J/A+A/658/A10ivo://CDS.VizieR/J/A+A/658/A10doi:10.26093/cds/vizier.36580010CDSBonnassieux E.H.J.Sweijen F.Brienza M.Rajpurohit K.Riseley C.J.,Bonafede A.Jackson N.Morabito L.K.Brunetti G.Harwood J.Kappes A.,Rottgering H.J.Tasse C.van Weeren R.2022-05-18T12:45:34Z2022-01-25T08:52:17ZCDS support team

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

cds-question@unistra.frquasarsradio-sources3C295 is a bright, compact steep spectrum source with a well-studied integrated radio spectral energy distribution (SED) from 132MHz to 15GHz. However, spatially resolved spectral studies have been limited due to a lack of high resolution images at low radio frequencies. These frequencies are crucial for measuring absorption processes, and anchoring the overall spectral modelling of the radio SED. In this paper, we use International LOw-Frequency ARray (LOFAR) Telescope (ILT) observations of 3C295 to study its spatially resolved spectral properties with sub-arcsecond resolution at 132MHz. Combining our new 132MHz observation with archival data at 1.6GHz, 4.8GHz, and 15GHz, we are able to carryout a resolved radio spectral analysis. The spectral properties of the hotspots provides evidence for low frequency flattening. In contrast, the spectral shape across the lobes is consistent with a Jaffe-Perola spectral ageing model. Usingthe integrated spectral information for each component, we then fitted low-frequency absorption models to the hotspots,finding that both free-free absorption and synchrotron self-absorption models provide a better fit to the data than a standard power law. Although we can say there is low-frequency absorption present in the hot spots of 3C295, future observations with the Low Band Antenna of the ILT at 55MHz may allow us to distinguish the type of absorption.2022A&A...658A..10Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/658/A10CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/285/785 : 3C 295 BRri photometry (Thimm+, 1994)J/A+A/658/A2 : LOFAR Long-Baseline Calibrator Survey. II. (Jackson+, 2022)J/A+A/658/A4 : LOFAR imaging of Arp299 at 150MHz (Ramirez-Olivencia, 2022)J/A+A/658/A5 : Hercules A LOFAR and JVLA images (Timmerman+, 2022)J/A+A/658/A6 : 3C293 high and low resolution maps (Kukreti+, 2022)J/A+A/658/A8 : Resolved jet of 3C 273 at 150 MHz (Harwood+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/658/A10https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/658/A10http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/658/A10https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/658/A10https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/658/A10http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/658/A10GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/658/A10/list (List of fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/658/A10/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/658/A10/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/658/A10/list?GETtext/xml+votable180.050000true212.8354952.202730.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/658/A106/10743https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/658/A10?format=asciiRadiodefaultJ/A+A/658/A10/listList of fits filesNxNumber of pixels along X-axismeta.numberintrecnoRecord 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.mainNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar