J/AJ/106/426ivo://CDS.VizieR/J/AJ/106/426doi:10.26093/cds/vizier.51060426CDSTYTLER D.FAN X.-M.JUNKKARINEN V.T.COHEN R.D.2023-04-06T16:50:05Z1997-12-09T20:13:53ZCDS support team

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

cds-question@unistra.frquasarsspectroscopyredshiftedWe present Lick Observatory slit spectra of 38 objects which were claimed to have pronounced ultraviolet excess and emission lines. Zhan & Chen (ZC) selected these objects by eye from a UK Schmidt telescope IIIaJ objective prism plate of a field at 0h 0.0deg (l ~= 98 deg, b ~= -60 deg). We concentrate on m(J) ~= 18-19 objects which Zhan and Chen (ZC) thought were most likely to be quasistellar objects (QSOs) at redshift z(em) >= 2.8. Most of our spectra have FWHM spectral resolutions of about 4 A, and relatively high S/N of about 10-50, although some have FWHM ~= 15 A or lower S/N. We find eleven QSOs, four galaxies at z ~= 0.1, twenty-two stars and one unidentified object with a low S/N spectrum. The ZC lists are found to contain many QSOs at low z but few at high z, as expected. Of eleven objects which ZC suggested were QSOs with z(prism) <= 2.8, eight (73%) are QSOs. But only three of twenty-five candidates with z(prism) >= 2.8 are QSOs, and only two (8%) of these are at z >= 2.8. Unfortunately, the ZC prism redshifts are often incorrect: only five of the eleven QSOs are at redshifts similar to z(prism). Six of the QSOs show absorption systems, including Q0000+027A with a relatively strong associated C IV absorption system, and Q0008+008 (V ~= 18.9) with a damped Ly alpha system with an HI column density of 10^21 cm^-2. The stars include a wide variety of spectral types. There is one new DA 4 white dwarf at 170 pc, one sdB at 14 kpc, and three M stars. The rest are of types F, G, and K. We have measured the equivalent widths of the Ca II K line, the G band, and the Balmer lines in ten stars with the best spectra, and we derive metallicities. Seven of them are in the range -2.5 <= [Fe/H] <= -1.7, while the others are less metal poor. If the stars are dwarfs, then they are at distances of 1 to 7 kpc, but if they are giants, typical distances will be about 10 kpc.1993AJ....106..426Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/106/426CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/106/426https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/106/426http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/106/426https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/106/426https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/106/426http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/106/426GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/106/426/table1Journal of observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.maincharObsObservation date, U.T.time.epochInt.timeIntegration timestime.duration;obs.exposureintSetup[ABC] Instrumental setup (see note (1))meta.notecharlamMin[]? Minimum wavelength of the total range (for setup A and B)nmem.wlfloatlamMax[]? Maximun wavelength of the total range (for setup A and B)nmem.wlfloatlambMin[]? Minimum wavelength of the blue range (for setup C)nmem.wlfloatlambMax[]? Maximun wavelength of the blue range (for setup C)nmem.wlfloatlamrMin[]? Minimum wavelength of the red range (for setup C)nmem.wlfloatlamrMax[]? Maximun wavelength of the red range (for setup C)nmem.wlfloatRefZhan and Chen references (2) -------------------------------------------------------------------------------- Note (1) Setup A: 10 object with z =~ 3, observed with the UV Schmidt camera Setup B: 11 intermediate z objects with close neighbours, observed wmeta.refcharJ/AJ/106/426/table2Summary of spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.maincharzOP[]? Objective prism redshift from the ZC references (see table1)src.redshiftfloatq_zOPReliability index Q from the ZC references (see note(1))meta.code.qualintTypeObject type (see note (2))src.classcharSp1Spectral type from the spectral featuressrc.spTypecharSp2Spectral type from (B-V)0src.spTypecharz[]? Redshiftsrc.redshiftfloatu_z[? ] Uncertainty flag on zmeta.code.errorcharlinesSpectral lines -------------------------------------------------------------------------------- Note (1) The reliability index Q = Q1 + Q2, where Q1 is the given value 1, 2, or 3 according to increasing strength of the emission lines, and Q2 is similarlymeta.id;spect.linecharJ/AJ/106/426/table3Magnitudes and spectral indicesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.maincharSetup[AB] Note flag: 'A' for magnitudes measured from Setup A spectrum, and likely to be systematically too faint; 'B' for magnitudes measured from Setup B spectrum.meta.notecharB(J)B(J) magnitude from ZC references, obtained from image sizes on a direct Schmidt plate.magphot.mag;em.opt.BfloatU[]? U magnitude. U is highly uncertainmagphot.mag;em.opt.UfloatBB magnitude. B is highly uncertainmagphot.mag;em.opt.BfloatVV magnitude. V is highly uncertainmagphot.mag;em.opt.Vfloat(B-V)0(B-V)0 color. (B-V)0 is highly uncertainmagphot.color;em.opt.B;em.opt.Vfloat(B-V)[]? (B-V) color estimated from the Balmer line index HP using: (B-V)0 = 0.962 - 0.292HP + 0.036HP^2magphot.color;em.opt.B;em.opt.VfloatDelta[]? Slit (B-V) minus HP index (B-V)magphot.mag;arith.difffloatHP[]? Balmer line index HP, where HP = -0.120 + 0.5Halpha + 0.555Hgamma, which is the average of the measured equivalent width of Halpha, and an estimate of that width based on the measured equivalent width of Hgamma.0.1nmspect.indexfloatKP[]? Index KP', the Ca II K equivalent width measured in the 18 A interval, corrected for interstellar Ca II K absorption by subtracting 0.22 A.0.1nmspect.line.eqWidthfloatGP[]? G-band (CH) index, GP, the equivalent width in the 15 A band around 4300 A.0.1nmspect.line.eqWidthfloatJ/AJ/106/426/table5Emission linesu_lamLabUncertainty flag on lamLabmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.mainchar<z(em)>[]? Mean emission redshiftsrc.redshiftfloatIonIonphys.atmol.ionizationcharlamLabLaboratory vacuum wavelength0.1nmem.wl;phys.atmol.transitionfloatlamObsObserved wavelength0.1nmem.wlfloatEWobsObserved frame equivalent width. All values have a decimal point, so that they will be read correctly by a computer program, but some of the values were originally integers0.1nmspect.line.eqWidthfloatz(em)Emission redshiftsrc.redshiftfloatComComments. The comment 'see notes' refers to file notesmeta.notecharJ/AJ/106/426/table6Major absorption lines in the QSO spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.maincharNoSequential number counting the line for this objectmeta.idintWObs[]? Observed vacuum wavelength0.1nmem.wlfloatn_WObs[d] When 'd', it means that the line was seen by reference ZC2 (see table1 description)meta.notecharEWobs[]? Observed equivalent width0.1nmspect.line.eqWidthfloatIdentLine identificationmeta.idcharWLab[]? Laboratory wavelengthnmem.wl;phys.atmol.transitionfloatn_WLab[bc ] Note flags: 'b' Blended with C IV (1550 A) 'c' see notes filemeta.notecharz(abs)[]? Absorption redshiftsrc.redshiftfloat