J/A+A/678/A72ivo://CDS.VizieR/J/A+A/678/A72doi:10.26093/cds/vizier.36780072CDSDokara R.Roy N.Menten K.Vig S.Dutta P.Beuther H.Pandian J.D.,Rugel M.Rashid M.Brunthaler A.2025-05-22T20:01:29Z2023-10-06T07:43:42ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyradio-continuum-emissioninterferometryThe advent of wide-band receiver systems on interferometer arrays enables one to undertake high-sensitivity and high-resolution radio continuum surveys of the Galactic plane in a reasonable amount of telescope time. However, to date, there are only a few such studies of the first quadrant of the Milky Way that have been carried out at frequencies below 1 GHz. The Giant Metrewave Radio Telescope (GMRT) has recently upgraded its receivers with wide-band capabilities (now called the uGMRT) and provides a good opportunity to conduct high resolution surveys, while also being sensitive to the extended structures. We wish to assess the feasibility of conducting a large-scale snapshot survey, the Metrewave Galactic Plane with the uGMRT Survey (MeGaPluG), to simultaneously map extended sources and compact objects at an angular resolution lower than 10'' and a point source sensitivity of 0.15mJy/beam. We performed an unbiased survey of a small portion of the Galactic plane, covering the W43/W44 regions (l=29{deg}-35{deg} and |b|<1{deg}) in two frequency bands: 300-500MHz and 550-750MHz. The 200MHz wide-band receivers on the uGMRT are employed to observe the target field in several pointings, spending nearly 14 minutes on each pointing in two separate scans. We developed an automated pipeline for the calibration, and a semi-automated self-calibration procedure is used to image each pointing using multi-scale CLEAN and outlier fields. We produced continuum mosaics of the surveyed region at a final common resolution of 25'' in the two bands that have central frequencies of 400MHz and 650MHz, with a point source sensitivity better than 5mJy/beam. A spectral index map is also obtained, which is helpful to distinguish between thermal and nonthermal emission. Comparing with other surveys, we validated the positions and flux densities obtained from our data. We plan to cover a larger footprint of the Galactic plane in the near future based on the lessons learnt from this study.2023A&A...678A..72Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A72CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/678/A72https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/678/A72http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/678/A72https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/678/A72https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/678/A72http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/678/A72GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/678/A72/list (List of fits maps)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A72/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A72/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A72/list?GETtext/xml+votable180.050000true282.7560348-0.20302350.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/678/A726/30312https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/678/A72?format=asciiRadiodefaultJ/A+A/678/A72/listList of fits mapssizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.raindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGLONGalactic longitude of center (J2000)degpos.galactic.lonGLATGalactic latitude of center (J2000)degpos.galactic.latNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullablelambdaObserved wavelengthmem.wlfloatTitleTitle of the FITS filemeta.title;meta.fitschar