J/A+A/691/A287ivo://CDS.VizieR/J/A+A/691/A287doi:10.26093/cds/vizier.36910287CDSNair D.G.Morganti R.Brienza M.Mingo B.Croston J.H.Jurlin N.,Shimwell T.W.Callingham J.R.Hardcastle M.J.2025-02-18T20:02:14Z2024-11-20T07:56:12ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiradio-sourcesRecurrent phases of dormancy and activity occur in the supermassive black holes in active galactic nuclei. Characterizing the duty cycles of this process is crucial in understanding the impact of the energy released on the host galaxies, and their evolution. However, it is challenging to identify sources in the quiescent and restarted phases. Our goal is to identify and characterize a substantial sample of radio galaxies in a restarted phase and explore the idea of core prominence as a signature of restarted activity. We expand our prior study of identifying restarted sources from a 30deg^2^ area in the Lockman Hole to a larger 424deg^2^ region in the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) extragalactic field using a sample of core-dominated radio galaxies selected visually. We used the 144 MHz LOFAR survey images of the HETDEX field to identify galaxies with restarting jets. By assessing diverse selection criteria including radio core dominance along with low surface brightness extended emission, spectral index properties (e.g., steep or inverted spectra of a core and an ultra-steep spectrum of extended emission), and morphology, we found 69 candidate restarted radio galaxies in the HETDEX field. The restarted candidates show a diverse intrinsic morphology, spanning from FRI, FRII, core-with-halo, to asymmetric forms, feasibly proposing different progenitors. Within these 69 restarted candidates, we identified a subset of nine galaxies characterized by ultra-steep spectrum extended emission combined with high radio core prominence, representing previous and current epochs of jet activity. We interpret our findings for this small subset as support for a model in which the switch-on and switch-off mechanism happens with a relatively fast duty cycle in these sources. We found a peculiar case, J131728.61+561544.8, which appears to have altered its jet orientation, possibly due to changes in the angular momentum or spin of its supermassive black hole, interactions with surrounding material, and/or variations in the magnetic flux threading its accretion disk. The restarted candidates span a range of radio luminosities from log_10_(L_144MHz_/(W/Hz)=23.24 to log_10_(L_144MHz_/(W/Hz)=26.80, and linear sizes between 88 and 1659 kpc at 144 MHz, with 16 sources identified as giant radio galaxies with sizes exceeding 0.7Mpc. The total stellar content of restarted sources is consistent with massive elliptical galaxies, with at least 17% inhabiting cluster environments. Our findings at z<0.4 suggest that many restarting radio galaxies are not found in rich cluster environments, aligning with the environmental properties of the broader radio-galaxy population. The present study confirms the core prominence as an effective parameter for selecting candidate restarted radio sources.2024A&A...691A.287Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/691/A287CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/691/A287https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/691/A287http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/691/A287https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/691/A287https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/691/A287http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/691/A287GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/691/A287/tablea1 (List of 69 candidate restarted radio galaxies)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/691/A287/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/691/A287/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/691/A287/tablea1?GETtext/xml+votable180.050000true162.359208347.48305560.005555555555555556Cone search capability for table J/A+A/691/A287/tablea3 (Excluded sources from restarted galaxy sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/691/A287/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/691/A287/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/691/A287/tablea3?GETtext/xml+votable180.050000true164.8417552.65058330.0055555555555555566/5503 5566-5567 5582 5587 5590-5591 5601 5603 5605 5610 5616 5619 5630 5907 5909 5912 5917 5919 5949 5952 5954-5955 5962-5963 5966 5971 5975 5982 5986 5990 5992 6002 6008 6039 6082 10687 10713 10725 10731 10738 10964-10965 10968 10972 10977 10979-10980 10983 10993 10996 11027 11030 11033 11035 11038 11044-11045 11050 11052-11053 11064 11071 11073 11077-11078 11111 11136 11148 11151-11152 11157 11160 11166 11168 11177 11183 11185 11193 11203 11208 11327 11399 11434 11442 117799.54153977050123e-26 9.276497240453405e-25https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/691/A287?format=asciiRadiodefaultJ/A+A/691/A287/tablea1List of 69 candidate restarted radio galaxiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintzRedshiftsrc.redshiftfloatSint144MHzIntegrated flux density at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloatn_CP1.4GHz[+] Note (2)meta.notecharNo[1/69] Sequential source numbermeta.idintn_Source[*+ ] Note (1)meta.notecharn_z[sp] Redshift spectroscopic (s) or photometric (p)meta.notecharl_CP1.4GHzLimit flag on CP1.4GHzmeta.code.errorcharCP1.4GHzRadio core prominence at 1.4GHzphot.flux.density;em.radio.750-1500MHzfloatSB144MHzSurface brightness at 144MHzmJy.arcmin**-2phot.mag.sbfloatl_alphacoreLimit flag on alphacoremeta.code.errorcharalphacoreCore spectral indexspect.indexfloate_alphacore? Core spectral index errorstat.errorfloatnullablel_alphaextLimit flag on alphaextmeta.code.errorcharalphaextExtended emission SIspect.indexfloate_alphaext? Extended emission SI errorstat.errorfloatnullableSelectionCriteria for restarted galaxies (3)meta.notecharCP144MHzRadio core prominence at 144MHzphot.flux.density;em.radio.100-200MHzfloat_RAPositions from name (right ascension part)degpos.eq.ra;meta.main_DEPositions from name (declination part)degpos.eq.dec;meta.mainn_No[*+ ] Note (1)meta.notecharSourceSource name (J2000 coordinates)meta.id;meta.maincharJ/A+A/691/A287/tablea2Flux densities for candidate restarted galaxiesNo[1/69] Sequential source numbermeta.idintn_No[+* ] Note (1)meta.notecharSourceSource name (J2000 coordinates)meta.id;meta.maincharn_Source[+* ] Note (1)meta.notecharSc1400MHzTotal core flux density at 1400MHzmJyphot.flux.density;em.radio.750-1500MHzfloatl_Sc1400MHz[+] Limit code on Sc1400MHz (2)meta.code.errorcharSp1400MHzPeak core flux density at 1400MHzmJyphot.flux.density;em.radio.750-1500MHzfloatl_Sp1400MHz[+] Limit code on Sp1400MHz (2)meta.code.errorcharStot1400MHzTotal core flux density at 1400MHzmJyphot.flux.density;em.radio.750-1500MHzfloatl_Stot1400MHz[+-] Limit code on Stot1400MHz (2)meta.code.errorcharSc144MHzTotal core flux density at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloatSp144MHzPeak core flux density at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloatL144MHzRadio luminosity at 144MHzW/Hzphys.luminosity;em.radio.100-200MHzdoubleSizeLinear size at 144MHzkpcphys.sizefloatMstellar? Stellar mass1e+11solMassphys.massfloatnullableNVSS[PYN,] NVSS detection (3)meta.codecharFIRST[PYN,] FIRST detection (3)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ/A+A/691/A287/tablea3Excluded sources from restarted galaxy samplel_alphaextLimit flag on alphaextmeta.code.errorcharalphaext? Extended emission SIspect.indexfloatnullablee_alphaext? Extended emission SI errorstat.errorfloatnullableReasonReason for exclusionmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNo[70/99] Sequential source numbermeta.idintn_No[+] Note (1)meta.notecharSourceSource name (J2000 coordinates)meta.id;meta.maincharn_Source[+] Note (1)meta.notecharzRedshiftsrc.redshiftfloatn_z[sp] Redshift spectroscopic (s) or photometric (p)meta.notecharSint144MHzIntegrated flux density at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloatl_CP1.4GHzLimit flag on CP1.4GHzmeta.code.errorcharCP1.4GHzRadio core prominence at 1.4GHzphot.flux.density;em.radio.750-1500MHzfloatn_CP1.4GHz[+] Note (2)meta.notecharSB144MHzSurface brightness at 144MHzmJy.arcmin**-2phot.mag.sbfloatl_alphacoreLimit flag on alphacoremeta.code.errorcharalphacoreCore spectral indexspect.indexfloate_alphacore? Core spectral index errorstat.errorfloatnullable_RAPositions from name (right ascension part)degpos.eq.ra;meta.main_DEPositions from name (declination part)degpos.eq.dec;meta.mainJ/A+A/691/A287/tablea4Flux densities of excluded sourcesn_Sp1400MHz[+] Limit code on Sp1400MHz (2)meta.notecharStot1400MHzTotal core flux density at 1400 MHzmJyphot.flux.density;em.radio.750-1500MHzfloatn_Stot1400MHz[+-] Limit code on Stot1400MHz (2)meta.notecharSc144MHzTotal core flux density at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloatSp144MHzPeak core flux density at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloatL144MHzRadio luminosity at 144MHzW/Hzphys.luminosity;em.radio.100-200MHzdoubleMstellar? Stellar mass1e+11solMassphys.massfloatnullableNVSS[YNP] NVSS detections (3)meta.codecharFIRST[YNP] FIRST detections (3)meta.codecharn_No[+* ] Note (1)meta.notecharSizeLinear size at 144MHzkpcphys.sizefloatn_Sc1400MHz[+] Limit code on Sc1400MHz (2)meta.notecharSp1400MHzPeak core flux density at 1400 MHzmJyphot.flux.density;em.radio.750-1500MHzfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNo[70/99] Sequential source numbermeta.idintSourceSource name (J2000 coordinates)meta.id;meta.maincharn_Source[+* ] Note (1)meta.notecharSc1400MHzTotal core flux density at 1400 MHzmJyphot.flux.density;em.radio.750-1500MHzfloat