J/ApJ/852/48ivo://CDS.VizieR/J/ApJ/852/48doi:10.26093/cds/vizier.18520048CDSSaripalli L.Roberts D.H.2018-10-23T07:57:03Z2018-09-19T15:48:38ZCDS support team

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

cds-question@unistra.frradio-galaxiesradio-continuum-emissionvisible-astronomysloan-photometrygalaxy-classification-systemsIn an earlier paper, we presented Jansky Very Large Array multi-frequency, multi-array continuum imaging of a unique sample of low-axial ratio radio galaxies. In this paper, the second in the series, we examine the images to learn the phenomenology of how the off-axis emission relates to the main radio source. Inversion-symmetric offset emission appears to be bimodal and to originate from one of two strategic locations: outer ends of radio lobes (outer-deviation) or from inner ends (inner-deviation). The latter sources are almost always associated with edge-brightened sources. With S- and Z-shaped sources being a subset of outer-deviation sources, this class lends itself naturally to explanations involving black hole axis precession. Our data allow us to present a plausible model for the more enigmatic inner-deviation sources with impressive wings; as for outer-deviation sources these too require black hole axis shifts, although they also require plasma backflows into relic channels. Evolution in morphology over time relates the variety in structures in inner-deviation sources including XRGs. With features such as non- collinearities, central inner-S "spine," corresponding lobe emission peaks, double and protruding hotspots not uncommon, black hole axis precession, drifts, or flips could be active in a significant fraction of radio sources with prominent off-axis emission. At least 4% of radio galaxies appear to undergo black hole axis rotation. Quasars offer a key signature for recognizing rotating axes. With a rich haul of sources that have likely undergone axis rotation, our work shows the usefulness of low-axial ratio sources in pursuing searches for binary supermassive black holes.2018ApJ...852...48Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/852/48CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/133/2097 : FIRST "Winged" and X-shaped radio source cand. (Cheung, 2007)J/ApJS/181/548 : X-shaped radio sources. II. New redshifts (Cheung+, 2009)J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)J/ApJS/220/7 : Abundance of X-shaped radio sources. I. VLA (Roberts+, 2015)J/ApJ/852/47 : "X-shaped" radio sources. I. VLA imaging (Roberts+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/852/48https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/852/48http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/852/48https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/852/48https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/852/48http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/852/48GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/852/48/sample (source properties (tables 1 and 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/852/48/sample?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/852/48/sample?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/852/48/sample?GETtext/xml+votable180.050000true0.4174167-0.56405560.0055555555555555566/4119 4490 4553 4606 5042 5046 5229 5562 5571 5808 5946 6039 6482 6595 6640 6957 7031 7448 8252 8335 8557 8698 8927 9010 9019 9023 9161 9273 9329 9351 9613 9659 9851 9981 10269 10281 10426 10585 10675 10770 10940 10961 10987 11090 11116 11242 11404 11496 11778 17215 17407 17493 17511 17517 17803 18009 18014 18077 18112 25460 25461 25523 25566 25849 25914 25959 26058 26106 26202 26444 26452 26742 27104 27195 27248 27577 27825 28069 28403 28484 28626 28660 31333 36783 40944 45012https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/852/48?format=asciiRadioOpticaldefaultJ/ApJ/852/48/samplesource properties (tables 1 and 2)u_Asym[?] Uncertainty flag on Asymmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[C2007]IAU name (JHHMM+DDMM)meta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainz[0.03/0.9]? Redshift (1)src.redshiftfloatnullablef_z[*] *: photometric redshift from SDSS DR12meta.codecharClassMorphologysrc.classcharLAS[24/177] Largest angular size along the main sourcearcsecphys.angSize;stat.maxintOID?Optical identification? (Q=QSO, BLZ=blazar, BLRG=broad_line radio galaxy, fnt=faint)meta.codecharRad[YN? ] Radio core?meta.codecharXRG?[Y? ] Is the source a candidate "true XRG?"meta.codecharIdev?[Y? ] Inner-deviation-type source? (2)meta.codecharOdev?[NY? ] Outer-deviation-type source? (3)meta.codecharAxis?[Y? ] Axis change?meta.codecharrmag[13.8/23.4]? Host-galaxy apparent r magnitudemagphot.mag;em.opt.Rfloatnullableu_rmag[?] Uncertainty flag on rmagmeta.code.errorcharemLNotes on emission linesmeta.notecharLLS[23/759]? Projected largest linear size based on the radio images and the redshiftskpcphys.size;stat.maxintnullablen_LLSNote on LLS (4)meta.notecharlog(Pt)[24/27.2]? Log of total radio power at 1.4GHzlog(W.Hz**-1)phys.luminosityfloatnullableiEndsGaps between the inner ends of lobes / whether inner ends have sharp edges (5)meta.codecharAsym[0/2.1]? Asymmetry: ratio of longer lobe extent to shorter lobe extent along the main sourcephys.angSize;arith.ratiofloatnullableHs?Are there hotspots? (6)meta.codecharLW?Is the stronger hotspot on the side of the longer wing?meta.codecharPapIDisplay data from Paper I (Roberts+, 2018, J/ApJ/852/47)meta.ref.urlcharSloanDisplay the online SDSS data for the nearest object (if rmag is filled)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar