Pol. cubesivo://astron.nl/apertif_dr2/q/apertif_dr2_polarization_cubesASTRONApertif Team2026-04-10T15:23:43Michael Sipior

Oude Hoogeveensedijk 4, 7991PD Dwingeloo, the Netherlands

vo@astron.nlHI lineradio Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), providing forty instantaneous beams over 300 MHz of bandwidth. A description of the second data release is to be included here. This service queries the polarization cubes from the second data release of Apertif. In order to prevent bandwidth depolarization and enable rotation measure synthesis studies, Stokes Q and U cubes with a frequency resolution of 6.25 MHz are produced. The cubes have a smaller spatial extent of 2.7 deg × 2.7 deg (2049 × 2049 pixels, with 4''/pixel ) than the continuum or Stokes V images but still extend well beyond the primary beam.2022A&A...667A..38Ahttps://vo.astron.nl/apertif_dr2/q/apertif_dr2_polarization_cubes/infoSurveyResearchserved-byThe VO @ ASTRON TAP serviceLicensed under CC-BYhttps://vo.astron.nl/apertif_dr2/q/apertif_dr2_polarization_cubes/scs.xml?GETapplication/x-votable+xmlRARight Ascension (ICRS decimal)degpos.eq.rarealDECDeclination (ICRS decimal)degpos.eq.decrealSRSearch radiusdegrealtargetName of the fieldmeta.idcharbeam_numberBeam numbermeta.id;instr.beamintegerobsidObservation idmeta.idchar180100000true342.133.90.001https://vo.astron.nl/apertif_dr2/q/apertif_dr2_polarization_cubes/availabilityhttps://vo.astron.nl/apertif_dr2/q/apertif_dr2_polarization_cubes/capabilitieshttps://vo.astron.nl/apertif_dr2/q/apertif_dr2_polarization_cubes/tableMetadatahttps://vo.astron.nl/tapWSRTApertifRadioapertif_dr2apertif_dr2.pol_cubesaccrefAccess key for the dataAccess.ReferencecharindexednullableownerOwner of the datacharnullableembargoDate the data will become/became publicacharnullablemimeMIME type of the file servedmeta.code.mimeAccess.FormatcharnullableaccsizeSize of the data in bytesbyteVOX:Image_FileSizeAccess.SizelongnullablecenteralphaApproximate center of image, RAdegpos.eq.ra;meta.maindoublenullablecenterdeltaApproximate center of image, Decdegpos.eq.dec;meta.maindoublenullableimagetitleSynthetic name of the imageVOX:Image_TitlecharnullableinstidIdentifier of the originating instrumentINST_IDcharnullabledateobsEpoch at midpoint of observationdVOX:Image_MJDateObsdoublenullablenaxesNumber of axes in dataVOX:Image_NaxesintnullablepixelsizeNumber of pixels along each of the axespixVOX:Image_NaxisintnullablepixelscaleThe pixel scale on each image axisdeg/pixVOX:Image_ScalefloatnullablerefframeCoordinate system reference frameVOX:STC_CoordRefFramecharnullablewcs_equinoxEquinox of the given coordinatesyrVOX:STC_CoordEquinoxfloatnullablewcs_projectionFITS WCS projection typeVOX:WCS_CoordProjectioncharnullablewcs_refpixelWCS reference pixelpixVOX:WCS_CoordRefPixelfloatnullablewcs_refvaluesWorld coordinates at WCS reference pixeldegVOX:WCS_CoordRefValuedoublenullablewcs_cdmatrixFITS WCS CDij matrixdeg/pixVOX:WCS_CDMatrixfloatnullablebandpassidFreeform name of the bandpass usedVOX:BandPass_IDcharnullablebandpassunitUnit of bandpass specifications (always m).VOX:BandPass_UnitcharnullablebandpassrefvalCharacteristic quantity for the bandpass of the imagemVOX:BandPass_RefValuefloatnullablebandpasshiUpper limit of the bandpass (in BandPass_Unit units)mVOX:BandPass_HiLimitfloatnullablebandpassloLower limit of the bandpass (in BandPass_Unit units)mVOX:BandPass_LoLimitfloatnullablepixflagsFlags specifying the processing done (C-original; F-resampled; Z-fluxes valid; X-not resampled; V-for display onlyVOX:Image_PixFlagscharnullablecoverageField covered by the imagedegdoubleindexednullabletargetName of the fieldmeta.idcharnullableobsidUnique idmeta.idcharnullablerelated_productsLink related products for the observationmeta.ref.urlcharnullablevalidWhether or not the dataset has passed validationmeta.code.qualchartask_idID of the taskmeta.idcharnullablebeam_numberNumber of the beammeta.id;instr.beamintfreqminMinimum frequencyMHzem.freqfloatfreqmaxMaximum frequencyMHzem.freqfloatn_channelsNumber of channelsem.binintpub_didDataset identifier assigned by the publishermeta.id;meta.maincharindexednullablepolarizationPolarization Stokesphys.polarization.stokescharnullablesigma_inNoise in inner half degree of the imageuJy/beamstat.errorcharsigma_outNoise at the edge of the residual image, more than a degree from the centreuJy/beamstat.errorcharft_maxMaximum of the absolute of a Fourier Transform of the imagestat.maxcharpeak_innerMaximum of the absolute pixel values in the inner half degree of the imageuJy/beamstat.maxcharbminThe diameter of the FWHM minor axis of the synthesised beamarcsecphys.angsize;instr.beamcharq_beam_fracFraction of Q image planes with beam minor axes less than 17.5’’stat.valuecharu_beam_fracFraction of U image planes with beam minor axes less than 17.5’’stat.valuecharq_noise_fracFraction of Q image planes with rms noise larger than 300 microJy/beamstat.valuecharu_noise_fracFraction of U image planes with rms noise larger than 300 microJy/beamstat.valuecharivoaDefinition and support code for the ObsCore data model and table.ivoa.obscoreThis data collection is queriable in The VO @ ASTRON's obscore table.