J/A+A/436/457ivo://CDS.VizieR/J/A+A/436/457doi:10.26093/cds/vizier.34360457CDSGopal-KrishnaLedoux C.Melnick J.Giraud E.Kulkarni V.Altieri B.2006-12-17T16:38:26Z2006-12-17T17:38:01ZCDS support team

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

cds-question@unistra.frradio-galaxiesgalaxy-classification-systemsinfrared-photometryvisible-astronomybroad-band-photometryWe present the results of radio (VLA) and optical (ESO/La Silla) imaging of a sample of 52 radio sources having an ultra-steep radio spectrum with {alpha} mostly steeper than -1.1 at decimetre wavelengths (median {alpha}=-1.22). Radio-optical overlays are presented to an astrometric accuracy of ~1". For 41 of the sources, radio spectral indices are newly determined using unpublished observations made with the 100-m Effelsberg radio telescope. For 14 of the sources identified with relatively brighter optical counterparts, spectroscopic observations were also carried out at La Silla and their redshifts are found to lie in the range 0.4 to 2.6.2005A&A...436..457Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/436/457CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/93/399 : Optical ID of steep spectrum radio sources (Wieringa+ 1992)J/A+AS/108/79 : Ultra-steep spectrum radiosources (Roettgering+, 1994)J/A+AS/143/303 : Ultra steep spectrum radio sources catalog (De Breuck+ 2000)J/AJ/123/637 : Ultra-steep-spectrum radio sources (De Breuck +, 2002)J/MNRAS/355/20 : K magnitudes of 74MHz radio sources (Jarvis+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/436/457https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/436/457http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/436/457https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/436/457https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/436/457http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/436/457GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/436/457/table1 (Overall properties of the sample galaxies)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/436/457/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/436/457/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/436/457/table1?GETtext/xml+votable180.050000true1.00616676.12527780.0055555555555555566/4299 17408 18159 18167 18637 18649 18654 18660 18783 18818 19505 19520 20886 21078 21157 21162 23069 23168 23236 23318 24918 25079 25435 25662 26113 26120 26815 27045 27382 27484 27692 27826 27905 29031 29352 31367 36180-36181 36184 40357 42996 44370 44372-44373 44627 44693 44714 44816 48844 48851 48899 48949https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/436/457?format=asciiOpticalInfraredRadiodefaultJ/A+A/436/457/table1Overall properties of the sample galaxiesz? Redshiftsrc.redshiftfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIAU name (HHMM+DDd, B1950)meta.id;meta.maincharprimaryn_NameOrigin of the object (1)meta.notecharRAJ2000Right ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (2)pos.eq.dec;meta.mainRMorphRadio morphology (3)meta.code;src.morphcharl_RSize[~<] Limit flag on RSizemeta.code.error;pos.distance;phys.sizecharRSize? Radio sizearcsecphys.angSizeintnullablen_RSize[s] s: see textmeta.notecharalphaRadio spectral indexspect.index;em.radiofloatRFluxRadio flux at 408MHz (or 327MHz if n_RFlux=")")Jyphot.flux.density;em.radio.200-400MHzfloatn_RFlux[)] ): indicates RFlux at 327MHzmeta.notecharFilter[BVRI] Photometric filtermeta.notecharl_mag[=~>] Limit flag on magmeta.code.error;phot.magcharmag? Magnitude in "Filter"magphot.magfloatnullablee_mag? rms uncertainty on magmagstat.error;phot.magfloatnullablen_mag[s] s: see text of the articlemeta.notecharObsDetails of observations (4)meta.codecharJ/A+A/436/457/notesIndividual notesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIAU name (HHMM+DDd, B1950)meta.id;meta.maincharNoteText of the notemeta.notechar