J/MNRAS/395/269ivo://CDS.VizieR/J/MNRAS/395/269doi:10.26093/cds/vizier.73950269CDSSirothia S.K.Dennefeld M.Saikia D.J.Dole H.Ricquebourg F.,Roland J.2024-07-08T20:15:48Z2010-09-30T15:16:49ZCDS support team

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

cds-question@unistra.frsurveysradio-galaxiesWe present observations of the European Large-Area ISO Survey-North 1 (ELAIS-N1) at 325MHz using the Giant Metrewave Radio Telescope (GMRT), with the ultimate objective of identifying active galactic nuclei and starburst galaxies and examining their evolution with cosmic epoch. After combining the data from two different days we have achieved a median rms noise of ~40uJy/beam, which is the lowest that has been achieved at this frequency. We detect 1286 sources with a total flux density above ~270uJy. In this paper, we use our deep radio image to examine the spectral indices of these sources by comparing our flux density estimates with those of Garn et al. 2008 (Cat. J/MNRAS/383/75) at 610MHz with the GMRT, and surveys with the Very Large Array at 1400MHz. We attempt to identify very steep spectrum sources which are likely to be either relic sources or high-redshift objects as well as inverted-spectra objects which could be Giga-Hertz Peaked Spectrum objects. We present the source counts, and report the possibility of a flattening in the normalized differential counts at low flux densities which has so far been reported at higher radio frequencies.2009MNRAS.395..269Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/395/269CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/255 : SWIRE ELAIS N1 Source Catalogs (Surace+, 2004)J/AJ/129/1198 : SDSS quasars in SWIRE ELAIS N1 field (Hatziminaoglou+, 2005)J/MNRAS/371/1891 : GOODS ELAIS-N1 24um flux densities (Rodighiero+, 2006)J/ApJ/666/201 : Radio polarimetry of the ELAIS N1 field (Taylor+, 2007)J/MNRAS/383/75 : Deep 610MHz survey of ELAIS-N1 sources (Garn+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/395/269https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/395/269http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/395/269https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/395/269https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/395/269http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/395/269GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/395/269/table3 (The source catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/395/269/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/395/269/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/395/269/table3?GETtext/xml+votable180.050000true240.63666754.9019170.0055555555555555565/2538 6/10147 10150 10156 10158 11520-115212.1534725313611987e-25 2.1534725313611987e-25https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/395/269?format=asciiRadiodefaultJ/MNRAS/395/269/table3The source catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGMRTGMRT source name (HHMMSS+DDMMSS), [SDS2009] GMRT JHHMMSS+DDMMSS in Simbadmeta.id;meta.maincharRAJ2000Right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)pos.eq.dec;meta.mainDistDistance of the centroid from the phase centerdegpos.angDistancefloatrmsLocal rms noise value (in {mu}Jy/beam)uJystat.stdev;instr.det.noiseintSp325MHz peak flux density (in mJy/beam)mJyphot.flux.density;em.radio.200-400MHzfloatStot3325MHz total flux density within the 3{sigma} contourmJyphot.flux.density;em.radio.200-400MHzfloatStot325MHz total flux densitymJyphot.flux.density;em.radio.200-400MHzfloatSize? Largest angular size for resolved sourcearcsecphys.angSize;stat.maxfloatnullableNote[U] U for unresolved sourcemeta.notechar