J/MNRAS/348/857ivo://CDS.VizieR/J/MNRAS/348/857doi:10.26093/cds/vizier.73480857CDSHolt J.Benn C.R.Vigotti M.Pedani M.Carballo R.,Gonzalez-serrano J.I.Mack K.-H.Garcia B.2024-06-29T20:14:45Z2004-10-16T15:46:11ZCDS support team

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

cds-question@unistra.frquasarsredshiftedphotometryradio-astronomyspectroscopyWe obtained spectra of 60 red, star-like objects (m_E_<18.8) identified with FIRST radio sources, S_1.4GHz_>1mJy. Eight are quasi-stellar objects (QSOs) with redshift z>3.6. Combined with our earlier pilot search, our sample of 121 candidates yields a total of 18 z>3.6 QSOs (10 of these with z>4.0). 8 per cent of candidates with S_1.4GHz_<10mJy and 37 per cent of candidates with S_1.4GHz_>10mJy are QSOs with z>3.6. The surface density of m_E_<18.8, S_1.4GHz_>1mJy, z>4 QSOs is 0.003deg^-2^. This is currently the only well-defined sample of radio-loud QSOs at z~4 selected independently of radio spectral index. The QSOs are highly luminous in the optical (eight have M_B_<28, q_0_=0.5, H_0_=50km/s/Mpc). The SEDs are as varied as those seen in optical searches for high-redshift QSOs, but the fraction of objects with weak (strongly self-absorbed) Ly emission is marginally higher (3 out of 18) than for high-redshift QSOs from SDSS (5 out of 96).2004MNRAS.348..857Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/348/857CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)J/ApJS/143/1 : FIRST-APM Source Catalog (McMahon+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/348/857https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/348/857http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/348/857https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/348/857https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/348/857http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/348/857GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/348/857/table1 (High-redshift radio QSOs in FIRST (<VIII/71>))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/348/857/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/348/857/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/348/857/table1?GETtext/xml+votable180.050000true139.60158336.61486110.005555555555555556Cone search capability for table J/MNRAS/348/857/table2 (Candidates which are not z>3.6 QSOs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/348/857/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/348/857/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/348/857/table2?GETtext/xml+votable180.050000true133.4027517.72997220.0055555555555555566/4112 4168 4196 4310 4336 4347 4394 4436 4472 4484 5354 5563 5669 6061 6219 6386 7248 7301 7309 8264 8303 8336 8448 8469 8595 8635 8837 8890 8900 8903 8925 9191 9252 9464 9988 10035 10291 10568 10658 10846 10861 10946 11130 11200 11290 11392 25918 25949 25993 26060 26141 26184 26195 26213 26222 26238 26260 26568 26619 27023 27077 27190 27243 27379 27524 27544 27763 27833 27859 27866 28171 28205 28482 28527 28609 31291 31696 32409 32416https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/348/857?format=asciiOpticalRadiodefaultJ/MNRAS/348/857/table1High-redshift radio QSOs in FIRST (<VIII/71>)dR-ORadio-optical position differencearcsecpos.angDistancefloatEmagAPM POSS-I E magnitudemagphot.mag;em.opt.Rfloatl_O-ELimit flag on O-Emeta.code.errorcharO-EAPM POSS-I O-E colourmagphot.color;em.opt.B;em.opt.RfloatRmag? JKT (Jacobus Kapteyn Telescope) R magnitudemagphot.mag;em.opt.RfloatnullableImag? JKT (Jacobus Kapteyn Telescope) I magnitudemagphot.mag;em.opt.IfloatnullablezRedshiftsrc.redshiftfloate_zrms error on redshiftstat.errorfloatl_EWLya+NVLimit flag on EWLya+NVmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSample[ABC] Sample designation (1)meta.idcharRAJ2000Optical right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainS1.4GHz? FIRST 1.4GHz flux density (integrated for S1.4GHz>10mJy, otherwise peak)mJyphot.flux.density;em.radio.750-1500MHzfloatnullableS4.85GHz? Integrated Effelsberg 4.85GHz flux densitymJyphot.flux.density;em.radio.3-6GHzfloatnullableS10.6GHz? Integrated Effelsberg 10.6GHz flux densitymJyphot.flux.density;em.radio.6-12GHzfloatnullableSp+Index? Radio spectral index alphaspect.indexfloatnullablelogLRRadio luminosity (2)log(W.Hz**-1)phys.luminosityfloatEWLya+NV? Approximate rest-frame Ly{alpha}+NV equivalent width, +/-30%nmspect.line.eqWidthfloatnullableu_EWLya+NV[?] Uncertainty flag on EWLya+NVmeta.code.errorcharDAContinuum decrement across Ly{alpha} line (Section 4.1.2 of the paper)spect.line.widthfloatNotesNotesmeta.notecharFIRSTShow FIRST datameta.refcharJ/MNRAS/348/857/table2Candidates which are not z>3.6 QSOsEmagAPM POSS-I E magnitudemagphot.mag;em.opt.RfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSample[QS] Samples (1)meta.idcharRAJ2000Optical right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainS1.4GHz? FIRST 1.4GHz flux density (integrated, for S_1.4GHz_>10mJy, otherwise peak)mJyphot.flux.density;em.radio.750-1500MHzfloatnullabledR-ORadio-optical position differencearcsecpos.angDistancefloatl_O-ELimit flag on O-Emeta.code.errorcharO-EAPM POSS-I O-E colourmagphot.color;em.opt.B;em.opt.RfloatType[QGS?*] Type of object (Q = QSO, G = Galaxy, ? = probable galaxy, * = star, S not explained)src.classcharz? Redshiftsrc.redshiftfloatnullablee_z? rms error on redshiftstat.errorfloatnullableNotesNotesmeta.notecharFIRSTShow FIRST datameta.refchar