J/MNRAS/375/1349ivo://CDS.VizieR/J/MNRAS/375/1349doi:10.26093/cds/vizier.73751349CDSCruz M.J.Jarvis M.J.Rawlings S.Blundell K.M.2024-07-04T20:17:51Z2008-01-23T07:30:01ZCDS support team

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

cds-question@unistra.frradio-sourcesredshiftedWe use the 6C** sample to investigate the comoving space density of powerful, steep-spectrum radio sources. This sample, consisting of 68 objects, has virtually complete K-band photometry and spectroscopic redshifts for 32 per cent of the sources. In order to find its complete redshift distribution, we develop a method of redshift estimation based on the Kz diagram of the 3CRR, 6CE, 6C* and 7CRS radio galaxies. Based on this method, we derive redshift probability density functions for all the optically identified sources in the 6C** sample. Using a combination of spectroscopic and estimated redshifts, we select the most radio luminous sources in the sample. Their redshift distribution is then compared with the predictions of the radio luminosity function of Jarvis et al. (2001MNRAS.327..907J). We find that, within the uncertainties associated with the estimation method, the data are consistent with a constant comoving space density of steep-spectrum radio sources beyond z>2.5, and rule out a steep decline.2007MNRAS.375.1349Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/375/1349CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/18 : 6C Survey of radio sources - I. (Baldwin+ 1985)VIII/21 : 6C Survey of radio sources - II. (Hales+ 1988)VIII/22 : 6C Survey of Radio Sources - III. (Hales+ 1990)VIII/23 : 6C Survey of radio sources - IV. (Hales+ 1991)VIII/24 : 6C Survey of Radio Sources - V. (Hales+ 1993)VIII/25 : 6C Survey of radio sources - VI. (Hales+ 1993)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)J/MNRAS/373/1531 : 6C** sample of steep-spectrum radio sources (Cruz+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/375/1349https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/375/1349http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/375/1349https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/375/1349https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/375/1349http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/375/1349GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/375/1349/table1 (Summary of the observational data on the 6C** sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/375/1349/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/375/1349/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/375/1349/table1?GETtext/xml+votable180.050000true109.49291746.190.0055555555555555566/5070 5108 5335 5345 5439 5444 5534 5547 5554 5556-5557 5560 5562 5624 5682 5693 5707 5713 5722 5745 5753 5771 5784-5786 5789 5803 5805 5846 5848 5867 5903 5937 5985 5991-5992 6037 6052 6090 6359 6449 6473 6479 6515 6605 6625 6640 6648 6926 6941 6965 6998 7007 7168 7171 7204 7206-7207 7232 7246 7259 7281 7311 7322 28594 28598 28641https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/375/1349?format=asciiOpticalRadiodefaultJ/MNRAS/375/1349/table1Summary of the observational data on the 6C** samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint6CSource name, 6CHHMM+DDMM (B1950)meta.id;meta.maincharS151MHz151MHz flux-density measurements (1)Jyphot.flux.density;em.radio.100-200MHzfloatSIradio spectral index evaluated between 151MHz and 1.4GHz (2)spect.index;em.radio.100-200MHzfloatl_KmagLimit flag on Kmagmeta.code.errorcharKmagKmagnitudemagphot.mag;em.IR.KfloatAperAngular aperture used for Kmagphys.angSize;instr.fovintz? Redshiftsrc.redshiftfloatnullableu_z[?] Uncertainty flag on zmeta.code.error;src.redshiftcharn_z[nd ] no detection (3)meta.notecharr_zReference for the redshift (5)meta.ref;pos.framechareLineProminent emission line in the existing spectra (4)meta.id;spect.linecharLum? Luminosity of the emission line eLinelog(W)phys.luminosityfloatnullablePapIPapI: Display the data of paper I, J/MNRAS/373/1531meta.ref.urlcharSpRadio spectrum from SPECFINDmeta.ref.urlchar_RAPositions (from paper I, J/MNRAS/373/1531) (right ascension part)degpos.eq.ra;meta.main_DEPositions (from paper I, J/MNRAS/373/1531) (declination part)degpos.eq.dec;meta.main