 10757 10881 10900 10919 10945 10969 10976 10987 11010 11029 11053 11079 11124 11138 11160 11162 11172 11183 11202-11203 11224 11274 11287 11290 11332 11337 11364 11402 11426 11462 11491 11793 11822 11832 11856 28527 28575 28599 28610 286173.8949892233750168e-19 3.8949892233750168e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/904/179?format=asciiMillimeterRadiodefaultJ/ApJ/904/179/table1SDSS names, redshifts, optical and radio flux densities, and spectral indices of extended emission of 119 radio-loud quasarsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS identifiermeta.id;meta.maincharprimaryz[0.15/0.6] Spectroscopic redshiftsrc.redshiftfloatF5100[0.17/176] Flux density at 5100{AA} (1)1e-17cW.m**-2.nm**-1phot.flux.densityfloate_F5100[0.1/0.3] Uncertainty in F5100 (1)1e-17cW.m**-2.nm**-1stat.errorfloat10Core[0.53/4895]? 10GHz core flux densitymJy/beamphot.flux.density;em.radio.6-12GHzdoublenullablee_10Core[0.02/3]? Uncertainty in 10CoremJy/beamstat.errorfloatnullableWENSSTot[109/30410] WENSS total flux densitymJyphot.flux.densityintFIRSTCore[0.7/2853] FIRST 1.4GHz core flux densitymJy/beamphot.flux.density;em.radio.750-1500MHzfloate_FIRSTCore[0.1/2] Uncertainty in FIRSTCoremJy/beamstat.errorfloate_WENSSTot[6/1216] Uncertainty in WENSSTotmJystat.errorintTGSSTot[142/53958]? TGSS total flux densitymJyphot.flux.densityfloatnullablee_TGSSTot[15/5397]? Uncertainty in TGSSTotmJystat.errorfloatnullable7CTot[191/56685]? 7C total flux densitymJyphot.flux.densityintnullablee_7CTot[27/2743]? Uncertainty in 7CTotmJystat.errorintnullableVLSSrTot[400/87680]? VLSSr total flux densitymJyphot.flux.densityintnullablee_VLSSrTot[70/7550]? Uncertainty in VLSSrTotmJystat.errorintnullableSpIndex[-1.15/-0.53] Slope of extended emissionspect.indexfloate_SpIndex[0.03/0.2] Uncertainty in SpIndexstat.errorfloatGroupAssigned group based on radio SED (2)meta.idcharlogRLog R and R5100 (table2)meta.ref.urlchar_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.mainnullable_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainnullableJ/ApJ/904/179/table2Logarithm of R and R5100 calculated using new 10GHz and FIRST 1.4GHz core flux densitiesSDSSSDSS identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintR-1.4[-2.62/2.68] log radio core dominance from 1.4GHz core fluxphot.flux.density;em.radio.750-1500MHzfloate_R-1.4[0.03/0.4] Uncertainty in R-1.4stat.errorfloatR-10[-2.23/2.17] log radio core dominance from 10GHz core fluxphot.flux.density;em.radio.6-12GHzfloate_R-10[0.03/0.4] Uncertainty in R-10stat.errorfloatR5100-1.4[0.53/4.79] log R5100 from 1.4GHz core flux densityphot.flux.densityfloate_R5100-1.4[0.001/2] Uncertainty in R5100-1.4stat.errorfloatR5100-10[0.97/4.18] log R5100 from 10GHz core flux densityphot.flux.densityfloate_R5100-10[0.002/2] Uncertainty in R5100-10stat.errorfloatJ/ApJ/904/179/table4Data for 28 additional objects observed with VLAe_F5100[0.2/0.3] Uncertainty in F5100 (1)1e-17cW.m**-2.nm**-1stat.errorfloat10Core[0.62/57.3]? 10GHz core flux densitymJy/beamphot.flux.density;em.radio.6-12GHzfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSDSSSDSS identifiermeta.id;meta.maincharz[0.15/0.6] Spectroscopic redshiftsrc.redshiftfloatF5100[1.39/40.4] Flux density at 5100{AA} (1)1e-17cW.m**-2.nm**-1phot.flux.densityfloate_10Core[0.01/0.5]? Uncertainty in 10GHzCoremJy/beamstat.errorfloatnullableFIRSTCore[1.42/292]FIRST 1.4GHz core flux densitymJy/beamphot.flux.density;em.radio.750-1500MHzfloate_FIRSTCore[0.1/2] Uncertainty in FIRSTCoremJy/beamstat.errorfloatWENSSTot[51/1374] WENSS total flux densitymJyphot.flux.densityinte_WENSSTot[5/55] Uncertainty in WENSSTotmJystat.errorintTGSSTot[42.4/2602]? TGSS total flux densitymJyphot.flux.densityfloatnullablee_TGSSTot[6.1/261]? Uncertainty in TGSSTotmJystat.errorfloatnullable7CTot[108/2460]? 7C total flux densitymJyphot.flux.densityintnullablee_7CTot[17/151]? Uncertainty in 7CTotmJystat.errorintnullableVLSSrTot[460/4130]? VLSSr total flux densitymJyphot.flux.densityintnullablee_VLSSrTot[80/500]? Uncertainty in VLSSrTotmJystat.errorintnullableSpIndex[-1.4/-0.5]Slope of extended emissionspect.indexfloate_SpIndex[0.05/0.3] Uncertainty in Sp+Indexstat.errorfloatGroupAssigned group based on radio SED (2)meta.idcharR-1.4[-1.19/2.02]? log radio core dominance from 1.4GHz core fluxphot.flux.density;em.radio.750-1500MHzfloatnullablee_R-1.4[0.05/0.3]? Uncertainty in R-1.4stat.errorfloatnullableR-10[-1.5/1.5]? log radio core dominance from 10GHz core fluxphot.flux.density;em.radio.6-12GHzfloatnullablee_R-10[0.05/0.3]? Uncertainty in R-10stat.errorfloatnullableR5100-1.4[1.28/3.6]? log R5100 from 1.4GHz core flux densityphot.flux.densityfloatnullablee_R5100-1.4[0.01/0.3]? Uncertainty in R5100-1.4stat.errorfloatnullableR5100-10[0.88/3.25]? log R5100 from 10GHz core flux densityphot.flux.densityfloatnullablee_R5100-10[0.01/0.3]? Uncertainty in R5100-10stat.errorfloatnullable_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.main