J/A+A/628/A69ivo://CDS.VizieR/J/A+A/628/A69doi:10.26093/cds/vizier.36280069CDSShulevski A.Barthel P.D.Morganti R.Harwood J.J.Brienza M.,Shimwell T.W.Rottgering H.J.A.White G.J.Callingham J.R.Mooney S.,Rafferty D.A.2022-03-23T16:28:49Z2019-08-08T08:04:21ZCDS support team

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

cds-question@unistra.frseyfert-galaxiesradio-galaxiesWe have examined the giant radio galaxy 3C 236 using LOFAR at 143MHz down to an angular resolution of 7 arcseconds, in combination with observations at higher frequencies. We used the low frequency data to derive spectral index maps with the highest resolution yet at these low frequencies. We confirm a previous detection of an inner hotspot in the north-west lobe and for the first time observe that the south-east lobe hotspot is in fact a triple hotspot, which may point to an intermittent source activity. Also, the spectral index map of 3C 236 shows that the spectral steepening at the inner region of the northern lobe is prominent at low frequencies. The outer regions of both lobes show spectral flattening, in contrast with previous high frequency studies. We derive spectral age estimates for the lobes, as well as particle densities of the IGM at various locations. We propose that the morphological differences between the lobes are driven by variations in the ambient medium density as well as the source activity history.2019A&A...628A..69Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/628/A69CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/549/A58 : 3C 236 CO maps (Labiano+, 2013)J/A+A/617/A38 : The hydrogen gas outflow in 3C236 (Schulz+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/628/A69https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/628/A69http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/628/A69https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/628/A69https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/628/A69http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/628/A69GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/628/A69/list (List of fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/628/A69/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/628/A69/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/628/A69/list?GETtext/xml+votable180.050000true151.5849634.862310.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/628/A696/5311https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/628/A69?format=asciiRadiodefaultJ/A+A/628/A69/listList of fits filesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullableFreqObserved frequencyMHzem.freqdoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar