J/MNRAS/544/321ivo://CDS.VizieR/J/MNRAS/544/321doi:10.26093/cds/vizier/bg-h0-a1CDSElahi K.M.A.Choudhuri S.Roy N.Rashid M.Bull P.Vir Lal D.2026-08-03T07:33:40Z2025-10-30T12:08:49ZCDS support team

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

cds-question@unistra.frsurveysradio-continuum-emissiongalaxiescatalogsradio-sourcesRadio-interferometric arrays require very precise calibration to detect the Epoch of Reionization 21-cm signal. A remarkably complete and accurate sky model is therefore needed in the patches of the sky used to perform the calibration. Instruments such as HERA, which use a redundant calibration strategy, also require a reference sky model to fix degenerate gain solutions. We have carried out a deep (20 hours) observation using the upgraded GMRT to make a high-fidelity sky model of one of the HERA calibration fields, GLEAM 02H (J0200-3053). In this paper, we present the results from a 16.7MHz bandwidth dataset centred at 147.4MHz. Multiple GMRT pointings are combined to make a 6.9degx6.9deg mosaic, yielding a median rms of 3.9^+3.7^_-1.4_mJy/beam, which reduces to approximately 2mJy/beam in source-free regions. In the overlapping patch, this rms is deeper than the GLEAM catalogue, which is used for HERA calibration. Using the mosaic, we have made a catalogue of 640 sources (26% extended) with flux densities in the range 0.02-19.08Jy. The catalogue has sub-arcsecond positional accuracy, and the estimated fluxes are consistent with existing catalogues. The differential source counts are deeper than GLEAM and consistent with LoTSS. A preliminary simulation comparing the sky models from GLEAM and our catalogue shows 10-25% differences in the visibility amplitude, with a relatively small change of approximately 2 degrees in phases. Future work is planned for larger survey areas and wider bandwidths to reduce the rms and measure in-band source spectral indices, which are expected to enhance the fidelity of the HERA calibration model.2025MNRAS.544..321Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/544/321CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/544/321https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/544/321http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/544/321https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/544/321https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/544/321http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/544/321GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/544/321/gmrt2hss (uGMRT 147 MHz catalogue around PKS 0157-31)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/544/321/gmrt2hss?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/544/321/gmrt2hss?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/544/321/gmrt2hss?GETtext/xml+votable180.050000true33.91097674032-30.797724379850.005555555555555556Cone search capability for table J/MNRAS/544/321/list (Information on fits image)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/544/321/list?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/544/321/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/544/321/list?GETtext/xml+votable180.050000true30.05127-30.89440.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/MNRAS/544/3214/2229 5/8830-8831 8913 8915 8924 6/35309-35311 35649 35651 35657 35659 35681 35684-35685 35687 35700-35702 36354 36360 363629.740322260453885e-26 9.740322260453885e-26https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/544/321?format=asciiRadiodefaultJ/MNRAS/544/321/gmrt2hssuGMRT 147 MHz catalogue around PKS 0157-31IslmeanMean flux in the island (Isl_mean)Jy/beamphot.flux.density;em.radio.100-200MHzdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource identification number (Source_id)meta.id;meta.mainintIslIsland identification number (Isl_id)meta.id.parentintRAJ2000Right Ascension (J2000) (RA)degpos.eq.ra;meta.maine_RAJ2000Uncertainty in RA (E_RA)degstat.error;pos.eq.radoubleDEJ2000Declination (J2000) (DEC)degpos.eq.dec;meta.maine_DEJ2000Uncertainty in DEC (E_DEC)degstat.error;pos.eq.decdoubleFluxTotIntegrated flux density at 147MHz (Total_flux)Jyphot.flux.density;em.radio.100-200MHzdoublee_FluxTotError in integrated flux density at 147MHz (E_Total_flux)Jystat.errordoubleFluxPPeak flux density at 147MHz (Peak_flux)Jy/beamphot.flux.density;em.radio.100-200MHzdoublee_FluxPError in peak flux density at 147MHz (E_Peak_flux)Jy/beamstat.errordoubleRAMdegRight Ascension (J2000) of maximum pixel (RA_max)degpos.eq.rae_RAMdegError in RA_max (E_RA_max)degstat.errordoubleDEMdegDeclination (J2000) of maximum pixel (DEC_max)degpos.eq.dece_DEMdegError in DEC_max (E_DEC_max)degstat.errordoubleMajFitted major axis (deconvolved) (Maj)degphys.angSize;meta.modelleddoublee_MajError in major axis (E_Maj)degstat.errordoubleMinFitted minor axis (deconvolved) (Min)degphys.angSize;meta.modelleddoublee_MinError in minor axis (E_Min)degstat.error;stat.mindoublePAPosition angle (deconvolved) (PA)degpos.posAngdoublee_PAError in position angle (E_PA)degstat.errordoubleMajimgplaneFitted major axis (image plane) (Maj_img_plane)degphys.angSize;meta.modelleddoublee_MajimgplaneError in major axis (image plane) (E_Maj_img_plane)degstat.errordoubleMinimgplaneFitted minor axis (image plane) (Min_img_plane)degphys.angSize;meta.modelleddoublee_MinimgplaneError in minor axis (image plane) (E_Min_img_plane)degstat.errordoublePAimgplanePosition angle (image plane) (PA_img_plane)degpos.posAngdoublee_PAimgplaneError in PA (image plane) (E_PA_img_plane)degstat.errordoubleDCMaj? Deconvolved major axis (corrected) (DC_Maj)degphys.angSizedoublenullablee_DCMaj? Error in DC_Maj (E_DC_Maj)degstat.errordoublenullableDCMin? Deconvolved minor axis (corrected) (DC_Min)degphys.angSizedoublenullablee_DCMin? Error in DC_Min (E_DC_Min)degstat.errorfloatnullableDCPA? Deconvolved position angle (DC_PA)degpos.posAngdoublenullablee_DCPA? Error in DC_PA (E_DC_PA)degstat.errorfloatnullableDCMajimgplane? Deconvolved major axis (image plane) (DC_Maj_img_plane)degphys.angSizedoublenullablee_DCMajimgplane? Error in DC_Maj_img_plane (E_DC_Maj_img_plane)degstat.errordoublenullableDCMinimgplane? Deconvolved minor axis (image plane) (DC_Min_img_plane)degphys.angSizedoublenullablee_DCMinimgplane? Error in DC_Min_img_plane (E_DC_Min_img_plane)degstat.errordoublenullableDCPAimgplane? Deconvolved PA (image plane) (DC_PA_img_plane)degpos.posAngdoublenullablee_DCPAimgplane? Error in DC_PA_img_plane (E_DC_PA_img_plane)degstat.errordoublenullableFluxIslIsland total flux density at 147MHz (Isl_Total_flux)Jyphot.flux.density;em.radio.100-200MHzdoublee_FluxIslError in island total flux at 147MHz (E_Isl_Total_flux)Jystat.errordoubleIslrmsLocal rms in the island (Isl_rms)Jy/beamstat.errordoubleResidIslrmsResidual rms in the island at 147MHz (Resid_Isl_rms)Jy/beamstat.errordoubleResidIslmeanResidual mean in the island at 147MHz (Resid_Isl_mean)Jy/beamphot.flux.density;em.radio.100-200MHzdoubleSCode[CMS] S_Code (1)meta.codecharJ/MNRAS/544/321/listInformation on fits imagerecnoRecord 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.freqfloatsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar