J/ApJ/950/95ivo://CDS.VizieR/J/ApJ/950/95CDSMatthews B.M.Dix C.Shemmer O.Brotherton M.S.Myers A.D.,Andruchow I.Brandt W.N.Gallagher S.C.Green R.Lira P.McLane J.N.,Plotkin R.M.Richards G.T.Runnoe J.C.Schneider D.P.Strauss M.A.2025-10-01T06:29:29Z2025-09-04T11:54:41ZCDS support team

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

cds-question@unistra.frquasarsinfrared-astronomyspectroscopysurveysredshiftedline-intensitiesactive-galactic-nucleivisible-astronomyQuasars at z>~1 most often have redshifts measured from rest-frame ultraviolet emission lines. One of the most common such lines, CIV{lambda}1549, shows blueshifts up to ~5000km/s and in rare cases even higher. This blueshifting results in highly uncertain redshifts when compared to redshift determinations from rest-frame optical emission lines, e.g., from the narrow [OIII]{lambda}5007 feature. We present spectroscopic measurements for 260 sources at 1.55<~z<~3.50 having -28.0<~M_i_<~-30.0mag from the Gemini Near Infrared Spectrograph-Distant Quasar Survey (GNIRS-DQS) catalog, augmenting the previous iteration, which contained 226 of the 260 sources whose measurements are improved upon in this work. We obtain reliable systemic redshifts based on [OIII]{lambda}5007 for a subset of 121 sources, which we use to calibrate prescriptions for correcting UV-based redshifts. These prescriptions are based on a regression analysis involving CIV full-width-at-half-maximum intensity and equivalent width, along with the UV continuum luminosity at a rest-frame wavelength of 1350{AA}. Applying these corrections can improve the accuracy and the precision in the CIV-based redshift by up to ~850km/s and ~150km/s, respectively, which correspond to ~8.5 and ~1.5Mpc in comoving distance at z=2.5. Our prescriptions also improve the accuracy of the best available multifeature redshift determination algorithm by ~100km/s, indicating that the spectroscopic properties of the CIV emission line can provide robust redshift estimates for high-redshift quasars. We discuss the prospects of our prescriptions for cosmological and quasar studies utilizing upcoming large spectroscopic surveys.2023ApJ...950...95Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/950/95CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)VII/286 : SDSS quasar catalog, fourteenth data release (Paris+, 2018)VII/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)J/AJ/130/381 : Blueshifted [O III] emission (Boroson+, 2005)J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)J/ApJ/666/757 : CIV 1549{AA} emission line in AGNs (Sulentic+, 2007)J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008)J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)J/ApJ/726/20 : X-ray emission from quasars (Miller+, 2011)J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)J/ApJ/831/7 : SDSS-RM project: peak velocities of QSOs (Shen+, 2016)J/MNRAS/465/2120 : Correcting CIV-based virial BH masses (Coatman+, 2017)J/ApJ/887/196 : REQUIEM survey. I. Lya halos around QSOs (Farina+, 2019)J/MNRAS/487/3305 : Broad-line velocity shifts in 1.5<z<7.5 QSOs (Meyer+, 2019)J/ApJ/903/112 : SDSS Hb & CIV reverberation mapped AGNs (Dalla Bonta+, 2020)J/ApJ/905/51 : X-SHOOTER/ALMA QSOs at 5.78<z<7.54. I. (Schindler+, 2020)J/ApJS/252/15 : GNIRS-Distant Quasar Survey (GNIRS-DQS) (Matthews+, 2021)http://datalab.noirlab.edu/data/gemini-llps/gnirs-dqs : GNIRS-DQS (Geminihttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/950/95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/950/95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/950/95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/950/95https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/950/95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/950/95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/950/95/table1 (The Gemini Near Infrared Spectrograph--Distant Quasar Survey (GNIRS-DQS) observation log)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/950/95/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/950/95/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/950/95/table1?GETtext/xml+votable180.050000true1.4363061-4.82090830.0055555555555555566/526 642 2089 2282 2571 4099 4139 4155 4164 4224 4273 4299 4343 4367 4406 4451 4459 4483 4503 4524 4534 4579 4596 4604 4617 4630 4639 4648 4657 4665 4686 4699 4790 4844-4845 4856 4888 4891 4930 4977 5056 5065 5087 5094 5128 5133 5163 5205 5227 5269 5303 5318 5335 5344 5350 5366 5402 5470 5486 5551 5555 5637 5641 5651 5657 5661 5692 5698 5723 5793-5794 5803-5804 5819-5820 5845 5879 5902 5914 5937-5938 5950 6038 6053 6070 6106 6112 6131 6143 6168 6192 6210 6220 6403 6415 6419 6421 6428 6432-6433 6495 6577 6587 6598 6604 6639 6648 6652 6915 6930 6976 7199 7208 7232 7252 7304 7313 7324 7399 7408 7432 7485 7500 7529 7553 7609 8262 8392 8404 8416 8445 8523-8524 8527 8549 8592 8674 8709 8740 8784 8799 8839 8923 8942 8947 8954 8965 9120 9187 9268 9282 9286 9359 9365 9401 9403 9410 9418 9454 9759 9773 9785 9800 9912 10011 10074 10148 10269 10331 10474 10601 10706 10717 10919 10957-10958 10976 10996 10999 11082 11084 11140 11281 11294 11358-11359 11429 11486 11553 12625 12756 13351 13574 17257 17317 17368 17500 17550 17607 17725 17756 17783 17824 17832 17987 18043 18055 18076 18081 18113 18115-18117 18149 18192 18207 18239 18334 18341 18352 18375 18381 18416 18769 18851 18865 18944 18948 18998 19106 19110 19290 19384 19558 19766 19813 19817 19842 20031 20057 20205 20295 20320-20321 20366 20439 21782 21983 22013 22359 22367 23058 25953 25955 26103 26254 26298 26382 26453 26532 26567 26972 26992 27080 27118 27197 27206 27251 27342 27360 27426 27430 27460 27574 27578 27588 27745 27794 27884 27908 28034 28096 28160 28162 28174 28181 28251 28283 28316 28365 28382 28436 28456 28473 28507 28538 28572 28604 28634 28651 31740 32397 32641 45046 45049 48989 49100 491068.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/950/95?format=asciiOpticalInfrareddefaultJ/ApJ/950/95/table1The Gemini Near Infrared Spectrograph--Distant Quasar Survey (GNIRS-DQS) observation logrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVelDisplay the redshift and velocity offsets (Table 5)meta.ref.urlintnullableSDSSSDSS DR16 object designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharprimarym_SDSSNumber of observations for this sourcemeta.numberintnullablezSDSS[1.55/3.54] SDSS spectroscopic redshift (1)src.redshift;pos.heliocentricfloatJmag[14.88/17.6] 2MASS J band magnitudemagphot.mag;em.IR.JfloatNEDNED column added by the CDSmeta.ref.urlcharHmag[14/16.5] 2MASS H band magnitudemagphot.mag;em.IR.HfloatKsmag[13.5/16.7] 2MASS Ks band magnitudemagphot.mag;em.IR.KfloatObsDateObservation date (UT)'Y:M:D'time.epoch;obsnullableSemIDSemester of observationmeta.id;obscharNExp[450/2350] Net exposure timestime.duration;obs.exposure;src.netintComm[0/3]? Additional comment code (2)meta.codeintnullableBAL[0/1] Broad Absorption Line quasar (1=78 occurrences)meta.codeintRL[0/1] Radio-Loud quasar (1=15 occurrences)meta.noteintPapIIDisplay data from Paper II (Dix+ 2023, J/ApJ/950/96)meta.ref.urlintnullableM21Display data from Matthews+ 2021, J/ApJS/252/15meta.ref.urlintnullablespGDisplay the spectral measurements (Tables 2+4)meta.ref.urlintnullableSupDisplay the supplemental emission-line measurements (Table 3)meta.ref.urlintnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/ApJ/950/95/spdataSpectral measurements (Table 2) and Gaussian parameters of emission-line profiles (Table 4)e_LC-Hb[1/49] Lower uncertainty in LC-Hb0.1nmstat.error;stat.min;em.wlintFWHM-Hb[1705/12197] Hbeta emission line FWHMkm/sspect.line.width;em.line.Hbetaintn-STD-O31[5/78]? Width of the narrow [OIII] 4959A Gaussian profile0.1nmspect.line.widthintnullableSDSSSDSS object designation (JHHMMSS.ss+DDMMSS.s) as in Table 1; column added by CDSmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSDSS object designation (JHHMMSS.ss+DDMMSS.s)meta.idcharzSys[1.54/3.54] Systemic redshiftsrc.redshiftfloatn_zSysEmission line source for the systemic redshift (O3, Hb or Mg2)meta.id;spect.linecharLC-Mg2[8678/12709]? Mg II observed-frame wavelength (1)0.1nmem.wlintnullableE_LC-Mg2[1/17]? Upper uncertainty in LC-Mg20.1nmstat.error;stat.max;em.wlintnullablee_LC-Mg2[1/22]? Lower uncertainty in LC-Mg20.1nmstat.error;stat.min;em.wlintnullableFWHM-Mg2[1967/6096]? Mg II emission line FWHMkm/sspect.line.widthintnullableE_FWHM-Mg2[59/1524]? Upper uncertainty in FWHM-Mg2km/sstat.error;stat.max;spect.line.widthintnullablee_FWHM-Mg2[78/2017]? Lower uncertainty in FWHM-Mg2km/sstat.error;stat.min;spect.line.widthintnullableEW-Mg2[9/53]? Rest-frame Mg II emission line equivalent width0.1nmspect.line.eqWidthintnullableE_EW-Mg2[1/31]? Upper uncertainty in EW-Mg20.1nmstat.error;stat.max;spect.line.eqWidthintnullablee_EW-Mg2[1/31]? Lower uncertainty in EW-Mg20.1nmstat.error;stat.min;spect.line.eqWidthintnullableAS-Mg2[-1.1/0.9]? Asymmetry of Mg II double Gaussian fit profile (2)stat.fit.paramdoublenullableKURT-Mg2[2/5.1]? Kurtosis of Mg II double Gaussian fit profile (3)stat.fit.paramfloatnullableLC-Hb[12386/22075] Hbeta observed-frame wavelength (1)0.1nmem.wl;em.line.HbetaintE_LC-Hb[1/37] Upper uncertainty in LC-Hb0.1nmstat.error;stat.max;em.wlintE_FWHM-Hb[1/13599] Upper uncertainty in FWHM-Hbkm/sstat.error;stat.max;spect.line.widthinte_FWHM-Hb[1/8981] Lower uncertainty in FWHM-Hbkm/sstat.error;stat.min;spect.line.widthintEW-Hb[13/128] Rest-frame Hbeta emission line equivalent width0.1nmspect.line.eqWidth;em.line.HbetaintE_EW-Hb[1/57] Upper uncertainty in EW-Hb0.1nmstat.error;stat.max;spect.line.eqWidthinte_EW-Hb[1/76] Lower uncertainty in EW-Hb0.1nmstat.error;stat.min;spect.line.eqWidthintAS-HbJ/ApJ/950/95/table3Column headings for supplemental emission-Line measurementse_LC-Hg[1/12]? Lower uncertainty in LC-Hg0.1nmstat.error;stat.min;em.wlintnullableFWHM-Hg[1164/7490]? Hgamma emission line FWHMkm/sspect.line.width;em.line.HgammaintnullableE_FWHM-Hg[16/8496]? Upper uncertainty in FWHM-Hgkm/sstat.error;stat.max;spect.line.widthintnullablee_FWHM-Hg[21/1920]? Lower uncertainty in FWHM-Hgkm/sstat.error;stat.min;spect.line.widthintnullableEW-Hg[2/58]? Rest-frame Hgamma emission line equivalent width (2)0.1nmspect.line.eqWidth;em.line.HgammaintnullableSDSSSDSS object designation (JHHMMSS.ss+DDMMSS.s) as in Table 1; column added by CDSmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSDSS object designation (JHHMMSS.ss+DDMMSS.s)meta.idcharLC-Hd[11832/12614]? Hdelta observed-frame wavelength (1)0.1nmem.wl;em.line.HdeltaintnullableE_LC-Hd[1/4]? Upper uncertainty in LC-Hd0.1nmstat.error;stat.max;em.wlintnullablee_LC-Hd[1/5]? Lower uncertainty in LC-Hd0.1nmstat.error;stat.min;em.wlintnullableFWHM-Hd[721/1080]? Hdelta emission line FWHMkm/sspect.line.width;em.line.HdeltaintnullableE_FWHM-Hd[31/682]? Upper uncertainty in FWHM-Hdkm/sstat.error;stat.max;spect.line.widthintnullablee_FWHM-Hd[42/721]? Lower uncertainty in FWHM-Hdkm/sstat.error;stat.min;spect.line.widthintnullableEW-Hd[3/12]? Rest-frame Hdelta emission line equivalent width0.1nmspect.line.eqWidth;em.line.HdeltaintnullableE_EW-Hd[1/1]? Upper uncertainty in EW-Hd0.1nmstat.error;stat.max;spect.line.eqWidthintnullablee_EW-Hd[1/1]? Lower uncertainty in EW-Hd0.1nmstat.error;stat.min;spect.line.eqWidthintnullableAS-HdJ/ApJ/950/95/table5Redshifts and velocity offsetszHW10[1.56/3.54]? HW10-based redshift (3)src.redshift;pos.heliocentricfloatnullableDvi-HW10[-2720/2130]? HW10-based velocity offsetkm/sphys.veloc;arith.diffintnullablezPipe[0.064/3.55] SDSS Pipe-based redshift (4)src.redshift;pos.heliocentricfloatDvi-Pipe[-146280/1850] SDSS Pipe-based velocity offsetkm/sphys.veloc;arith.diffintSDSSSDSS object designation (JHHMMSS.ss+DDMMSS.s) as in Table 1; column added by CDSmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSDSS object designation (JHHMMSS.ss+DDMMSS.s)meta.idcharzSys[1.56/3.54] Spectroscopic redshift (1)src.redshift;pos.heliocentricfloatzCiv[1.56/3.53] CIV-based redshift (2)src.redshift;pos.heliocentricfloatDvi-Civ[-3030/820] CIV-based velocity offsetkm/sphys.veloc;arith.diffintJ/ApJ/950/95/table6Linear regression coefficientsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMethodUV-based redshift methodmeta.notecharSize[118/121] Sample sizemeta.number;src.sampleintcoeff[abg] Regression coefficients (a={alpha}; b={Beta}; g={gamma})meta.codecharValue[-2589/1156] Coefficient valuestat.fit.paraminte_Value[36/536] Error on the coefficient valuestat.error;stat.valueintt-val[-6.05/4.15] t-value of the coefficientstat.fit.paramfloatJ/ApJ/950/95/table7Linear regression coefficients for each redshift binrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMethodUV-based redshift methodmeta.notecharbin[1/3] Redshift bin (1)src.redshift;em.binintcoeff[abg] Regression coefficientsmeta.codecharValue[-4802/6314] Coefficient valuestat.fit.paraminte_Value[46/2670] Error on the coefficient valuestat.error;stat.valueintt-val[-6.02/4.21] t-value of the coefficientstat.fit.paramfloatSize[12/71] Sample sizemeta.number;src.sampleint