J/A+A/696/A97ivo://CDS.VizieR/J/A+A/696/A97doi:10.26093/cds/vizier/bc-nr/ljhCDSDabhade P.Chavan K.Saikia D.J.Oei M.S.S.L.Rottgering H.J.A.2026-07-03T06:36:56Z2026-01-05T09:05:06ZCDS support team

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

cds-question@unistra.frgalaxy-clustersradio-galaxiesTo test the hypothesis that megaparsec-scale giant radio galaxies (GRGs) experience multiple epochs of recurrent activity leading to their giant sizes and to understand the nature of double-double radio galaxies (DDRGs), we have built the largest sample of giant DDRGs from the LOFAR Two Metre Sky Survey (LoTSS) data release 2. This sample comprises 111 sources, including 76 newly identified DDRGs, with redshifts ranging from 0.06 to 1.6 and projected sizes between 0.7Mpc and 3.3Mpc. We conducted a detailed analysis to characterise their properties, including arm-length ratios, flux density ratios of pairs of lobes, and misalignment angles. These measurements allow us to study the symmetry parameters, which are influenced by the immediate and large-scale environments of DDRGs. Our study shows that based on the observed asymmetries of the inner lobes, the cocoons in which the inner lobes of DDRGs grow are often (approximately about 26%) asymmetrically contaminated with surrounding material from the external medium. Our analysis also reveals highly misaligned DDRGs, which could be due to environmental factors and/or changes in the supermassive black hole jet ejection axes. By studying the misalignment angles, we assess the stability of the jets in these systems in relation to their environment. For the first time, we systematically characterised the large-scale environments of DDRGs, identifying their association with dense galaxy clusters and revealing the influence of "cluster weather" on their morphologies. We have discovered a DDRG in a distant galaxy cluster at z~1.4. Our findings empirically confirm that dynamic cluster environments can induce significant misalignment in DDRGs, which aligns with previous simulation predictions and offers insights into how cluster weather shapes their morphology. Additionally, we have identified two gigahertz peaked-spectrum (GPS) candidates in the unresolved cores of the DDRGs, as well as one triple-double candidate, which, if confirmed, would be only the fifth known case. Overall, this study enhances our understanding of the life cycle of radio AGNs and underscores the critical role of the environment in shaping the properties and evolution of giant DDRGs.2025A&A...696A..97Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/696/A97CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/736/21 : Galaxy clusters optical catalog from AMF on SDSS DR6J/ApJ/807/178 : Newly rich galaxy clusters identified in SDSS-DR12J/MNRAS/475/343 : 2MASS, WISE, and SuperCOSMOS clusters of galaxiesJ/MNRAS/500/1003 : Redshifts for galaxies in the HSC-SSP and unWISEJ/A+A/659/A1 : LOFAR Two-metre Sky Survey (LoTSS) DR2 (Shimwell+, 2022)J/A+A/642/A153 : SAGAN. I. New sample + multi-wavelength studiesJ/A+A/660/A59 : SAGAN III. New insights into giant radio quasarshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/696/A97https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/696/A97http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/696/A97https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/696/A97https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/696/A97http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/696/A97GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/696/A97/tablea1 (Properties of 76 newly identified G-DDRGs (upper) and 35 known G-DDRGs (lower) within the LoTSS DR2 sky area)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/696/A97/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/696/A97/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/696/A97/tablea1?GETtext/xml+votable180.050000true0.9412931.656730.005555555555555556Cone search capability for table J/A+A/696/A97/tablea3 (Positions, redshifts, magnitudes, cluster properties, and references for G-DDRGs hosted by BCGs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/696/A97/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/696/A97/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/696/A97/tablea3?GETtext/xml+votable180.050000true0.941291731.65673330.0055555555555555566/902 2144 2569 4952 4963 5055 5061 5108 5245 5369 5378 5436 5564 5591 5697 5750 5876-5877 5883 5909 5911 5940 5948 5997 6475 6489 6520 6622 7180 7187 7190 7221 7262 7312 7326 7506 7576 7595 9053 9125 9150 9163 9207 9278 9398 9616 9630 9841 9854 9882 9885 9925 9935 9941 10029 10260 10340 10356 10373 10476 10501 10548 10613 10618 10701 10742 10809 10821 10936 10951 10971 10979 10986 10998 11005 11042 11066 11101 11168 11175 11208 11240 11301 11329 11343 11348 11357 11399 11435 11462 11787 11822 11858 11864 11866 13321 13577 20067 20117 20204 20257 20392 20417 20428 28585 28620 28643 28651 327499.54153977050123e-26 1.987820871092403e-24https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/696/A97?format=asciiRadiodefaultJ/A+A/696/A97/tablea1Properties of 76 newly identified G-DDRGs (upper) and 35 known G-DDRGs (lower) within the LoTSS DR2 sky arearecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSrNoSequential number (within the sample)meta.recordintn_SrNoParent sample (G1)meta.notecharILTILT name (ILTJHHMMSS.ss+DDMMSS.s) of the sources from the main LoTSS catalogue of Shimwell et al. (2022A&A...659A...1S, Cat. J/A+A/659/A1)meta.id;meta.maincharRAJ2000Right ascension (J2000) of the host galaxy (1)pos.eq.ra;meta.mainDEJ2000Declination (J2000) of the host galaxy (1)pos.eq.dec;meta.mainzRedshiftsrc.redshiftfloatn_z[+] Note on z (2)meta.notecharOutersizeAngular size for outer lobearcsec/kpcphys.angSizeintOutersizePProjected size for outer lobekpcphys.angSizeintInnersizeAngular size for inner lobearcsec/kpcphys.angSizeintInnersizePProjected size for inner lobekpcphys.angSizeintMAOMisalignment angle between outer lobe with coredegpos.posAngfloatMAIMisalignment angle between inner lobe with coredegpos.posAngfloatMAO-IMisalignment angle between outer lobe with inner lobedegpos.posAngfloatRtheta(o)Arm length ratios for outer lobesrc.morph.paramfloatRtheta(in)Arm length ratios for inner lobesrc.morph.paramfloatDirDirection of components in which ratios are taken (3)pos.dirCoscharJ/A+A/696/A97/tablea2Flux densities, flux density ratios and spectral indices for our G-DDRGsS3000(core)? Core flux density from VLASS (3000MHz) (1)mJyphot.flux.density;em.radio.1500-3000MHzfloatnullablee_S3000(core)? Core flux density from VLASS (3000MHz) errormJystat.errorfloatnullablen_S3000(core)[X] Note on S3000(core) (2)meta.notecharalphacore? Two-point or three-point spectral index of the core based on available flux densitiesspect.indexfloatnullablee_alphacore? Two-point or three-point spectral index errorstat.errorfloatnullableNotesNotesmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSrNoSequential number (within the sample)meta.recordintn_SrNoParent sample (G1)meta.notecharILTILT name (ILTJHHMMSS.ss+DDMMSS.s) of the sources from the main LoTSS catalogue of Shimwell et al. (2022A&A...659A...1S, Cat. J/A+A/659/A1)meta.id;meta.maincharRS(o)? Flux density ratios for outer lobephot.flux;arith.ratiofloatnullableRS(in)? Flux density ratios for inner lobephot.flux;arith.ratiofloatnullableDirDirection of components in which ratios are takeninstr.offsetcharS144(Outer)? Integrated flux density a 144MHz for outer lobe (1)mJyphot.flux.density;em.radio.100-200MHzfloatnullablee_S144(Outer)? Integrated flux density a 144MHz for outer lobe errormJystat.errorfloatnullableS144(Inner)? Integrated flux density a 144MHz for inner lobe (1)mJyphot.flux.density;em.radio.100-200MHzfloatnullablee_S144(Inner)? Integrated flux density a 144MHz for inner lobe errormJystat.errorfloatnullableS144(core)? Core flux density from LoTSS (144MHz) (1)mJyphot.flux.density;em.radio.100-200MHzfloatnullablee_S144(core)? Core flux density from LoTSS (144MHz) errormJystat.errorfloatnullableS1400(core)? Core flux density from FIRST (1400MHz) (1)mJyphot.flux.density;em.radio.750-1500MHzfloatnullablee_S1400(core)? Core flux density from FIRST (1400MHz) errormJystat.errorfloatnullablen_S1400(core)[X] Note on S1400(core) (2)meta.notecharJ/A+A/696/A97/tablea3Positions, redshifts, magnitudes, cluster properties, and references for G-DDRGs hosted by BCGsSrNoSequential numbermeta.recordintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000) of G-DDRGs hosted by the brightest cluster galaxiespos.eq.ra;meta.mainDEJ2000Declination (J2000) of G-DDRGs hosted by the brightest cluster galaxiespos.eq.dec;meta.mainClusterNamemeta.id;meta.maincharzSpectroscopic redshiftsrc.redshiftfloatn_z[+] + if photometric redshiftmeta.notecharrmagr magnitudemagphot.mag;em.opt.Rfloatr500? Radius within which the mean density is 500 times the critical density of the UniverseMpcphys.size.radiusfloatnullableRL*500? Cluster richness parametersrc.class.richnessfloatnullableN500? Number of galaxies within r500meta.numberintnullableM500? Mass within r5001e+14solMassphys.massfloatnullablen_M500[*] * for mass from Gao et al., 2020PASP..132b4101G, Cat. J/PASP/132/B4101meta.notecharRefReferencemeta.ref;pos.framechar